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Hello, I just joined today after searching for an answer to what seems like an impossible question. I have a 2007 Snapper 250Z with a Briggs 20HP Intek V-Twin. I bought the mower new and have handled all the maintenance myself. I am a long time motorcycle tech so I know my way around an engine. This has me boggled though - During the last season my mower has began to use just under a quart of oil during each and every cut (roughly 2 1/2 acres). Here's the kicker - it doesn't smoke or leak. To use that amount of oil I should be able to spray for mosquitoes as a side job. I was running a Wix filter and some non-Briggs oil and even though I had my doubts I went back to all Briggs parts and it still does it. I removed the engine breather and noticed the oil collector was completely saturated and the reed valve in there was stuck open about 1/16th of an inch. I wasn't sure if this was normal (it didn't seem right) so I ordered a new valve and oil collector. I also noticed when I had the intake off that there was A LOT of carbon build-up on the valves - especially the left cylinder. This cylinder was lower in compression than the right one - Left:95 Right:120. Obviously this isn't good so while I was waiting for the new parts to come in I did a seafoam soak in the intake runner. I got all the parts in today and checked compression again - Left 115 Right:125. Better but still further apart than I like to see. So since I did not remove the head I figured I would run a good dose of Seafoam in the gas and go run the mower to mulch up all the fallen leaves in my yard. I ran it for a good 2 hours and immediately checked the oil level and then drained it. It came out BLACK, so the Seafoam was doing its job, but the level was still down a bit. Not quite as much as before but right at the bottom of the hatch marks on the stick. While it was still warm I put the filter back on, reinstalled the drain plug, and put 2 quarts of mineral spirits in it and let it sit for about 15 minutes. I then drained it out - it came out dirty at first, but cleared up. I then ran a quart of oil through it just to see how it came out. It drained crystal clear. This is where I am at this point. I am going to get a new filter, oil, and spark plugs tomorrow and hope for the best. Oh also the spark plugs were BLACK with carbon so I cleaned them before running the mower today and when I was done they were dirty again - not as bad, but not right.
I think I am on the right track, but this has me scratching my head. I have changed the oil religiously (twice a season) since it was new. I adjust the valves, replace the air filter and prefilter, replace the plugs, and replace the fuel filter every year. Way sooner than it calls for, but the parts are cheap so why not. How can an engine be using this much oil and not smoke or leak - Any idea's??????

wow!.....i think you have a factory defect engine.....i would think you would see more smoke...but ive had sneaky oil burning cars before......i dont like additives and dont use them except in desparation.....ive had satisfactory results from LUCAS oil treatment...beware[ its thick stuff!]

Thanks for the reply. I know it seems like an impossibility, but it doesn't smoke (besides the normal little puff at start-up due to choke being on). If I hadn't been witnessing it for the last season I wouldn't believe it. One thing I have considered is - Is it possible that somehow the recommended amount of oil is too much? It calls for 64 ounces according to the manual. I am relating it to my motorcycle knowledge and one of the bikes that I know of that is prone to carbon build-up is usually due to overfilling the oil because the dip stick isn't really accurate.
Also is it normal on these engines for it to take a long time for the oil to drain. My snapper has the convenient hose with the plug in it and even with the motor hot it doesn't come out real strong - it isn't dripping, but just has a tiny stream. It takes about 15 minutes for all the oil to come out.

The next steps to your engine at least from a dealer standpoint would be a leakdown test and a crankcase vacuum test. The leakdown to check for any excessive leaks past the head gasket, valves, rings. the crankcase vacuum test to check for air leaks preventing it from maintaining proper vacuum.

I let my oil drain for about 1/2 hour.
Always seems like it takes forever.

What weight and brand of oil have you been using ?
What weight and brand did you use before ?

Sammy the Red said:

I let my oil drain for about 1/2 hour.
Always seems like it takes forever.

What weight and brand of oil have you been using ?
What weight and brand did you use before ?

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Ok so my drain time is normal then.

I have used either SAE30 or 10W30. It was always changed with SAE30, but a couple times when it was low I topped it with 10W30 b/c it was all I had. It has either been Briggs oil or whatever brand O'reilly sells for mowers. There were 2 oil changes that I recall when I didn't go get Briggs parts and ended up at O'reilly's getting a Wix filter and whatever off brand oil they have for mowers.

ILENGINE said:

The next steps to your engine at least from a dealer standpoint would be a leakdown test and a crankcase vacuum test. The leakdown to check for any excessive leaks past the head gasket, valves, rings. the crankcase vacuum test to check for air leaks preventing it from maintaining proper vacuum.

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Hey Ilengine
Could it be migrating to the transmission somehow?

115 and 125 compression I would say is normal compression, only 10lbs different is good. You will find that on any normal engine. You say it is using oil and not smoking, I have also seen that. For using oil the first thing I would check would be the intake valve guides.

reynoldston said:

115 and 125 compression I would say is normal compression, only 10lbs different is good. You will find that on any normal engine. You say it is using oil and not smoking, I have also seen that. For using oil the first thing I would check would be the intake valve guides.

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You might be on to something. When looking down the into the head I could see there was a huge amount of carbon around the intake valve. I assume it was causing the valve to not close all the way and that was the reason for the first 90 PSI reading. After soaking in Seafoam for a few days it jumped to 115. I read on another forum to pull the valve covers one at a time and start the mower and look for leaks. Supposedly the common head gasket failure spot will be evident with it running. For the record the engine runs great and there is no noticeable loss in power. If it wasn't for it using more oil than a 2 stroke I would never know there was an issue. For the life of me though I can't wrap my head around an oil loss with no smoke or leak! Where does it go?!?!?!

You will find it is a lot like a motorcycle or any engine yes it can burn oil and not smoke. Seeing you have a lot of carbon around the valves and not smoking I would still be checking the valve guides. When the intake opens you have vacuum around the valve head and if the guide is loose you are sucking oil down pass the loose guides. On cars or truck they have valve stem seals but I never came across that on mower engines but maybe there is such a thing?

reynoldston said:

You will find it is a lot like a motorcycle or any engine yes it can burn oil and not smoke. Seeing you have a lot of carbon around the valves and not smoking I would still be checking the valve guides. When the intake opens you have vacuum around the valve head and if the guide is loose you are sucking oil down pass the loose guides. On cars or truck they have valve stem seals but I never came across that on mower engines but maybe there is such a thing?

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Well I don't claim to know it all about motorcycles but I am a pretty damn good wrench. I am always up for learning new things though and a good tech will admit that he learns new things on a regular basis. Can you explain how an engine can burn oil and not smoke it out. I know some slight leaks aren't seen until the RPM's are high. GM has an issue with the newer vortec engines burning oil at high rpms that the driver will never notice because it is so slight, but we are talking about 1/2 to a full quart in 3000 plus miles. I am burning at least 1/2 a quart every couple hours. That should be very visible coming out of the motor somewhere. Please teach me something new.

If it isn't leaking oil and using oil now it has to go someplace. I would say it is burning it up clean and if you had white smoke would be not burn up oil. Ever see a cold diesel start and a big white cloud of smoke come out it till it gets warm. That is unburned fuel oil. The same thing for the motor oil. It gets hot and burns clean. I don't know what else to tell you other then valve guides and the next step would be rings. Unless some other reason the oil is getting into the combustion chamber like a vacum line or vacum leak. Now some one said leaking into the transmission, but with that wouldn't the transmission be over full in time. Besides that I don't think to two of them come together. The best of luck on this.

Nick

One time, I bought some brand name oil that was on sale. Changed the oil in my truck and my girlfriends truck. Both were V-8's, both in good condition. Her truck started to using a quart of oil every day. She was not happy. The very next weekend I bought the brand of oil her truck had been used to and changed oil and filter. It stopped using oil when it got what it had been used to. My truck, never made a difference.

Some engine manufactures say that using a multi grade oil will increase oil consumption.

Go back to using the B&S 30wt oil or a quality brand name 30wt oil and see if oil use is reduced.

Sammy the Red said:

One time, I bought some brand name oil that was on sale. Changed the oil in my truck and my girlfriends truck. Both were V-8's, both in good condition. Her truck started to using a quart of oil every day. She was not happy. The very next weekend I bought the brand of oil her truck had been used to and changed oil and filter. It stopped using oil when it got what it had been used to. My truck, never made a difference.

Some engine manufactures say that using a multi grade oil will increase oil consumption.

Go back to using the B&S 30wt oil or a quality brand name 30wt oil and see if oil use is reduced.

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Now that is another good idea:thumbsup:

reynoldston said:

Now that is another good idea:thumbsup:

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I thought of that and the last oil change which was only a couple months ago is when I used B&S 30W oil and filter. Now this was before I replaced the breather valve and got some of the carbon out of the motor so who knows. I have to work until about 3:00 today and then I am going to get a new filter and oil again. I also plan on doing a leak down and vacuum test. Does anyone know how much vacuum I should pull? Thanks for all the input - I will definitely post my results.

RobertBrown the engine and transmission are two separate units so its not going between the two. Reynoldston the briggs does use a seal on the intake valve.

Mr. Shamrock said:

I thought of that and the last oil change which was only a couple months ago is when I used B&S 30W oil and filter. Now this was before I replaced the breather valve and got some of the carbon out of the motor so who knows. I have to work until about 3:00 today and then I am going to get a new filter and oil again. I also plan on doing a leak down and vacuum test. Does anyone know how much vacuum I should pull? Thanks for all the input - I will definitely post my results.

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Sure sounds good, but just what is a leak down and vacuum test, and what is it going to tell you? I am guessing how much vacuum in the intake manifold when the engine is running for vacuum test? It seems like I have seen a test where you put compressed air into the the cylinder too see how much blow by you get by the rings or check for a blowen head gasket. Never heard of a leak down test. Is a leak down test vacuum in the crankcase to see leak bypass the rings?? It seems you would want the valves open for that test. You must need some kind of vacuum pump for a test like that? So just what information are you going to get from this test for oil consumption? ( Does anyone know how much vacuum I should pulll) From where ?

reynoldston said:

Sure sounds good, but just what is a leak down and vacuum test, and what is it going to tell you? I am guessing how much vacuum in the intake manifold when the engine is running for vacuum test? It seems like I have seen a test where you put compressed air into the the cylinder too see how much blow by you get by the rings or check for a blowen head gasket. Never heard of a leak down test. Is a leak down test vacuum in the crankcase to see leak bypass the rings?? It seems you would want the valves open for that test. You must need some kind of vacuum pump for a test like that? So just what information are you going to get from this test for oil consumption? ( Does anyone know how much vacuum I should pulll) From where ?

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I googled a leak down test and my first guess was right. Compressed air into the cylinder and a no more then a 10% lost of air going out. Not very clear on how this 10% is measured? You must have the right equipment for this test and it will tell you a lot without a tear down. good luck

Nick

Small engines are measured in inches of water vacuum not mercury like most things. It is preformed with the engine running with using a water mamometer or the special small engine vacuum gauge. Briggs talks about crankcase vacuum testing but doesn't publish what the correct amount is. I did one on a briggs intek twin a couple of years ago and got 10 inches which according to tech support is too low.

The measuring apparatus is hooked up with a modified dipstick cap with the engine running to measure. It using a water mamometer you have to clamp off the line going to engine when you start it to prevent the water from being sucked into the engine.

The leakdown test is preformed at top dead center with a special leakdown gauge that has green,yellow, and red areas with the amount of air loss measured on the gauge. Most are calibrated at either 90 or 125 psi input air. The you find out where the air is leaking from. The rings, head gasket, or valves.

What does this crankcase vacuum test telling you that you had only had 10 in.s ? Now remember we are looking for oil consumption. Maybe the crankcase vent isn't working right or piston ring blow by? This all sounds like a good test to me. I have to say I do the pressurize cylinders test at line pressure to find a bad piston, valves or head gaskets.

Is the valve cover on the cylinder in question filling up with oil?
Have you checked to see if the oil return in the cylinder head is clear so the oil can go back to the crankcase?
Also I would make sure that you have the correct dipstick and fill to just below the high level mark, run the engine to warm it up and recheck. You may be overfilling it if you put in the amount of oil that is specified which is a dry engine fill amount.
Are the cooling fins on the cylinders clean?

Mad Mackie said:

Is the valve cover on the cylinder in question filling up with oil?
Have you checked to see if the oil return in the cylinder head is clear so the oil can go back to the crankcase?
Also I would make sure that you have the correct dipstick and fill to just below the high level mark, run the engine to warm it up and recheck. You may be overfilling it if you put in the amount of oil that is specified which is a dry engine fill amount.
Are the cooling fins on the cylinders clean?

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It was not the last time I adjusted the valves. I haven't checked the return. I have to think the dipstick is correct because when I do an oil change and add 64 ounces it puts it right on the mark. The cooling fins and entire engine is very clean. I am going to pull the valve covers again and check. I was able to get the oil, filter, and new plugs today, but with the in laws in town I didn't get a chance to mess with it yet. I really appreciate all the info and idea's!!!!

There are three groups of numbers on a Briggs engine. Engine model, Type, and Code. Write these numbers down and go to the Briggs & Stratton web site, click on support, type in the engine model and type to find the parts manual for your engine. It is in pdf format and easily downloaded and stored in the "my documents" on your computer or a flash drive for future reference if you use Windows. There are B&S service manuals also available but must be purchased at a power equipment dealer or on line.

Mad Mackie said:

There are three groups of numbers on a Briggs engine. Engine model, Type, and Code. Write these numbers down and go to the Briggs & Stratton web site, click on support, type in the engine model and type to find the parts manual for your engine. It is in pdf format and easily downloaded and stored in the "my documents" on your computer or a flash drive for future reference if you use Windows. There are B&S service manuals also available but must be purchased at a power equipment dealer or on line.

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Thanks - that is where I ordered the crankcase breather, intake gaskets, and oil collector. It definitely makes it easier to visualize everything. Their shipping was quick too.

Happy Thanksgiving to everyone!

ILENGINE said:

RobertBrown the engine and transmission are two separate units so its not going between the two. Reynoldston the briggs does use a seal on the intake valve.

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I have never seen valve seals on a small engine, but was wondering if something after market? Never tryed or looked into it but just hoping for a easy fix for oil consumption. Just a stab in the dark??

It does have one according to the parts diagram.

Mr. Shamrock said:

It does have one according to the parts diagram.

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I said aftermarket so it won't be in any parts diagram, but also doubt if there is such a thing. I would also say no oversize valve stems or replaceable valve guides. I would say if the valve guides are shot it would be new head time unless a machine shop can repair them? I know when I was working in truck repair we would repair valve guides a lot. Now that I am just doing small engine repair it is just something I haven't ran across.

You won't get an accurate compression reading because of decompression. There is no such thing as valve seals it is valve seats which is metal on metal the edge of the valve head on the head

Briggs92 said:

You won't get an accurate compression reading because of decompression. There is no such thing as valve seals it is valve seats which is metal on metal the edge of the valve head on the head

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I would guess you don't know what valve seal are. They are a rubber type seal that goes on the rocket end of the valve under the valve retainer and spring. You will find them on most all car and truck engines. What they do is prevent oil from running down valve stem into the combustion chamber. This has nothing what so ever to do with the valve seats in the head. When the intake valve is open and drawing in fuel there is also a vacuum under the head of the valve. This vacuum will draw oil into combustom chamber if the valve guide is worn and too loose.

Sorry I misunderstood. For some reason I thought you guys were thinking that there was a seal where the seat is. What is the model and type of this engine? I can find out if it has valve seals

Briggs92 said:

Sorry I misunderstood. For some reason I thought you guys were thinking that there was a seal where the seat is. What is the model and type of this engine? I can find out if it has valve seals

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Mr.Shamrock has a B&S Intek that is using oil but not leaking or smoking, but want to know where the oil is going. I guess we are getting away from the original question. He was going do do some test but never got back to us yet.

I spent a little time on the mower today and put new oil, filter, and plugs in it. I checked the compression again and it is left:115 and right:125. I pulled the valve covers and there was a little oil in there but I don't think any more than normal. One thing out of the ordinary is the oil that I drained and what was left in the head, which is not very old at all, was real black. If I wasn't the one changing the oil I would swear it hadn't been changed in a very long time. I actually took a grinder and opened the old oil filter up and besides being really dark there wasn't anything that caught my attention. There has to be a serious carbon build up in the motor somewhere. I probably have one more cut this season and then I think I am going to pull the heads to see what the deal is. There is no reason why oil that might have 12 hours of run time should be so dark. Every other mower I have had the oil looked almost new when I changed it each time. This really has me stumped!!!!!
Oh I also let it run for a little while with the air filter removed to see if there was any sign whatsoever of oil burning there - none and the filter and filter housing are both bone dry.

One thing I thought of today after racking my brain for anything abnormal since I bought this mower new is - When I bought it I had the ninja mulching kit put on it which consists of mulching blades and a block off plate for the side chute. When I was ready to put new blades on I bought a set of gator blades for it. The gator blades when combined with the block off plate made for a VERY dusty ride. I used it for about 4 or 5 cuts like that before I had enough and contacted the manufacturer of gator blades. They told me I should not use them with the block off plate so I immediately put the side chute back on. I have since went back to the snapper blades and the block off plate, but I wonder if the extreme amount of dust being sucked in could do something. I blew out the fliter and prefilter after each cut and they were nasty, but I am sure some probably got by. Again this was only a few cuts, but that is the only thing I can think of that stands out as out of the ordinary since I bought the mower.

I know I said I was going to do a leak down test and I still am. I had people coming over today for the football games so I didn't have a lot of time. I will post back with my results.

Keep us updated on this leak down test and don't forget the vacuum test.

I did a leak down check and what I think is a vacuum check. I have never performed a vacuum check on a cylinder in all my 17 years or wrenching. Anyway, on both cylinders air was heard to be escaping from the exhaust and through the oil fill tube. I loosened both rockers completely to make sure both valve were completely closed. I don't have a gauge to see what percentage of loss I was getting, but with just the ear test they both sounded the same. Now the vacuum test I just hooked my Mightyvac handheld tester to the same adapter I used to put the compressed air in the cylinder. I could not get either cylinder to hold a vacuum and the only difference was if I pumped the tester on the cylinder with the higher compression I could get 5 inches Hg and then as soon as I quit pumping it dropped to zero. On the lower compression cylinder the needle would just barely move when I was pumping it. Not even enough to get it to 1 inch Hg. Any idea's?

At least you are one step closer to getting an answer!

So you are getting blow by pass the rings which to me you will get some of. So I just don't see what it is telling you? You have to measure this some how to know what it is telling you. Getting blow-by pass the exhaust valves I would say isn't right. I would check them for carbon buildup or it may be time for grinding the valves and valve seats which at that time check the valve guides. You did say you loosen the valve adjusters so you don't have a tight valve. Now I guess I still don't understand what you are doing with the vacuum test. I just never heard of the test you are doing? I thought the vacuum test had something to do with measuring the vacuum in the crankcase with the engine running??? My thought on the vacuum crankcase test you would want negative pressure at the fill tube and if positive you would have bad piston rings? Maybe you could explain to me what your vacuum test is going tell you as far as oil consumption gos? I am always willing to learn.

With leak down testing generally the following:
A leaking exhaust valve will leak air into the exhaust system.
A leaking intake valve will leak air into the intake manifold/carb/throttle body, etc.
Piston rings will always leak air by, how much is too much is the question, but this leak goes into the crankcase and noticed at the dip stick tube and or crankcase vent.

Your right I did the test wrong - brain fart. Like I said I have never had to do a crankcase vacuum test, but apparantly it should be performed with the engine running. I am done testing it - I guess I need to pull the heads after I do my last cut and see what it looks like. I wish I had a boroscope so I could just take a peek inside the spark plug hole. I still can't comprehend how a little carbon build-up on the exhaust valve would cause this scenario?!?!?!?!

What do you guy think of this - connect my compression tester hose (without the gauge) to each cylinder. Use a product like Seafoam and spray it down the hose until it comes out - keeping the hose pointed up and making sure it is higher than the spark plug hole. So this should fill the inside of the cumbustion chamber with the Seafoam. Let it sit for a few hours or even over night and then do the other cylinder. Then just remove the hose and turn the motor over to push out all the liquid. This should loosen up the carbon. This is basically what I did to the intake side only simply filling up the intake port which enabled the valve to be completely covered in the cleaning liquid and there is no leakage at all there.

I wouldn't leave any liquid of any kind in an engine overnight and particularly any volume of it.
You need to get and read the parts manual and service manual for your engine so you know how compression release systems work and how they affect compression testing and leakdown testing results. Unless your engine has more than 500 hours of operation on it I doubt that it has much carbon buildup anywhere in it.
If this B&S Intek twin that has the air filter cover with 4 screws holding it down and is more than 3-4 years old then there may be a problem with the air filtering system. Some V twin models suffered from dust particulate injestion as the air filtering systems had air leaks down stream from the air filter. This dust injestion causes premature piston ring and cylinder wall ware which increases crankcase pressures beyond what the engine is designed to deal with and in time engine failure.

I agree with Mad Mackie invest in a good service manual for this engine.

Mad Mackie said:

I wouldn't leave any liquid of any kind in an engine overnight and particularly any volume of it.
You need to get and read the parts manual and service manual for your engine so you know how compression release systems work and how they affect compression testing and leakdown testing results. Unless your engine has more than 500 hours of operation on it I doubt that it has much carbon buildup anywhere in it.
If this B&S Intek twin that has the air filter cover with 4 screws holding it down and is more than 3-4 years old then there may be a problem with the air filtering system. Some V twin models suffered from dust particulate injestion as the air filtering systems had air leaks down stream from the air filter. This dust injestion causes premature piston ring and cylinder wall ware which increases crankcase pressures beyond what the engine is designed to deal with and in time engine failure.

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Thanks - that is the information I was looking for. I thought I had a carbon build-up down around the intake valve, but it very well could have been dust buid-up. Also I am sure I didn't help matters by using the gator blades with the deck block off plate which caused a dust storm while mowing. I do have the 4 screw filter housing and I bought this mower in 2007, but I believe it is a 2006 model. That would explain my oil turning black so quickly as well. I wonder if B&S is doing anything with this situation.

reynoldston said:

I agree with Mad Mackie invest in a good service manual for this engine.

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I guess it is a good idea to have a manual but I know one thing - if this motor fails it will not get replaced with another B&S!

I have been communicating back and forth with a rep from B&S and I just sent him an e-mail about possible dust ingestion. I will let you know what he says.

My 2008 Scag tiger Cub Zero turn machine has a 26 HP B&S ELS series engine, basicly an Intek. It has a two screw air filter cover and supposedly the airfilter problems have been corrected. These machines are all very dusty and the engine is in the worst location for the dust, particularly with the collection system running. I have to replace air filters every 10-20 hours and I shake the dust out after every use of the machine. I never use hp air to clean air filters, it destroys the filter elements ability to catch small particles. I buy these filters by the case lot, 4 per case on line. Had I known about the dust problem with ZTR machines I would have bought one with the HD dual particle separating type Donaldson filter system. This would have forced me into a Kohler or Kawasaki engine neither of which I'm crazy about so I probably would have bought a different make of machine. I also change oil at 25 HR intervals with a filter change at 50 HRs. I use 5W30 synthetic engine as specified in the operators/service manuals for this engine. I use an oil evacuation system and I can see that the oil gets very dark. ZTR engines are run a 3,600 RPM most of the time, nature of the beast so to speak. Almost 400 HRs on my Scag, still running strong. My garden tractor has a B&S Vanguard 18 horizontal engine with 250 HRs on the engine and 2,300 HRs on the machine, recent repower.

You know the more I think about the dust thing the more it makes me think about how dry it was when I first bought this. We were in a massive drought around here back then and for at least the first year or more of owning it. I have gone through more air filters than I have with any other mower. I guess that is one downfall to the rear engine. I did get a response back from B&S today...

Thank you for your inquiry.

If it appears to be a ring issue I would have an authorized dealer inspect the engine, if they determine what the rings are worn due to dirt ingestion caused by a defect in materials or workmanship we can try and assist you with this. I have included the dealer locator below to assist you with finding one in your area.

I guess that is about what I expected. My fear, of course, is they get it apart and B&S says they aren't responsible and I end up with a huge bill. I think I am going to call some of the local dealers tomorrow to see what they say.

If the B&S engine on your machine is out of warranty then you WILL end up with a large servicing bill.
Being a part commercial operator and part service tech, in recent years I have repowered some of my machines and done the same for customers. This gives you a new engine with a new warranty, minimum down time, and usually costs the same or less than an engine overhaul. 15 years ago there were three engine overhaul shops that I dealt with, they are now out of business and I don't have a clue as to where I would get major machine work done other than several dealers in the Michigan/Wisconsin area whose small engine work has been good. My last few repower engines have come from Tulsa Engine Warehouse. I have the customer purchase the engine and have it delivered to them and then I take over from there. This way the warranty, the shipping address, and owner are all the same person/business. I don't have to put out the dollars and if the customer changes their mind I'm not left hanging with an engine that I don't need and the warranty clock ticking away. I also prefer to do diagnostics on their machine at their place, this way I don't end up with piles of junk machines that would cost me dollars and time for me to dispose of. I have performed these services in one of my trailers where the customer didn't have a suitable place to perform the diagnostics.
Mad Mackie in CT:biggrin::laughing:

After the horror stories I have heard about some of these local shops I may just run it till it blows. Now that I know a little more I can keep an eye on those things a little better. I never thought about the mulching kits in that way - after all the one I have is a factory option. I guess I was a little naive due to my father having snapper mowers that lasted forever with little to no problems and minimal maintenance. I can hardly remember him ever even changing the oil on one machine. It was at least 15 years old and ran like new. Someone stole it from his shop or I bet he would still have it.

Like mentioned before I am in the motorcycle business and there isn't anything I can't do to one. I do repairs all the time that have already been to some of our local shop and aren't fixed. It kills me to think that someone can get so frustrated with a shop they are willing to give up there hard earned money just to get there property back so they can take it elsewhere for the same issue. I just did a older Honda Magna that a guy paid a shop $1200 to rebuild the crabs, skin the tank, and get it running right. It came to me with dirty carbs, clogged petcock, broken fuel lines and not running at a all. All I could see they did right was creme the tank FOR $1200!!!!! This is what I am afraid of and would rather use the mower for as long as I can and then upgrade the motor when I repower.

Question: My mower has a 20HP - what is the rule of thumb on a mower for repower as far as how much bigger is OK? Is it like a boat where there is a max HP rating? Obviously I am not going to throw some monster on it, but would a 22 or 24 HP be ok?

I called 2 shops this morning and the first one (after giving him my whole story) tells me they don't do a lot with residential mowers, but they would be happy to look at it for $95/hour. The second shop told me they would look at it for a $30 diagnostic fee and would be very happy to work with me through B&S to try and get as much as they could from them. He said normally if it is something that is out of warranty (which it is) and is found to be a "abnormal" thing that is a manufacturer defect B&S will sometimes provide the parts and I would just be responsible for the labor. They charge $60/hour which isn't bad for a shop. He did say something that triggered a thought though. He mentioned they would test it with and without the PTO engaged. Sounds obvious, but when looking for smoke I have been off the mower which obviously I have to have the PTO disengaged for. So I went out and fired the mower up and let it warm up - I then sat backwards on the mower with my knees in the seat and sure enough when the PTO is engaged I get a slight puff of smoke each and every time. I am wondering that when it is in use and under load of the PTO and the reistance of the grass is it slightly smoking and I just don't notice it from the dust and grass clippings flying around - Plus I am facing the wrong way. That has to be it. Well at the very least I don't think I am insane anymore with a mower using oil and not smoking or leaking. As far as my next step - well I think I am just going to use it like it is and repower or rebuild later on. Hopefully I can get through a few more seasons with it like it is. Thanks for all the help!!!!!

A good diagnosis and confirmation of the results is best.
As for repower, get the numbers from your Intek, usually on one rocker cover, the model which is a 6 digit number, the type which usually is a 4 digit number followed by a two digit which could be letters and/or numbers, and the code which is also the manufacture date and location.
Go to both Small Engine Warehouse and Tulsa Engine Warehouse and check out the repower possibilities. Many times a power increase can be available and this is OK with a remote fuel tank. The configuration of the engine is deternined by the code number, and crankshaft length and diameter are critical. On the Small Engine Warehouse web site they have a repower link and you can get repower info directly for your machine there if it is available. The Tulsa Engine Warehouse site has a link to email them and they usually respond quickly. Get all the info about your machine and engine before you go searching, model s/n etc.
Engine mounting configurations have been standardized to an extent, but it is best to stick with the same make and branch line as original engine.
Have fun!!!
Mad Mackie in CT:biggrin::laughing:

I have only operated a rider mulching mower for just a short time, but I did notice that the ground speed has to be reduced to keep the mulched output from clumping and slowing down the deck. I would think that mowing more often with a mulching mower is needed. I mow my own lawn in hot weather to 4 1/4"-4 1/2" height with open discharge, sometimes three times a week, shorter in fall with collection. The collection blower on my Scag Tiger Cub is easily removed or reinstalled. All my customers are mowed with collection and I can dispose of the clippings at or near their locations, if not then they become someone elses customer!!!
Mad Mackie in CT:biggrin::laughing:

Guys, how often should oil be changed in your average mower? Is it different for push-behinds and ride on mowers?

Thanks.

Briana said:

Guys, how often should oil be changed in your average mower? Is it different for push-behinds and ride on mowers?

Thanks.

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For your average homeowner once a year is good for push or riding mower. Usually done in spring before the mowing season begins.

Other than that everyone has a preference 25hrs, 50hrs, or 100hrs. Depends on the machine and how it's used.

I change my tractors twice a year . Every other machine once a year . The parts are so cheap I change plugs and filters frequently . My stuff is a healthy 25+ years old .

Oil change once a year is perfect... Check oil level every-time you use it is also a good idea.. :smile:KennyV

Sorry for taking so long, but obviously over the winter the mower wasn't a huge priority and I was hoping that my Sea Foam soaking was going to magically cure it - wrong. I cut the grass the other day and again it used about 1/2 a quart. So I ordered a repair manual and a gasket set and tore into it today. Man I can't believe how much of a carbon build-up there was. Here is a picture of the worse side...



Here is more of a profile shot. It is the thickness of a nickel!



I didn't get a shot of the the worst head, but here is the other side. You can't really tell it from the picture but the valves were definitely not seating properly...



So I started the cleaning procedure...







The heads are going to soak for at least a few hours and maybe overnight so I made a nice hot tub for two...



And one final pic of my poor tore down Snapper...



Anything you guys recommend while I have it apart? Obviously I have a new gasket set in hand with new valve seals. I plan on changing the oil too. It's no wonder my oil was turning black after a single cut.

If the valves were not sealing that can cause increase oil usage. Check to see if you can still see the cross hatch pattern in the cylinder walls. If there is a real smooth surface it may have some dirt ingestion causing rapid wear. Check to see if there is a ridge at the top of the cylinder to indicate excessive wear.

ILENGINE said:

If the valves were not sealing that can cause increase oil usage. Check to see if you can still see the cross hatch pattern in the cylinder walls. If there is a real smooth surface it may have some dirt ingestion causing rapid wear. Check to see if there is a ridge at the top of the cylinder to indicate excessive wear.

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They definitely couldn't have been sealing. There was little specs of carbon right on the edge of the valve where they meet the head. I will check the cylinders tomorrow. I just got back from dinner and went out there and scrubbed some more on the heads and the chemical is slowly dissolving the carbon. By tomorrow it should definitely be good to go. Man I hope this is all that was wrong with it! I know one thing - checking the air filter will now be part of my pre-cut inspection. Thanks for the input!

I got it all back together and it runs great (but it has always run great). I don't know if it is just wishful thinking or what but it seems to run a little smoother. It still baffles me how a mower that doesn't smoke (besides a very slight puff when the PTO engages), doesn't leak, and runs fantastic can go through so much oil. Hopefully it is fixed though. I didn't change the oil because I am going to cut the grass tomorrow and change it when I am done that way it will be good and hot. So I will update tomorrow to let you know if it is fixed or not.

Well the results are in. I topped off the oil and added a little Sea Foam hoping to get a little more carbon out if possible. I then cut my yard. When I was done the oil level was down just a little. I immediately opened the drain and the oil came out BLACK! This oil has only been in the mower for 2 cuts (about 3 hours of run time). I replaced the oil and filter and went ahead and threw some new spark plugs in there as well. I then cut the yard again (I know kind of a waste, but I just had to know if this fixed it or not). When I was done the oil level was right on the mark and very clean. So I am very optimistic that this did the trick AND my yard has a nice criss cross pattern from the 2 cuts!

UPDATE: Cut the yard again today and the mower used exactly 6 ounces in the hour it was running. It seems to have used less although I am cutting more frequently and I raised the deck one notch so there is little to no strain on the motor which might be a factor. So it looks like new rings will be needed to fix it right. Does anyone see an issue with using SAE40 oil through this season? I will tear back into next winter. It still doesn't put out any visible smoke and runs as good as new. I guess at $3.99 a quart and using 6 ounces per cut I could get 5 cuts per quart or in other words it will cost 80¢ in oil per cut. I guess I could live with that, but I won't!

Another unfortunate update - My work did absolutely nothing. My dad borrowed the mower today and cut his yard and he always cuts the yard for his widow neighbor. The mower runs for 2 1/2 - 3 hours to cut both. When he brought it back it was 20 ozs low. 20 out of a 64 oz system is pretty bad. I will never understand how this thing isn't smoking like a mosquito sprayer. It makes zero sense to this guy!

I really believe it is the quality of oil .
We get many machines in with internal damage . The owner might check the oil one week . Use the machine 4-5 times then they bring it in knocking or seized (always has clean full oil then)
My older tractors do not smoke but use 1/2 qt oil every month .

SONOFADOCKER said:

I really believe it is the quality of oil .
We get many machines in with internal damage . The owner might check the oil one week . Use the machine 4-5 times then they bring it in knocking or seized (always has clean full oil then)
My older tractors do not smoke but use 1/2 qt oil every month .

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I have kept an eye on the oil level. I won't lie and say I have checked it every single time I used it, but I guarantee there has never been a back to back unchecked use. Do you think it would make a difference to run some 40 weight instead of the recommended 30 to buy some time? It has had SAE30 from day one and most of the time it has been B&S oil. Not because I am that anal, it is just Lowes is right down the street so that is where I always stop to get oil. The other times it has been topped off with O'reilly's brand.
I can't help but think back to when I used this mower to do a favor for a friend who was managing a new housing development that had about 20 empty lots. I used it to cut the lots twice and it was a constant dust storm the entire time. That is also when I first discovered the low oil level. The lowest I ever seen it (which was the time I am talking about) it was a full quart low. Anyway, the damage is done.
I will probably start a new thread, but what are opinions on new engine vs. rebuilding this one? It seems there are a number of new 20HP B&S on eBay in the $650 range. I will be doing the work myself whether it is installing a new motor or rebuilding this one so labor is not a factor. Thanks!

Here's a variation of the "run it until it dies, even though it's leaking oil" approach. Use an oil additive like STP oil treatment designed for worn engines. That may slow the rate of oil consumption. If it's an engine that's going to be replaced anyway, why not?

Also, is there some way (short of installing a newer engine with an improved system) to improve the seal on the air intake system? It seems like this problem must be fairly common with these mowers and maybe someone has thought of a DIY fix.

:laughing: Please note that I have no experience with these riding mowers and that the STP idea may not apply to modern engines -- with emission control technology. :laughing:

Two-Stroke said:

Here's a variation of the "run it until it dies, even though it's leaking oil" approach. Use an oil additive like STP oil treatment designed for worn engines. That may slow the rate of oil consumption. If it's an engine that's going to be replaced anyway, why not?

Also, is there some way (short of installing a newer engine with an improved system) to improve the seal on the air intake system? It seems like this problem must be fairly common with these mowers and maybe someone has thought of a DIY fix.

:laughing: Please note that I have no experience with these riding mowers and that the STP idea may not apply to modern engines -- with emission control technology. :laughing:

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Yeah that is about where I am at - just run it till it dies. I just want to have a plan in place for when it does die. I sent all my engine info over to a parts place today for a quote on a replacement. I notice the newer motors have a differenent filter set-up that I wonder if it would work on my engine if I decide to rebuild it. The new one has a conical style instead of the flat filter and seems like it would do a better job of sealing. In the meantime I am going to try some thicker oil or an additive and now part of my precut inspection includes blowing out the air filter and wiping out the dust that gets past it in addition to topping off the oil. It will probably go a long time like this in my opinion. I just hate it when something isn't right!

I heard back from the folks at Lucas and here is a copy of what they had to say...

Allen,
You could add Lucas Heavy Duty Oil Stabilizer to your mower but keep the
treatment light - about 5 to 6oz. It will give your oil added film
strength and that might give you a strong enough seal on your rings to cut
back on oil consumption.
Best regards,
John Mingus

We have customers that say MOBIL ONE only or LUCAS only - if they don't request special oil the get a 30w - forget the brand - maybe Valvoline ?

I drained the oil today to try some Lucas and look how black the oil is. This oil only has about 6 hours (if that) of run time...



So I am going to try some of this to see if it helps...




It seems to me that maybe the mower is running too hot and cooking the oil. Does this make sense. There is no reason for such low hour oil to look that bad.

The Black in the engine oil is partially burned fuel, you are getting fuel dilution in the engine lube oil which is not a good situation. Something is causing an excessively rich fuel condition in the air/fuel mixture, could be the carb, air filtering, fuel pump, or a partially closed choke. Are the spark plugs and or the exhaust pipe sooty black?
Mad Mackie in CT

Yeah the spark plugs get sooty pretty quick and the exhaust isn't real bad, but it does have some. What is weird though is the motor runs perfectly. I would think a rich condition would cause it to load up and stumble. The last time I pulled the plugs to replace them I was amazed at how bad they were and how good the mower ran. When I did the head gaskets a few weeks ago obviously the carb had to come off and I removed the bowl and gave it a good inspection. Besides a little bit of dirt where the butterfly shaft goes into the carb body it looked extremely clean inside. I also blew out all the passages just to because I was there already. I do a lot of carb work in my motorcycle business so I am pretty good in the carb department. The air cleaner is new and I have been blowing it out after each use since I discovered the common dust ingestion issue with these motors. I haven't checked the choke to make sure it is opening all the way and that will definitely get inspected today. Thanks for the response!

A leaking fuel pump diaphragm can also let fuel pass directly into the engine.
Mad Mackie in CT

Mad Mackie said:

A leaking fuel pump diaphragm can also let fuel pass directly into the engine.
Mad Mackie in CT

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It would have to leak through the vacuum line going into the valve cover right? The float needle/seat would stop addittional fuel from entering through the carb (assuming it is working properly). Plus it would cause the oil level to rise. If it was the vacuum line it seems like it would affect just the side with the line ging to it which was the side that I initially suspected an issue with, but the other side had the worst carbon build-up. Unless the fuel entering that side was actually aiding in the carbon cleaning some. I will go out there now and pull the vaccum line off the pump to see if it is wet. Thanks again for the help!
I also checked the choke earlier and it was adjusted properly according to the manual and I can see it opening and closing properly.

Well you might be on to something Mad Mackie. I got a few drops of gas out of the vaccum port on the pump when I removed the line. Also there is a buildup of dirt around where the line goes into the valve cover. I just cleaned the valve covers then I had the heads off a few weeks ago. I am going to order a new pump and line and see if that helps. Thanks a million!!!!

Alright got it ordered - man of this ends up being the culprit I will definitely be :biggrin:

I am watching this closely. I have the same identical problem and am doing about the same things to try to fix. Have been searching the forums for an answer and i see a lot of Briggs engines using a lot of oil in a short time, but I have not seen anybody fix the problem most everybody looks to the valve timing, valves, and they have the carbon build up you mention. They also change the oil, filter, breather with no help. Hope you have the right solution.

I hope so too. I received the pump and vacuum line yesterday. Unfortunately they sent the wrong line. Apparantly there are 2 different ones for this motor depending on the date code and of course I got the wrong one. There is a shop not too far that has a few in stock so I am going to pick one up on my way home today. I am sure the grass will need to be cut over the weekend plus my dad's needs to be done (his grows way slower than mine) so it will get a few hours of run time on it. I will keep you posted.

I drove over to the shop that claimed to have 9 of the hoses in stock and, guess what, they had ZERO. I am done with that shop. I bought my mower from them and they have pretty much let me down each and every time I have went back for anything. The owner had the nerve to blame the misprint in the computer on his 13 year old son. Anyway, I made some calls and the nearest shop was 30 minutes away so I rode over there and got it. I also met a real nice shop owner who will be getting my business from now on. The pump and new line are installed so it is ready.

Hello Mr Shamrock. We have a 16hp briggs inteck twin on a simplicity. It has about 350-380 hours on it. If I didnt know better I thought I wrote this thread because I have pulled my hair out with oil usage also. I, like you, cant figure out where its going. Motor runs strong as can be and does not smoke. When pulling a big hill under full load I sometimes think I may see a faint hint of blue smoke. So faint, I cant be sure and it may be in my head. Compression was within 2 lbs of each cylinder. In 20 hours this year, it has already gone through 2 additional quarts of oil. Roughly, 3 oz per hour.

It has had briggs 30 weight in it since new with oil changes every 50 hours. I recently tried Rotella T 5w 40. No change. Im about to try Rotella 15w 40 because I have some and expect no change. I have not gone to all the trouble you have. The plugs look terrible after a while and I even wondered how in the world they would fire.

My engine has not had the best of maintenence in all honesty. My plan now is to change the oil every 25 hours give or take and keep a super close eye on the filter and make sure the fins are clean after each use. These engines from my research are notorious for poor filtratation and I suspect this is what happened in our case. My Dad ran it one time so long that it just quit only to find out the filter was clogged. I imagine the damage was done right then and there. I have now taken over since he cant any longer. One other time he said it just quit because the plugs fouled out.

The goal here is just to run it till she blows. I am simply trying to extend what life is left in it. The Simplicity is a super good mower and the engine still runs strong power wise but you have to add oil at each mowing. It typically goes down to the add mark after an hour to an hour and a half of running. I also added some Kreen (additive to clean up sludge) just as a long shot. I normally dont believe in additives but this stuff works good if you have a dirty engine and I figured I didnt have anything to lose.

I dont know what else to do other than to just run it and try to nurse what I can out of it.

I have a 17.5 briggs engine on a snapper rider. I change the oil and filter religiously with quality products. One month ago the engine (suddenly) started burning oil, way more than normal. I started reading the threads and decided to start with the easy stuff. While examining the engine I decided to pull the spark plug. It was not very tight (I.e loose) and when I pulled it, it was filthy. I put in new plug and tightened it to spec. Solved ????

I'll let you know after I mow this weekend.

May be lower compreesion on one cylinder due to valve problem. Check the valve guides to see if they have moved. If the exhaust valve guide has moved towards the piston it may be holding the valve slightly open. This will also lower the height of the guide on the rocker side allowing some oil to run down it and blow out the exhaust and not producing noticable smoke. gregjo1948

I lightly skimmed that whole turd, no where did he say that he replaced the head gasket/s, which is very likely the problem...