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17hp FC540V single cylinder Kawasaki on a JD 325. Bought the mower, did some general maintenance along with a lot of carb work. I've had the head off, cleaned the carbon off the piston head and valves, wasn't too bad. Cylinder was nice and smooth. Metal head gasket looked fine so i did not replace. No signs of any leaks.

Mowed with it yesterday for a little more than an hour, ran great, no problems at all. No smoke at all. Started it today and it smoked A LOT. That cleared out completely in about a minute. Mowed for about 30 minutes when suddenly a LARGE puff of blue smoke, obviously oil burning. It was so bad I was waiting for the head gasket to go but it didn't. It blew the smoke out for about two seconds then stopped. It started repeating that every 30 seconds to one minute. Still ran just fine but when it blew out smoke it was a lot of smoke. No noticeable loss of power.

So where should I start? Does this sound like a head gasket? Rings? Something else?

I had an old FC420 v motor that would blow smoke every minute then clear up,,what was happening was there was oil getting pushed through the breather into the air filter,,then the carb would suck it in and it would smoke...I never found out why the breather was dumping a few drops of oil into the carb every minute,maybe some sort of breather valve is bad??
The oil level was normal..my fix was to reroute the breather line into a small container and plug up the breather hole on the air box...I would dump the oil out of the canister back into the crankcase every other lawn cutting or so...worked great and ran it for years that way,,the motor still runs great!!

Im sure its a simple fix though,,just never figured it out.

Tom

Thanks Tom. Symptoms sound the same. Hopefully someone can explain what might be going on.

arch252 said:

Thanks Tom. Symptoms sound the same. Hopefully someone can explain what might be going on.

Click to expand...

Yes sir no problem,,Just do a test and remove the breather hose from the air filter box,,just let it hang down and put some duct tape over the nipple on the air box,,if the smoke stops and you see oil dripping from the hose you found your problem...I believe there is a valve for the breather under the valve cover that might need replacement,,its a small reed valve if If my memory serves me well.

Good luck!!

Tom

So that is definitely the source of the burned oil. There is a lot of oil coming into the breather through the tube. I am familiar with that reed valve inside the valve cover.

Question is: Is it just that the reed valve is allowing oil to get past it or is there another problem causing excessive oil into the valve cover? Is this a sign of worn rings, faulty head gasket, worn valve stem guides or seals, or something else? I'm wishing it was just that reed valve but something is telling me it won't be that simple.

All of the above. Singularly or all together.
No way to diagnose properly without full disassembly.
Usually worn out rings will blow smoke continually.
However so will a very bad head gasket.

So start with the head & head gasket.

What we did not alert you to is to check the oil.
If the oil is thin and has a gassy smell or is overfull then you have a problem with fuel seeping into the crankcase and thinning the oil.

Oil was not thin and did not smell of gas. Oil level was on the lower end of the normal range. The head gasket won't be bad, I'll start there and hope for the best. Thanks Bert!

Like I said,,I ran that 420v for years commercially after this happened and it never burned another drop,,i did have to empty the little plastic can into the crankcase every few hours though but the machine still made me a boat load of $$.

This issue started happening after the mower was 6ft under water in a flood for 2 days...Kawasaki makes one tough engine,,thats for certain!!

Keep us posted bro.

Tom

Something that happens quite often in a piston powered engine is the rings align or become closely aligned that extra compression gets into the crankcase, thus the blowby is carrying liquids (engine oil) into the breather hose leading into the breather.

Bert is absolutely correct, disassembly of the block may bring about the rest of this story.

If you find the rings closely aligned then try the below:

If the rings are in good shape, nice and square, plenty of tension, cylinder is in good shape, place the rings at 180 degree away from each other. Begin at the bottom oil ring, then second compression, then first compression rings. Slide it back together and run the crap out of it because you probably found and fixed it.

I always wondered how rings stay in their proper clocked position after so many hours of run time...

Actually the rings do rotate some, but shouldn't rotate that much

Rings rotate a lot.

Place a piston on a rod vise. Take photos of a piston with your rings installed. Run the engine for ten minutes at WOT, drop the throttle and again WOT during this time. Give it several RPM run-ups. Disassemble and shoot a pic of the piston back in the rod vise and you'll find the rings aren't in the very same orientation. Same for all piston engines. Air (fuel) cooled, liquid cooled are all rotating their piston rings.

Done this on race tracks time and time again. Make a 4 second pass, tear down, change any parts hurt on the pass. If pistons and rings are good, move the ring gap back to maximum orientation and reinstall.

Had people take their engines home from our machine shop, run them hot and bring them back in for us to check out. Tear down shows the rings out of the alignment I personally always use for all engines. Always place the ring gaps at maximum orientation. 90 degrees is minimum, 180 degrees is maximum and most efficient for compression and least amount of oil consumption.

Reasons for running them hot varied. Too lean, too much time either in the crank or distributor, lack of cooling liquids, etc. Engines can't help human's stupidity. lol

With horizontal engines, gravity will try to rotate all of the ring gaps to the top as the gap is lighter than the ring.
I have not pulled all that many engines down but in most that I have the rings were between 11 and 2 ( clock positions )

Update on this issue. I replaced the head gasket. I took it out and started mowing. Ran great for about 30 minutes then all the sudden a sputter of the engine and a puff of blue smoke. Continued to do this about every 45 seconds or so. It seemed to be worse if the engine was under more of a load, like running through a patch of thicker grass or going up a hill. It didn't seem to do this at all if the PTO wasn't engaged.

I'm prepared to replace the rings, but obviously that's not a quick or easy job so I just want to be sure there isn't something simple that I'm overlooking that I should check first.

A side note to this discussion, I can understand if the rings are worn and that was causing this issue, but if the rings continuously move A LOT then this wouldn't seem to be an issue of the rings being all aligned, if so, they would soon move to another position and self correct. Either the rings don't move nearly as much as was described earlier, or my problem would not be an issue of ring alignment, in fact, nobody's would. Why would ring gap placement be so important, as we all know it is, if the rings were continuously moving that much?

with out trying to get into a mechanics diploma course, it goes like this.
Your rings do not seal against the cylinder wall because of their spring.
They get forced into the wall by cylinder gasses going through the gap, getting under the ring and pushing it into the wall.
If there is 200 psi on top of the piston, there is also 200 psi under the ring pushing it onto the wall creating the seal.
When you first install the rings they need help during the initial break in period because neither them , nor the actual bore are 100% round.
If the ring gaps are all in a line a lot of the compressing gas will simply blow down the line of holes.
They take months teaching mechanics exactly how this works and why this works which I am not going to try here so you will either have to believe me or go to some of the better piston ring sites and read their theory pages.

I wasn't doubting you Bert, the other post had me confused about rings moving around "a lot". I should have stayed out of your ring gap placement discussion anyway.

This post was about determining what is causing the intermittent smoking on my mower. Now that I've ruled out the head gasket, I just want to make sure I haven't overlooked something simpler before I replace the rings.

bert is correct. On our Hemis, we use what is called Dyke's rings. They are made in an L shape. There is little to no tension on the cylinder walls until valves are closed and on the compression stroke. Then they seal up like a locked box. That is how we put 1471 huffers on top of the heads as well as huge wiffles. Without them, you're not going to make upward of 6000 horsepower. Even with that ring, we still get about 4 gallons of fuel past the rings and out of the exhaust during a perfectly clean pass.

I appreciate that but it doesn't help.me at all toward resolving the problem I posted about. I don't have a hemi on my mower so most of that makes no sense to me at all.

I would do a leak down test before I tear down any engine,,not sure if you have the tools though.

Good advice, thanks. I don't have the tools but I know where to go. Thanks

I did a leak down test. The air in was running at 90 psi and the air going in held at 80 psi. No air sounding in the intake or exhaust. I could hear air going into the crankcase through the oil filler tube. I held my hand over the tube and felt very little pressure but could hear the air rush out when I removes my hand. From what I read a 10% reduction was acceptable.

I noticed my oil was pretty thin. I suspect some gas got into the oil before I replaced the carburetor. The oil did not smell strongly of gas and it would not ignite with a lighter but it was thin.

My exhaust valve was loose again so I reset it. I have had trouble with the valves loosening, not sure why.

I plan to put some frsh oil in it and see if that makes any difference.

Any suggestions?

My guess is possibly one or all of the rings but dont quote me on it,,just a guess.

I'm anxious to put the fresh oil in it. I'm hoping the thin oil was getting past the rings and building up in the valve cover. Any chance this could be the cause?

Oil that is too thin WHEN HOT will definately do that.
So you could start with new oil. New oil is always a good idea and neither hard nor expensive to do.
However I doubt it is the cause.
When I do leakdowns I usually go somewhere 150psi to 120psi.
The ides is to challenge the rings / valves.
At 80 psi you are at the lower limit acceptable compression pressures and in some engines will be insufficient pressure to cause ring sealing to occur.
Rings seal due to the action of compresses gasses getting behind them and forcing then onto the cylinder wall, not from their "Spring"

Yeah,I would throw some good old Shell Rotella 15/40 in it if it was mine....small engines love all that magnesium.

I went with the 15/40, no difference so I'm guessing the rings are going to have to be replaced. I was really hoping not to have to do a complete teardown! Question, when I replace the rings, is replacing the piston a must or only if I see a need?

Piston, rings, crankcase gasket and both seals is going to set me back about $150. I'm tempted to hold out and look for a twin cylinder air cooled Kawasaki and replace the whole engine.

arch252 said:

I went with the 15/40, no difference so I'm guessing the rings are going to have to be replaced. I was really hoping not to have to do a complete teardown! Question, when I replace the rings, is replacing the piston a must or only if I see a need?

Piston, rings, crankcase gasket and both seals is going to set me back about $150. I'm tempted to hold out and look for a twin cylinder air cooled Kawasaki and replace the whole engine.

Click to expand...

For me, the piston cost about the same as a full gasket kit and I never ever reuse an old gasket or apply silicone to an old gasket it is a no brainer to do the piston.
However do not order any parts till it is apart and you have checked the bore for ovality because new rings aint going to fix that.
The most critical measurement on your piston is the side gap between the ring and the ring groove.
Too big and it will leak past, too small and it wont pressureize.
After that is OK then check the wear on the thrust face and finally the play on the pin.
The latter two are not that critical on mower engines as they only spin at fairly low speeds.

Well keep us posted bro,,
I have had good luck with finding used engines on ebay or CL...I paid about $200 for a used FC 420V not long ago and its a great engine...most of the time they come out of home owner tractors with low hours on them.

Bert, I'm still struggling with this. I'm ready to accept that I need to replace the rings, BUT...

I ran the mower for about 30 minutes to get it warmed up. No smoke whatsoever and it ran fine. As soon as I saw the first puff of smoke I stopped the mower and removed the vent tube from the breather and stuck it in an empty coke can. I plugged the opening going into the breather. I ran the mower for about 20 more minutes. No smoke since the oil was going it the coke can and not the carb. I checked the can and in that short amount of time there was about 3 tablespoons of oil that had passed through the valve cover into the can.

If the problem were the rings, would the oil not be passing to the piston head and would the engine not be smoking like a freight train constantly?

Not to.mention the leak down test, albeit done at a lower psi than you would have done, indicated only about 10%

How does that much oil get forced up into the valve cover? There is no dislocation or residue buildup around the intake or exhaust valve guides so they do not appear to be bad, or at least bad enough to be allowing that much oil through.

I think I may have read enough to answer my own question. Oil is not coming up past the rings, combusted air is being forced down past the rings and building pressure in the crankcase, forcing the oil up into the valve cover past the reed valve. It's just taking mower about 30 minutes under load to build up enough pressure to start pushing oil out.

So... bad rings. Or bad cylinder.

Have I got it?

Did u replace the reed valve,,I never replaced mine just used a small reservoir to collect oil and dump it back in?
The reed valve should be pretty cheap I would think as long as its still available.

Pressure moving past the rings will always push compression into the pan, thus it is trying to escape thru the venting tube. One thing you can do to make an engine make both more torque and more horse power, not to mention easier revolutions per minute is to run your vent tube to the exhaust with an anti-blowback valve from a late 70s to early 90s Ford exhaust.

I began doing that in the mid eighties on my race engines and the dyno would show from 1 to 4 percent horsepower increase across the rpm ranges. Torque would increase on the bottom end (where a lawnmower engine operates) about 4 percent from 1750 to 5500 rpm. High end of the revs would make it up to low tens with the 3 inch stroke engines and upper nines with the 3 1/2 inch stroke engines.

That is huge numbers by only adding two valves and never used a new valve. Cost, free, adding a pair of 3/4 inch long 90 degree metal tubes, used materials, cost, free, 8 feet of 3/4 inch water hose, $2.40. Labor, what's that? We're going racing.

At any length, you can vent your valve cover to your exhaust which causes a low pressure (negative pressure) in the oil pan. It would take you a short time and a bit of fabrication and that would pay for itself in a short while.

If you have smoke after adding the venting system, you be got ring problems for sure. Follow all advice previously given by Bert for the freshen up and the venting system will be in place and paying you in gasoline savings.

How's that for learning some techie stuff on a Tuesday?

Wonder what would happen if you relocated that breather up higher than the air filter,,get a longer piece of hose and zip tie it up as high as you can and put a small fuel filter on the end of it....the pressure might not be enough to push the oil up that high...just an idea to keep ya cuttin thats all.

I checked the reed valve and set the gap at .003 per the service manual so i don't suspect that has anything to do with it.

I don't mid it being down, I have a backup, I just want to know what's wrong and make it right.

Yeah,I would like to know also,,I never found out what was wrong with mine,,it runs so good the way it is I just run it...I do know it started happening after the mower was 6ft under flooded river water for 24 hours..lol..these kawis are awesome engines!!!

You would have oil all over the place. lol

Yeah well if oil started pumping out that wouldnt be good..unless it was a harley,,you could put the hose above the chain drive and keep the chain oiled..lmao!!! JK

My '57 Panhead hardtail always leaked oil on the rear jug. It kept the chain lubed and my left pant leg soaked. lol

Yeah,,it was just marking its territory

What, if anything, is this an indication of?

Looks like oil burning on half of the combustion chamber part of the piston..ID like to see the head and the rest of the piston and rings too...complete tear down bro..lol
Hard for me to tell if its seeping past the rings or coming in from the top?

But we already know your smoke is coming from oil through breather so maybe its just showing us the spot where your intake valve is dumping/burning oil on top of piston too?

Yeah, I was really trying to avoid the tear down, but it wasn't bad once I finally accepted that it had to be done. That being caused by the burnt oil coming in through the intake would make complete sense. I attached photos of the head and rings. Keep in mind that I replaced that head gasket a few weeks ago and the head and piston were clean as a whistle. This is all how it looks after about 3 hours of run time.

I would be interested in seeing a ring sitting in the piston ring land for depth. Also, remove the valve springs and feel the movement in the guide with the valve stem. There is a lot of oil around the intake valve which can be guides and wear on the stem as well as pulling oil (pushing from bottom end pressure) up thru the breather (intake).

Slide a ring into the ring land, see how deep it sits inside the land. It should only sit about .002 to .008 deeper than the width of the ring itself. A mower motor may have more clearance, however, I don't remember it if it does. Hopefully Bert jumps in on the clearances soon.

Did you replace the intake valve stem seal ?
Did you clean the piston prior to fitting the new rings and in particular did you clean the ring grooves ?
They look very clean to me
The piston seals by gas getting under the ring and forcing it onto the bore.
In order to do this the side clearence and the rear clearence are critical .0005 too much side play and the rings can not seal.
Next question is what did the bore look like and did you hone it prior to fitting the rings ?
What oil did you use , rings have difficulty sealing when synthetic oil is used on brand new rings.
Was the piston fitted wet or dry.
Pistons should go in the engine dry, use little solvent like metho, to wet the bore just enough to get the rings in .
I refit them totally dry
Finally, never ever refit an old head gasket unless it is a copper one that you have annealed after you removed it.

I have not replaced the stem seals. I have cleaned the piston and it is clean in that photo. I can't get the new rings in until Wednesday so I haven't done any yet, just pull it apart. The cylinder is very nice nad smooth. I was debating about whether to hone it or not. That head gasket only has three hours on it so I was hoping to reuse it. It's the thin metal gasket.

Well if you put new rings in I would hone it a little,,the old bore is broke in to the old rings,,just a quick hone,Ive even dont it by hand with sand paper on small engines with great results,,just make sure to cross hatch it evenly.You should lap the valves and do the stem seals.

Tom,

Another way to do it is to take a wooden dowel if you don't own or have use of a hone. Cut a slit down the center of the wooden dowel the length of the width of your paper or emery cloth. Use a dowel as large as your hand drill will chuck up. Run the paper up and down fairly slowly until you get a cross hatch about 35 degrees down to 25 degrees.

Will get you up and running. If there is any ridge at the top of the bore, remove that ridge, then hone.

Saves your hand.

Yeah kinda like a flap hone..good idea...Ive only done it by hand on my stihl weed eater,,very small bore.

Get to a race track, find you left the hone and assortment of stones, you use what you can make on the spot.

Picked up a hone at Harbor Freight, honed the bore. Got the rings in today, put the rings in with the appropriate spacing. Put it in dry, filled it with Rotella 15W40. I had time tonight to get the engine mounted, I'll connect the pulleys and belts tomorrow and give it a start. Any suggestions on how I should first start it up?

hook every thing up fire up the engine throttle up & down a couple of times the engage the PTO and do the same thing.
If it will stay running strait into some grass,to load up the engine and open the throttle.
Whatever you do, don't leave it on low idle

Thanks Bert, good info. I probably would have left it at low idle

arch252 said:

Thanks Bert, good info. I probably would have left it at low idle

Click to expand...

Most do and that included me before I was shown the light.
I play with vintage motorcycles and some used to take hundreds of very smokey hours till the rings bedded in and 1 in 3 had to be done a second time after deglazing the bore.
This is because most of the time the carb had been adjusted to compensate for the worn bore.
On a rebuilt engine it is way too rich so I used to start the engine then spend 10-20 minutes adjusting the clutch followed by some careful running in.
New proceedure is start the bike with my riding gear on and as soon as it fires jump on & ride like I stole it around the block.
By the time I get back, ring are bedded in and the only smoke is black so I then lean out the carb. Worked perfectly every time.
So when I started doing small engines, I translated the same proceedure to them and it works a treat.
Rings go in dry so buy the time a good oil film has been created on the bore the dry ring on bore contact has worn the rings into the barrel enough to sustain full throttle and you need full throttle to get enough back pressure on the rings to finish the running in while mowing.

I was always taught to break em in how your gonna run them and I run them hard so...lol..I fire em up,,let the block get some heat in it then I run them hard,,especially two strokes.

Will be looking forward to your results

Glad you went with Rotella...thats some good stuff!

Tom

FWIW I break in engines with the cheapest supermarket oil I can get my hands on.
Reason being you don't want a lot of fancy addatives, all you need is a bit oil to stop things seizing as the the oil usually get changed very quickly.
The only thing to avoid is full synthetic oils which stick like the proverbal to a fluffly blanket so prevent the metal to metal you need to bed in the rings.

Well...rings are in, smoked a little at first but then cleared up after a couple of minutes. I started mowing and after running the mowe for about 30 minutes, big puff of smoke again, same as before. I guess there was no point in doing a leak down test if I was going to ignore the results. The leakdown test indicated the rings were fine, but I replaced them anyway. Oh well, I've now ruled out the head gasket and rings.

I noticed that my oil pressure switch light is now coming on rather frequently. It will come on for a second or two pretty regularly. Oil level is fine and there are no oil leaks.

Could I have a failing oil pump? Could that have anything to do with the problems I'm having?

My next step was to replace the entire head. I know where I can pick up a used one off a parts mower for cheap cheap. Cheaper than replacing any parts in the head or valves. I don't want to do that though if there's a chance my problem is with the oil pump.

Oh man,,well at least you will have a good engine for a long while when your done...lol

I have an old 73 Craftsman 16 HP single cylinder overhead valve Tecumseh and it had a fuel pump on it. For several years it would suddenly quit running and I found if I blow on the gas tank I could hear the bowl fill with gas. This summer I decided to take the fuel pump off and run it since the gas tank is slightly higher than the carb. Then I started noticing puddles of oil on the floor of the garage. The vent in the head doesn't go into the carb but just dumps out into the air and that is where the oil was coming from. I figured it was on it's last leg. Then I thought that maybe the port in the side of the crankcase that supplied the pump with pressure or vacuum or both had something to do with it so I plugged the port and the oil stopped. I assume you have a fuel pump on yours too so I'm wondering if you may have a leak in your crankcase somewhere or in the hose to your pump. It might be worth checking out.

Dana

Oil pump won't cause a puff of smoke unless it has stopped pumping or is bypassing and that is "not pumping". Only then will you see this elusive puff of smoke. When you tore it down, you'd also have seen a bad crankshaft, rod, cylinder walls, piston skirts and rings, not to mention the valves and guides would also be galded.

If you break the ceramic out of a spark plug, take an air tool adapter and put it into the broken spark plug and weld it together. Screw the new tool into the spark plug hole, place the air hose on it and that will spin the engine down to bottom dead center on that cylinder. Remove the valve spring retainer locks, then remove the springs. Check to see if you can wiggle the valve inside the guide. If it is really noticeable, you need to either replace the valve guide or valve or both. This is the time to replace the valve stem / guide seals regardless of the wear factor of your guides and valves.

Even if you're going to purchase the cheap, cheap, cheap heads, before you remove the current heads, replace the seals and see if your puff is gone.

The oil pressure switch may have gotten cracked and causing the oil pressure fluctuating if the oil pressure is about 40 to 65 pounds with a manual gauge at 3000 RPM. Beg, borrow or steal (ok, don't steal) a manual oil pressure gauge and check the pressure before you worry about doing the valve seals and guide/stem check.

You'll find the problem eventually,

Good luck,

Max

Thanks Max, this is a single cylinder, the model is FC540V. I don't think it has valve guides, I believe those are built in to the cylinder head and if they are worn the whole cylinder head has to be replaced. Please check that model yourself and let me know if I'm wrong about that. There are oil seals on the valve stems, I can check and replace those, about $8 for a pair. I can probably pick up the used cylinder head/valves/valve cover assembly for $20 or $30. I guess I hope it is the $8 valve guides, that will make me feel great about removing the engine, splitting the case and spending $100 on the piston rings, oil seal and crankcase gasket that I never needed!

By the way, I made a leak down tester and rather than use the broken spark plug trick I picked up a spark plug non fouler at the auto parts store, it has threaded female end so i used JB Weld to attach that to the smaller sized threaded male end of the air hose. It worked great and was super simple to make.

Yeah plugging up the fuel pump vacuum line and adding a 12v pump has always been an upgrade for me...coolness on the leak down tester,,great tool to have in your arsenal

The valve guides should press out and replacements back in. Even if not, run to your nearest auto machine shop and see if they don't have a pair of valve seals they can provide you they may have left over or purchase in bulk.

I used to add valve seals to folks engines where there weren't any. You can as well. Most shops won't charge you more than about a buck a piece for bulk supplied seals. A parts store will have opened gasket kits where they have split a kit to make up an order for a customer as well.

Have fun.

mechanic mark posted this in a thread earlier today.
http://www.briggsandstratton.com/eu/...m-solving-tips

click on troubleshooting-repair & type in smoking

this applies to all engines, not just B&S.

This was one of the causes of blue smoke: Also, be aware that any small air leak can cause an excess of air entering the crankcase and will create a higher oil mist than the breather is capable of handling. The excess oil will then return through the breather tube and back to the air filter.

The link is not working for me.

I have ordered the valve stem seals and they should be in tomorrow so by Thursday I should know whether that's made any difference. I have the used head on standby, I can pick it up for $35 and I'm pretty confident it is in good condition. Either way, it should allow me to determine if the problem is with the head/valves or some other issue.

arch252 said:

The link is not working for me.

Click to expand...

Cut and paste must not recover the entire link. Here it is from the web site.

http://www.briggsandstratton.com/eu/en/support/faqs/engine-problem-solving-tips This one only gets you part way to what you want to read

This is it, http://www.briggsandstratton.com/eu/en/support/faqs/engine-burns-oil-white-or-blue-smoke

I replaced the valve stem oil seals but it made no difference, no change. I picked up that used head, it was in very good condition. I cleaned it up very good, lapped the valves and put the new stem oil seals on it. Put it all back together and started it up. It runs great but I didn't have time to mow long enough to see if that fixed the problem. It won't start to smoke until it's been running for about 30 minutes. Hopefully I will be able to run it this weekend and can give an update. If the problem if fixed then it was obviously the valve guides. I'll update when I know and hopefully then we can put this thread to rest. I'm quite sure you all have had enough of this one. This sure has been a learning experience for me though and I can't tell you all how much I appreciate your input and advice.

Unfortunately I am about to start a new thread on the Kohler page. If I get banned from this site I will completely understand!

No body gets banned unless they are constantly breaking forum rules, being nasty, abusive , profane , using the forum to advertise or writing things that could be libalous.

If you have a separate problem you should always start a new post.
One problem one post actually works best and keeps things simple & easy to follow.
What gets people cranky is putting the same post on mutiple sub forums.
There is only one forum.
It is broken up into specialist sections to make it easy to navigate.
The more problems you present the more solutions that get found the more useful the forum becomes and the more we all learn.

Wow,,that is one of the reasons I left mine the way it was,I had a funny feeling it was going to be a PITA to figure out,,it runs fine just dumping excess into a small container for now..lol
This site is about helping others and I think we all did a great job,,you did a super fine job working on that engine,,and I am looking forward to the krawler I mean Kohler thread.

Tom

I know this will come as a huge disappointment to many people but we can now put this thread to rest.

Ran the mower yesterday for a long time, no issues at all. The problem was undoubtedly the valve stem seals that are pressed into the cylinder head. They were worn and allowing air to be pushed into the crankcase causing excessive pressure buildup in the crankcase resulting in oil being forced from the crankcase up into the valve cover breather and through the rubber vent tube into the air cleaner then into the carb where it was sucked into the intake and the oil was burning in spurts in the combustion chamber causing intermittent puffs of blue smoke from the exhaust. The leak in the seals was so slight the mower had to run for about 30 minutes before enough pressure built up to cause the problem to start, so for the first 30 minutes it ran like a champ.

I know this thread has been a pain but I appreciate everyone who hung in there to help me diagnose and fix this problem.

arch252 said:

I know this will come as a huge disappointment to many people but we can now put this thread to rest.

Ran the mower yesterday for a long time, no issues at all. The problem was undoubtedly the valve stem seals that are pressed into the cylinder head. They were worn and allowing air to be pushed into the crankcase causing excessive pressure buildup in the crankcase resulting in oil being forced from the crankcase up into the valve cover breather and through the rubber vent tube into the air cleaner then into the carb where it was sucked into the intake and the oil was burning in spurts in the combustion chamber causing intermittent puffs of blue smoke from the exhaust. The leak in the seals was so slight the mower had to run for about 30 minutes before enough pressure built up to cause the problem to start, so for the first 30 minutes it ran like a champ.

I know this thread has been a pain but I appreciate everyone who hung in there to help me diagnose and fix this problem.

Click to expand...

Good old valve job solved it huh.
Glad you figured it out,sometimes you have to shotgun parts before you find the culprit.

No worries on the thread,I actually really enjoyed the journey myself.

Tom