Pretty please, do not purchase one of those aftermarket Chinese carbs off Amazon, it won't run right. Purchase the OEM carb and solve the problem correctly. They are not expensive. Get the model number off the machine and got to Partstree.com and get the part number for the carb. If you provide me with the model number (it may be under the bagger cover and it is either silver or white or on the rear of the chassis behind the engine). That looks like a Briggs engine?, so probably a plastic carburetor. Alternatively, take the carb to a small engine shop and have it cleaned. They are very simple carbs to clean as there is no low-speed circuit. Simply remove the two screws holding the bowl on, clray some carb cleaner through the brass main jet, remove the pin from the float and spray carb cleaner into the inlet seat, put it back together and pop it back on. Here is a YouTube video with instructions.Yeah so the choke opened slowly but it definitely did open fully.
I have had a few engines over the years that ran rough, and with some seafoam treatment over the long term, they would clear up and run well again. But the plan is to get this thing running good and sell it. I don't have time to mow with it all summer. So I'll probably just do the carb. I also have very bad luck taking carbs apart. So if they're only $20 on ebay, I'll probably just replace it. I know many people don't like ebay carbs but I've had very good luck with them. Very few duds.
Seafoam makes people feel better, like they did something, the majority of the time. However, usually is not the solution or even marginally helpful. It is always better to keep OEM carburetor and clean first before buying an aftermarket carburetor. That said, I have had great results with most aftermarket carburetors I have purchased.Ok I've now mowed my lawn twice with this mower, and its a pretty big yard for a small push machine like this. No change in sputtering/misfiring at all even with all the seafoam I ran through it. I even ran it dry then did a little more mowing with just clean, straight gas, incase I was overdoing it with the seafoam. Nada.
So I'll be replacing the carb and I bet it runs perfectly after that.
If Seafoam were that good, why am I wasting my time cleaning all these hundreds of carburetors over the years and having the engines run great afterwards? Before I started running a small engine shop, I thought Seafoam was the bomb too.I have to disagree on the effectiveness of seafoam. It doesn't always solve the problems but it has helped a lot more engines for me than it has done nothing for. Two mows isn't a very long treatment but because I need to sell this mower and finish it's video, I really don't have time to mow with it all summer to see if it works, especially when new carbs are $10 shipped. But I've had very good luck with sea foam actually DOING stuff, and by stuff, I mean making engines that run a little rough, run like they should.
Good luck creating a proper running machine with the ten-dollar bill. Simply remove the carburetor and clean it thoroughly. It's an uncomplicated process, and you can Watch YouTube videos for guidance on cleaning. Allocate 30 minutes to fix the problem.Because you don't have time to use a customers machine for a few weeks to let seafoam work its magic. But as a homeowner, I have that time.
Also I'm not against cleaning a carb. Well, I am but not like that. Why bother cleaning when a new one is $10. But I'm just saying, it doesn't always fix things but it often will if you use it regularly. I put an ounce per gallon into all my power tool gas and I've had a lot fewer carb issues since I started doing that.
But yeah my boat has 3 carbs and they seem to have bad needle valves that let too much fuel in causing stalling at idle and a smokey mess when you are going slow. Seafoam isn't going to fix that.
At no point have you checked high end RPMs. Low RPMs will result in surging, especially when the carb may have a blocked passage way.
Let me spell it out in simple language. Either your carburetor is dirty and needs attention, or much less likely, you have an air leak. Try to open yourself up to people that have years of experience and are trying to help you. When I get phone calls from new customers, I have noticed that it is not uncommon that people are poor listeners. If you can get the mower running correctly, the sense of accomplishment is worth the trouble.Ok well i disagree with some of what you say, but this part I don't understand at all:
I don't know what you mean here or what you are suggesting I do?
It seems very likely that OEM carburetor is dirty, and that the aftermarket carburetor is not dead on with air/fuel mixture, so not running properly.Doesn't it seem unlikely that the original carb was dirty, and the brand new one is also dirty? Seems like in this scenario where I've gone through two carbs, the air leak would be the more likely problem, no?
EDIT: First, I apologize that I wrote my earlier comment w/o watching your entire video. As a consequence of that, I missed the fact that in addition to SURGING, your mower actually is MISFIRING as well, albeit intermittently.Ok well i disagree with some of what you say, but this part I don't understand at all:
I don't know what you mean here or what you are suggesting I do?
No. There is a comment in ALL mower manuals about removing carbon say every 5 years. Check your maintenance items out in your manual. Clean cooling fins and some de-carbon action are highly over looked. Carbon will not work itself out. Once you de-carbon one you will get your answer. Most have big chunks of carbon say behind valves and well all over the chamber.If there is carbon on the valves, will it work itself out if I just keep using the machine?
Doubtful. I don't recall... have you checked the flywheel key? Backfiring would make me suspect the key.Yup I cleaned the carb the other day, took it all apart, sprayed everything. The tank looks totally clean and has seen several tanks of fresh gas so theres no old fuel anywhere.
Would a dirty carb cause backfiring out the exhaust?
Hand driver is plenty tight. Make sure the rocker stud is tight and thread locked in. You don't need NASCAR torque on any of these tiny bolts/nuts.So it felt like the set screws had loosened up a lot, even though I had tightened them good and snug with my T10. I re-tighten them after I readjusted them, squeezing as hard as I could with my T10 driver but no luck. Is there a trick to this? The first T10 (bit) I used snapped when I was trying to initially loosen them. I can't get them back that tight, not with my hand driver anyway.
Might have residual fuel in the chamber lighting off. Nothing to worry about.Another thing I don't udnerstand. I was able to pull the cord and get the machine to fire a few times before it died again.
If the intake vale is stuck closed because the rocker isn't touching it, how was the engine able to run at all? That doesn't make sense to me?
Do you mean valve cover? If so the valve cover doesn't hold anything on other than itself and or maybe a gasket.The rocker issue was just because I took the engine over off and didn't realize that removed the pressure holding the rocker on to the rods.
You need to FLUSH, BLOW and reverse blow the tank out. If you have a 90 degree hose barb on the tank outlet, make sure you have flow there as in a good solid stream. Be looking at where you can't see inside the tank. Not just in the bottom and call it good.So I'm just going to drain the fuel tank again, remove and clean the carb again, and see what happens. The fuel tank looked plenty clean to me, but maybe since it will be empty anyway, I'll clean it with some soapy water.
Not advised. Any grit being smaller than you and I can see will go right back in where you don't want it to.Then I'm going to put the same fuel back in. That fuel is not old, it's new. But its been in a tank that theoretically could be dirty. So it could have some dirt in it. SOOO whats a good say to strain the fuel, as a precaution? Like a coffee filter maybe? Something like that?
Not needed but not critical. Remember to use some alcohol to clean that connector when you are done testing. Remove the adhesive from the tape. It will attract grit and grime.I put a little electrical tape on the coil side connector to make sure it doesn't try to arc over to the engine block.
IF the coil is good, the engine will run against the flywheel brake. You will need to strap the deadman lever to the bar leaving the engine running, for testing only. Should run the tank dry IF the coil is good.what exactly will happen when I let go of the man lever?
You need to verify you have solid spark all the time you are holding the deadman lever to the bar. With a good coil, should of ran perfect IF it was a spark issue. You could have a partial failure in your ignition coil? Never seen one but it is an electrical part. Coil gets hot and starts sputtering???????? Did you remove the coil polishing the mounting pads and such? Coil needs a good ground.I unplugged the coil's ground line and started it up, no change in behavior.
So your word is misfire. Back to the coil again. Get one of these. The Oppama PET-4000 is supreme. You need to rule out SPARK as a cause.Its one misfire every 1 to 3 seconds on average. It didn't seem to be getting worse,
Could be a bad coil. You are not testing anything as discussed above. Could be a Chinese clone slash black market spark plug causing all of this. You will never know as you don't test anything.Ok I just replaced the ignition coil and still NO change in behavior.
Might take more cleaning. You need to search for vacuum leaks while you are testing.cleaned the carburetor 3 times
Cleaned like a new one? As in zero trash or any 90 degree hose fittings on the bottom packed with dirt and grass?cleaned the fuel tank
Needs tested. Doesn't mean it will fire under compression.replaced the spark plug
Have to take your word on it. Could of fouled something up. I do it all the time as I am an idiot.gapped the valves
OEM Briggs carb or a Chinese Gambler Series from Scamazon or Fleabay?I also replaced the carb with a new one. The new one had starting problems but once it would run, the engine had the exact same misfiring
I hope you don't mean dumping it off on someone else. Better disclose it doesn't run proper in bold letters. People like that I tend to dislike. No place for them in my "try to be honest" world.At this point I might just sell it as is and call it done. What a frustrating project!
Your last video, to me, sounds like the governor spring is/could be fouled up. Sounds like the revs are bouncing around. Hold the throttle plate lever with your finger on top of the carb. See if the revs smooth out. Report back. And don't buy any new parts LOL.
Also verify the choke plate is wide open once warmed up.
Yeah its misfiring about once every second or so, but the mic on my phone doesn't really pick up the miss. It works well, it cuts well. I don't have any SUPER thick grass but in the thickest grass I have, its good. I did try partially covering the intake last time I used it, it had no effect on the rpm/misfiring. I've had the cover off of this thing like a dozen different times this year, the cool finds are definitely clean. I used a piece of junk mail to space the coil, it is suuuper close but not rubbing.Watched your latest video again. Not hearing anything out of the norm for that engine. Maybe the governor spring is bad causing the slight stumble?? Hold your finger on the throttle linkage. See if she smooths out. Or put cardboard over carb inlet giving a slight choke effect. Something has to smooth her out. Bad plug, maybe it was dropped or counterfeit fake news black market?
very mow. De carbonizing the cylinder and valves. Check head bolt torque yearly.
Nope. She runs at say 3600 until she needs more fuel/air slash engine load. Governor system opens throttle in attempt to keep revs at 3600.I was under the impression that these engines operate at wide open throttle?
So I have been thinking that the misfiring (again, the misfiring that you really can't hear on these videos but is definitely there) was causing the changes in RPM. But maybe the problem is all governor related, and maybe its the opposite, the changes in RPM are causing the slight misfires?
Anyway heres the video and me poking around with it:
Is the governor/throttle linkage supposed to be that.... twitchy?
But it will outlast all the new battery mowers out there x10.There are 9 pages of posts about this mower that is worth about $100 bucks. If it is running good e
Nine pages on a push mower. Isn’t it good enough at this point?
So choking down roughly 50 percent did nothing to smooth her out. That tells me the main jet or circuit might be clogged. Next test, choke it all the way closed like you just did in the last video. You should hear it stumble down in revs. If max choke does not stumble, confirms main circuit is clogged.
Make a new video. While running, hold choke plate closed. Let's confirm this. Show it like you did in the last video. We should see stumble city. Go from choke open to slowly closed.
Next hold throttle plate slash linkage steady. Looking for steady revs taking the governor out of play for testing only. Do a low rev and a high normal rev condition.
Okay this is getting crazy. The main still sounds partially clogged. It does give a little more fuel and less air when choked down. Slightly smoothing out the engine. I hope you fully choked it down.Choking down didn't seem to affect the RPMs but I feel like it did smooth out the misfiring a bit. It's hard to tell, and none of it is picked up on the camera. But I don't know, it did feel a little smoother.
Looking at the top of the carb. There is a choke plate which is physically away from the engine block and there is a throttle plate which is closest to the block ON/inside the carb body. That gov spring with a lot of coils is your throttle/governor spring. You have a rigid linkage from that thermostatic lever that controls the choke plate. Thermostatic lever heats up off the exhaust and moves the choke lever choking the engine down. This increases the air velocity which picks up more fuel off the main jet and its circuit. That enrichens the engine when cold to make her start. Colder air needs more fuel. Cars and trucks use more fuel in the winter. Fuel is not as volatile and so on. That is why we have summer and winter blended fuels. Getting off point."throttle plate slash linkage" . . . that what now
I meant hold the throttle linkage on top of the carb steady as in not moving it. If the revs and or misfires steady out, need to look at the governor spring, maybe the governor arm setting on the outside of the block or the internal governor itself. Low revs meaning say 2000rpm. High revs at 3600 full song. Does it smooth out?Also not clear on what you're actually telling me to do when you say "Do a low rev and a high normal rev condition" ??
Well that was bad timing. If you don't already know. For road rash the trick is anti-bacterial cream like neosporin ointment and honey 50/50 mix. Slather it on and wrap in clear Saran Wrap plastic wrap kitchen stuff. Tape it all down. Be surprised how fast it heals compared to all other methods. Honey is anti-bacterial, fungal and so on.Also note, I crashed my mountain bike yesterday and messed up my hand pretty bad so it may be a few days before I'm able to do any of this.
I got that. You wouldn't be here unless there was an issue. I'm sure you have other pressing issues like NOT CRASHING YOUR BIKE you silly goose.ALSO, second note, all forum posts are optional. You can skip any you don't like, for any reason, no questions asked. As for "isn't 9 pages enough", obviously not if the machine isn't 100% fixed yet.
Sometimes good enough is good enough. Good luck.This is to the OP. If you understood how the fuel, ignition and compression systems work together on a small engine, this thread would have ended 60 posts ago. Reading what you are posting the techs on this forum can see that by not even knowing the names of the components or how that work by themselves and in conjunction with other components tells us your expertise on this subject is very minimal and you are looking for someone to hold your hand and solve your problem. Maybe you should reread post #25. You are so closed minded and your assumptions are absolutely correct, you won’t listen to suggestions given or think that maybe you are wrong. You claim that your $1000.00 phone can’t produce a good audio, as an excuse for us not being able to help you. Did you ever think that your 100% is not achievable on a $50.00 engine? Yes that is what it cost MTD to purchase that engin, and Briggs still made a profit. It’s time you put your ego and false expectations on the back burner and realize your assumptions on how a perfect small engine should run is not achievable.
Okay this is getting crazy. The main still sounds partially clogged. It does give a little more fuel and less air when choked down. Slightly smoothing out the engine. I hope you fully choked it down.
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Disconnect that rigid choke linkage for testing. That rigid piece of wire that connects to the choke. Manipulate the choke plate with your fingers a lit easier. Should stumble down in revs and make some black some out of the muffler.Then I fully closed the choke. The only way to do that on this carb is to first flip the throttle to wide open, so I did that real quick and then closed the choke fully. You can see that in the video. It ran poor but it didn't conk out.
IF it is the head gasket, it can have a gasket leak that gets into the push rod tunnel that goes back to the cam and oil sump. From the oil sump out the block breather hose inside the air filter housing. So head gasket to cam tunnel then oil sump. Oil sump to block breather and breather hose that connects to the air filter for reburns.How would a bad head gasket cause blow by out of the crank vent? Wouldn't the hot gasses still have to get by the piston rings to get in to the crank case?