Maybe a valve adjustment needed..?? How old is the tractor..?

 

It's old. I'm pretty sure these were manufactured back in '95.

The weird thing is.....the mower was running relatively fine after I picked it up from my buddy. It mowed my front rear lawn (like .6 of an acre) and then started acting funny.

If it was a valve adjustment/replacement......is that something a relatively handy guy can do. I've done a lot on vehicles, just never really have torn down an engine to work internally.

 

There are some amazing videos on YouTube, may take some time, but you should be able to find a valve adjustment video for your engine.

Mike

 

I'd get a spark tester and check the QUALITY of spark. You may have a weak coil.

 

Thanks for the responses guys.

In reference to the valve adjustment, does that usually require removing them? At that point, would it just be easier to get a new exhaust and intake valve and replace them?

Bill - I have taken the spark plug out and reconnected it, and tried starting it while holding it to the block and the spark looks fine. Is there something else I should do? Also, when you say coil, are you referencing the alternator?

 

QUOTE:"Now that that is installed, it's still running rough and backfiring, and sometimes dying after a few minutes."

Key is 'after a few minutes'.
Does it run well until it acts up? If so, one would think that the valves are functional, but may need adjustment as the parts expand when they heat up, changing the clearance.
It is also possible that there's a fuel flow restriction, that allow fuel to fill the float bowl fully, but after the engine starts and runs for a bit, it is using more fuel than is flowing, so the level falls in the bowl over time until it becomes too lean to run.
After it has been run for a while, and is starting to act up, you could drop the float bowl and catch the fuel contained inside. Compare that volume to the normal 'full' volume after it has rested for a while. If there is a difference, you have a fuel flow problem, possibly material inside the tank gathering at the outlet and slowing the flow.
The backfire is sometimes a symptom of 'lean' codition. I never figured out why, it just is that way. If you are lacking fuel as above, you'd get lean condition, possibly causing backfire. If the intake valve were sticky, or was adjusted too close, so it did not close tightly, it could cause backfire. Enough to keep you busy for a couple hours?
tom

 

Thanks Tom.

The "after a few minutes" is with it running fairly rough. After I got the new Carb on, it started up and would get running, but would be fairly rough, and both sitting/test driving (a circle around the lawn) it ran rough and almost died a few times until I engaged the clutch to let it catch back up.

Overall, it is rather sporadic. It will always start using the choke, and then moving it to "fast", but it usually takes a few start ups to finally get it to stay running. Then when its running, it is rough, backfiring randomly, and then eventually dying or coming **** near close to dying before I cut the engine.

I've checked the fuel flow, and it appears to be good. The fuel filter is clear, so I can see gas flowing thru. I also know the bowl is filling becuase I can push the little release on the bottom of the bowl and have fuel flow out.

One other symptom is that I can no longer put it in the "slow" throttle setting. If I do, the engine dies.

 

I've had coils that would break down and not spark for a few seconds, fill the cylinder with gas mix, the fire and backfire like a gunshot.

 

So, forgive me for the "stupid question" but the coil on a lawn mower is the same as the alternator, correct? Or are we referencing something different?

When I search for coil in the parts manual online, the only thing that comes up is the alternator (apart from some bushings).

 

I know you said new plugs, but it is possible those new plugs got flooded at some point and are now marginal. Try a new set of NGK plugs.

Backfiring is usually an intermittent ignition issue. Also check out the Operator Presence safety circuit.

 

I've actually replaced the spark plug twice. Replaced it once before the carb replacement, and then replaced after the new carb was installed.

The one I currently have in there is one of those E3 spark plugs. That wouldn't be the source of one of the issues would it?

 

It would seem some engines are sensitive to the brand of plug used. I have never used the E3 plugs but have stuck with Champion for the Lawnboys. A cheap test, but I would put in whatever brand of plug the manual calls for. Good luck! Bill

 

I have never had any luck with E-3s and if anything they do not work as well as the factory plugs. The only reason I bought 2 were they were on close out and I can see why they were closing them out. Roger

 

Thanks for the heads up guys. I picked one up because it was on sale.

I'm heading to HD after work, so I'll be sure to pick up the factory spark plugs, which show as Champion J19LMs.

 

bad gas can do the same as all you have said also

john

 

Thanks for the feedback guys, Gas is brand new.....just got it from the pump yesterday.

 

anyone translate the 143. number into I assume tecumseh? number. lot of discussion on valves. is it ohv or lhead?
edit: appears to be TVM220-157255E lhead.

 

I also do not like the E3 or any specialty plugs. Just the standard champions Run the best in Briggs and Stratton and Kohler engines. I'm okay with the NGK and The Hondas. The new Eco plug Champion makes is fine too and probably a little bit better but basically it is just a smaller wire probably Platinum tip plug.
The coil is not the alternator they're referring to. Coil, Magneto, ignition module are all interchangeable terms basically. The alternator is also referred to as the stator that is typically under the flywheel on a riding mower engine. The coils of wire on the stator sit there and the flywheel which has magnets underneath it spin around it to create the current to charge the battery. There are a few smaller walk behind push mowers with 6 horsepower or less that have a charging system. This is usually a small half the size of the coil, coil of wire that sits outside the flywheel that is used to create current from the spinning magnets.
Most of these create ac power which is what you get from spinning magnets over the coils of wire, then they either use an inline diode or a voltage regulator to turn into DC to put into the battery.

 

My engine translates to the following: 143.951010 -> TVM220-157255E.

 

Update: swapped out the spark plug back to the champion brand plug, still acting the same.

First few start attempts, briefly fires only to die within seconds. 4-5 tries later....it fires up, gets going, backfires and dies.

 

check for a sheared flywheel key. not common on riders but I have sheared two of them by cranking when hydrolocked from flooding gas into cylinder.

 

i was gonna say check this - also check your seat safety switch / clutch safety switch.

 

sounds like the fuel shut off is not working as in not opening

john

 

Get a spray bottle and see if it keeps running if you spray gas into carb. Sounds like you're not getting fuel through main jet.

 

Would there even be a fuel shut off on this?

Its a gravity fed fuel tank with a fuel line to the carb.

 

Most of them do not have a fuel shut off from the factory. They're more than likely though there is a solenoid on the bottom of the carburetor that has 12 volts going to it when the key is in the on position to keep it open to allow fuel to flow into the main jet on the carb.
. You should be able to hear it and or feel it when you click the key on and off as it clicks open and close.

 

If the carburetor is new, I would suspect electrical, like coil. I've had to replace the coil once and due to poor installation, the backfire was occurring so I reinstalled following recommendation from this forum and the backfire is gone. Now it occasionally back fires only on engine shut off. This I believe is the faulty solenoid that is right under the carburetor bowl. But this I can live with.

 

Your carburetor does not look like it is new.