Case 222 lawn tractor problems

[briansgi]

I have a Case 222 lawn tractor I bought in 1983 brand new. It has the Kohler 12 HP motor. My problem is after I mow for about 15 minutes it will start bogging down and then die. You can start it right back up again and after a few minutes it does the same thing. I've took it to 2 different mower places and this is what has been done and nothing has fixed it.

New carb installed
New coil
New condensor
New points (and adjusted properly)
New gas cap (thinking clogged vent line)
Adjusted timing
New spark plug

I'm at a loss and so are the shops that have worked on it. I've yet to take it to a Case dealer, I did call one and told them everything it was doing and everything that has been replaced and he said it could be something in the motor, possibly a valve issue. It's definitely heat related, but once it starts having this problem, it takes only a minute or 2 to do it again. It also seems to run better when the mower is not engaged, so if there is a load on the mower, it's alot worse. I've got a schematic of the electrical and I noticed there is a solenoid, rectifier and an alternator. Could either of these electrical components be causing this? Does anyone think it's actually in the head of the motor causing this? When it starts to die, I can quickly disengage the mower, throw the choke on and sometimes that prevents it from dying, but not always. The fuel has been dumped, tank's been cleaned, new fuel line installed, etc. I'm at a loss!!

[Smalltimer1]

Have you ever rebuilt the engine? That may be a sign that its getting tired. I'd have a look at the head gasket as well as the valve seats.

[briansgi]

Motor was rebuilt probably 7 years ago by a local good ole boy. What in the motor could be causing this? A stuck valve or something? And if that's the case, any way of checking that's the problem before the motor gets tore down and rebuilt?

[Jman]

I would have the valves cleaned and ground. Normally on an old Kohler like that they will build up with carbon deposits on the exhaust valve stem. They will get hot, stick open, and the engine will die. Normally you will hear a very distinct sharp metallic "click" and the engine will start right back up and run a short amount of time. The valve and guides need to be cleaned.

[briansgi]

Ok, sounds like that may be it. I dropped the mower off the other day with a guy who's been working on these for a long long time. He seems to know what he's doing. He was going to test/replace the fuel pump, thinking it might be going bad.

I'll tell him what you said about the exhaust valve. I did mention to him maybe it could be a valve, he didn't think that would be it but I'll let him know advice here would suggest that may be it.

So far I've spent over $300 on this thing from another shop and nothing's been fixed. They charged me for a new carburator which didn't solve anything!! I've also bought a new coil, points and condensor too.

I'll let you know what ends up fixing it! Thanks again!

[briansgi]

Finally someone found the problem with my mower. Apparently there is a fuel filter inside the gas tank! It was clogged or partially clogged and replacing it solved the problem.

The mechanic had no idea there was a fuel filter inside the tank!!

[CCWKen]

Originally Posted by briansgi

Finally someone found the problem with my mower. Apparently there is a fuel filter inside the gas tank! It was clogged or partially clogged and replacing it solved the problem.

The mechanic had no idea there was a fuel filter inside the tank!!

It's probably a "screen filter". I hope the tank was flushed out or you'll be having the same problem soon.

[briansgi]

He showed me the filter, it was not a screen type filter. It was brown and very small, kind of looked like a grinding wheel you would see for a dremel tool.