OT - Lawn Tractor Puffing Out Intake

OK...

Background - Kohler Courage 22HP, (SV-620), ran out of gas mowing. Left it sit for a few days until I got back to it. Unfortunately had our only rain storm of the last month while the tractor was out in the yard. Got some gas and filled it up, started and ran fine with good power for a minute or so, started coughing/losing power and died. Didn't make any extra noises. Seems like probably water in gas, besides the rain (which really shouldn't have entered the fuel system) the temps had changed pretty drastically and the empty tank probably had a pretty good chance for condensing water out of the air.

Drained some fuel from both the tank and the carb, replaced fuel and air filters. Engine won't even give the slightest hint of starting. Spins fine until I need to charge the battery. I pulled the plug and it has spark, replaced it as well.

Am noticing as I spin it with the cowl off that it is actually blowing a little air out the intake. That doesn't seem right to me. Amount is pretty small. Anyway, looking for a little help trouble shooting this (And hoping I'm not looking for a new mower).

Thanks in advance,

Kirk

stuck valve or dislodged valve seat ? bill

That is the classic sign of a valve problem , but believe it or not I had a Briggs engine doing that and for some weird reason a NEW spark plug fixed it. I still can't believe it myself !
Might want to check the flywheel key too.

Sounds like you may have a piece of carbon caught in the intake valve.

You mentioned the possibility of condensation. Possibly a stuck valve from condensation?

Anyway, the first thing I'd do would be pull the valve covers and check valve operation.

As the engine is running out of gas the fuel mixture gets leaner and leaner and this will make the cylinder heat up,it may have gotten hot enough to pop the valve seat loose on the intake or warped the valve.

Pull the plug out and put your finger in the hole and spin it over. That will tell you if you have lost compression due to a stuck valve. If no or little compression pour some ATF in the cylinder and spin it over to coat every thing and let ti sit a day or so. Then try it again. If your lucky that will free things up. If not you may have to pull the head and have a look see.

I had the same problem with an old Wisconsin engine on a Ditch Witch. After some searching I discovered that there was no Clearance on the intake valve. A simple valve adjustment caused the engine to start easier, run cooler, make more power and ended "reversion". HTH Sam.

I had a similar thing happen on my Kohler KT17 last month. Two of the air cleaner mounting screws had vibrated out and one was stuck in one of the intake valves preventing it from closing. I took the intake manifold off and was able to fish it out with a wire with a hook on it.

Dump some oil in the spark plug hole and turn the engine over. If it is a flathead engine with a vertical cylinder you should be able to get some oil down the valve stems, which is probably where your problem lies. If it's overhead valve, you might try a trick used on aircraft engines: stuff a bunch of cotton rope into the spark plug hole, then turn the engine over on the compression stroke until the piston bumps into the rope, pushing the valves closed.