22 kohler problem

[steveair]

hello,

I have a toro dingo with a 22 kohler with about 230 hrs. . While plowing yesterday, it decided to start acting up on me.

The symptoms are this:

It starts up a little harder than usual, but nothing out of the norm for cold weather.

It runs good for about 5 minutes, then just started to die. After about 10 minutes, it just about stalled out, so I shut it down.

When I restarted it about an hour later, it ran fine for about 20 minutes, then started acting up again.

When it starts running bad, it seems to be missing and also is puffing a lot of black smoke (not blue).

I plan on changing the fuel filter again, the plugs, and the air filter, but besides that, I'm not too familiar. I've read some previous posts, and have gotten some ideas, but just want to try and get a few more before I get too involved.

Another problem that it has had is backfiring. I've tried every trick I've learned here (letting it cool down, turning it off at high rpm, etc) and yet it still backfires all the time. When it was running bad, I swear it backfired once or twice while running.

Anyhelp greatly appreciated.

steve

[sdwally]

Two things I could think of off the top of my head are:
1) When it dies next time check to see if you are getting spark. If not it could be a bad condensor, coil starting to go bad, and/or cracked plug wires(doubt plug wires at 230hrs).
2) Valve lash needs to be adjusted. It takes about 100 hrs to settle into their normal operating postion. This will change the valve lash set at the factory. Valve lash is easy to check and adjust. I'm not positive but, the intake should be about 0.007" and exhast about 0.011". Normally it will be the exhaust valve that is off.

[Fish]

It is safe to assume you have a Kohler Command, so the lifters
are hydraulic[No adjustment], and it does not have points or
condenser. It may have a device called Smartspark, but I would
focus on water/junk in the carb, costs nothing to check. Just
remove the nut and drop the bowl off of the bottom of the carb
and look inside. Do this and check back in with you engine model
numbers and we can go from there.
Fish

[Richard Martin]

The backfire while running is a symptom of an ignition problem. It sounds like a coil is going bad. Although it may have water in the fuel this is not usually associated with backfiring.

[Fish]

Backfiring when the engine is shut down is due to unburnt
fuel exploding in the muffler.
Fish

[Richard Martin]

Fish,
My diagnosis of his problem was based on everything he said he was experiencing. I am well aware of the "backfire while shutting off" problem that Kohlers have but he also added this

"When it was running bad, I swear it backfired once or twice while running".

When an engine is running and it backfires it is usually associated with the ignition turning off and and then back on for some reason. He also said that the engine would run worse the longer it runs.

"It runs good for about 5 minutes, then just started to die. After about 10 minutes, it just about stalled out, so I shut it down.

When I restarted it about an hour later, it ran fine for about 20 minutes, then started acting up again."

This is exactly the type of symptom you would get with a coil that is going bad.

[Mowingman]

I lived with that same problem on a Kohler 22hp on and off for over a year. I kept thinking it was a fuel problem, but it turned out to be a bad coil. Mine would skip a beat and backfire once in a while when engine was loaded up good in heavy mowing. I bet it's a coil problem.

[Fish]

I am just a little shy to tell someone to run out and spend a lot
of money for something that may or may not be the problem. Checking for dirt and water in the carb bowl costs nothing, and
does not take that long to pull a carb apart. If it looked clean
and the bowl area was not low on fuel[indicating a fuel pump
problem], I would suggest new plugs and air filter. Also the
presence of an oil sentry unit could be the problem area.
Also a chafed wire to a safety switch grounding out on the
mower frame could give similar symptoms. There are many
things that could cause these problems, and replacing an
expensive ignition module {or in this case modules} might be
wasting good money. I am not trying to fight but fix this guys
problem without wasting money. I could go on with more possible
causes with this mower, but without more sound input from the
original poster it would be wild guesses. I am not trying to argue
but be helpful, sorry if I came across as arguementative.
Fish

[khouse]

An engine can have a lean missfire also while running. As far as it backfiring on shut down - try shutting the engine down at full throttle. This is how my 25 Command has to be shut down as not to blow the muffler clear off the engine. I would check the carb also first. These command carbs are touchy. I had to replace the complete carb on mine to finally get it to stop surging. The old carb was clean as a whistle - but I couldn't soak and blow the problem out. You may have some water in the bowl as Fish has stated. Takes 5 minutes to see. This can also be a smart spark problem as stated above also. These problems are hard to find unless it just dies completely. I had a customer with a Grasshopper complaining about his motor backfiring once in a while. I never once got it to do it with me. So at his house I asked him to try to make it backfire. He could do it at will when his butt came off the seat over rough terrain. I told him to slow it down where it's rough and keep his butt in the seat. Problem solved.... This could have been where a homeowner might have replaced the coil,carb, ect without ever fixing the problem. Just try to eliminate everything you can before you buy your first part. Good luck.

[steveair]

hello,

thanks for all the info so far.....Greatly appreciated!

I'm gonna try and get started tommorrow and see what I can find. I have a friend who's done quite a bit of work on his lazer's with kohlers to help out, so hopefully between the info you've all given me and a little luck, we'll figure out the problem.

Be back in touch when I get started I'm sure!

By the way, Stop argueing, will ya'! lol

steve

[Jman]

steveair,
What was the outside temperature the day that happened? Also what was the humidity that day as well? Does your engine have an anti-icing kit installed. Having grown up in northern Iowa we found icing up in the carb to be a big problem. This can happen in temps as warm as 35-40 degrees. The air is super cooled as it goes through the carb. The crankcase on the kohler engine is attached to the air cleaner system as well. This provides the moisture to cause ice build up in the carb. My next suggestion would be that if the unit acts up again, immediately remove the air filter and look down the throat of the carb. If ice is present you will need an anit-icing kit to keep it from happening in the future.

[hal]

Check your ignition modules, when they get hot they expand and shut down, thus the backfire and power failure. I had to replace mine had the exact symptoms.