Kohler K301 issues

ford2go · #1 (**permalink**) 05-20-2009, 07:52 PM

Hi,
I have a Wheel Horse with a Kohler K301 12 hp. It seems to be one of the later ones.

When I was out mowing today, it would lose power, slow down, and backfire through the exhaust.

I changed the fuel filter, and filled the gas tank (it had some 50:1 mix from my chainsaw -- but I've done that many times) No help.

I put a scope on the points and the plug wire -- doesn't seem to be ignition. Also, the regulator seems to be trying to keep it going, but it just can't.

It happened after it warmed up a bit, and it generally will run longer at low speed. If I crank up the throttle it usually starts to fail fairly quickly.

It was doing this a couple of years ago and they did a head gasket. points, cap, fuel filter, air filter and fuel shutoff.
Was better after that, but I don't think that they ever really identified the problem.

I'm guessing that either something is making it run rich, or the the valves might be sticking -- but I'm far from an ace at this stuff.

Greatly appreciate any thoughts

Milwaukee1979F150 · #2 (**permalink**) 05-20-2009, 08:23 PM

I have same problem with my case 222

it was bad coil plus spark plug and spark plug wire then it run fine now.

ckal704 · #3 (**permalink**) 05-20-2009, 09:27 PM

" backfire through the exhaust" happpens when unburnt fuel hits the hot metal inside the muffler.
The condition occurring and worsening after the tractor has run for a while fits with a faulty coil. As it heats up and expands as a result, an intermittent break inside the coil can show itself by causing erratic spark.
If possible, run it until it starts happening and put a spark tester inline with the spark plug. You should be able to discern intermittent firing.
If you don't have a spark tester, an timing light also will show an intermittent spark with the irregular flickering of the light.
This is only true if the spark is cutting out completely, not just a weakened spark. A weak spark lacks the voltage to jump the gap across a tightly compressed air and fuel mix, but might be strong enough to trip the timing light and make it flash. A bona fide spark tester with a wide air gap (about .166") will show whether or not enough voltage is present to jump the gap under compression conditions.
I don't think that it is a fuel issue.

Let us know what you find out!

Lead Head · #4 (**permalink**) 05-20-2009, 09:58 PM

What color is the spark plug right after it dies. Very thick soot/wet indicates far to rich or poor ignition/spark. White ash-like deposits mean its leaning out.
A good fuel mixture will yield a fairly clean electrode with a light coating of tan-ish deposits, which is how my K301 runs.

This may sound dumb, but have you checked to make sure its not soft-seizing?

ford2go · #5 (**permalink**) 05-21-2009, 01:31 AM

Thanks for all of the replies.

I will try to check the ignition again. I did wonder if it was a coil problem.
But, I did put a scope on it with a secondary ignition probe. Had the points on one channel and the spark on the other. Didn't see any evidence of misfire as it started to fail. Will look at it some more -- or maybe just try a new coil, etc.

As to Lead Head's comment -- I have a vague idea of what you mean by soft seizing, but I have NO idea of how to check for it. I'd appreciate any enlightenment.

Thanks,

Lead Head · #6 (**permalink**) 05-21-2009, 02:48 PM

See if the crank shaft is any harder to turn by hand right when it dies, vs. when it is cold.

Ford_Six · #7 (**permalink**) 05-22-2009, 01:20 AM

Does that engine have an automatic compression release for cranking? It might be the mechanism for that is hanging up.

Lead Head · #8 (**permalink**) 05-22-2009, 02:35 PM

Yes, the K301 does have the automatic compression relief. I suppose its possible it could be re-engaging, but usually once its deactivated, it stays off once the engine is upto speed because of the flyweights on it.

ford2go · #9 (**permalink**) 05-24-2009, 02:25 AM

Doesn't seem to be ignition, and it's running way rich. Plug was sooty -- new plug started to turn black after about 10 minutes(doesn't seem to be oil).

It quits with a different coil, different plug wire and a new plug.

Planning to put in a carb kit and a float kit, but... how can I get the float seat out?

Only thing that fits is a pliers -- and they caused a little damage without breaking it loose.

Special tools ? Other tricks?

Thanks,

ckal704 · #10 (**permalink**) 05-24-2009, 08:53 AM

Here is the repair manual:
http://www.kohlerengines.com/onlinec...df/tp_2379.pdf

Lead Head · #11 (**permalink**) 05-24-2009, 09:20 AM

Float seat, do you mean needle seat? When I took my K301's carb apart, there was nothing you needed a pair of pliers for. The pin for the float just pops out with a bit of pressure from a pin, the needle just should fall out, and the needle seat should have a hex on it to fit a socket over. I believe you need a thin wall socket though.

ford2go · #12 (**permalink**) 05-25-2009, 12:35 AM

I'll look for a thin wall socket -- my normal ones interfere with the two prongs that hold the pin. Do you like a particular brand of thinwalls?

And thanks for the link, but I have that manual. It pretty much says 'remove the seat'. It's not a bad manual, but it can be a little brief.

ckal704 · #13 (**permalink**) 05-25-2009, 07:59 AM

Just sent it to illustrate that some float needle seats unscrew and some have to be pulled. Didn't know if you had the Kohler carb or Walbro.

ford2go · #14 (**permalink**) 05-25-2009, 04:25 PM

I appreciate the thought. It is a Kohler. Right now, I'm debating leaving the seat in place -- it looks pretty good.

I'd prefer to take it out, but I'm having a little trouble finding a thinwall socket.

Lead Head · #15 (**permalink**) 05-25-2009, 04:43 PM

Not sure if you'd want to, but your local autozone should have a rent-a-tool program where should be able to rent the proper socket.