Hard starting 20 hp Kohler Command CH20

NoTrespassing · Mar 8, 2013

Hey All,

Ok, it's not a compact tractor but I thought maybe someone here could steer me in the right direction.

I bought a used 2002 mower with about 1000 hours on it the other day. It's powered by a 20 hp Kohler Command CH20. It seems to be a bit of a "hard starter". I have to crank the engine for at least 10 seconds or more with full choke to get it to start. After it warms up just a little it runs fine. It's almost full of fuel, (5 gallons) and I'll probably use it as is until that runs out. After that I'd like to try something to get it to start more easily.

One other clue that might be of help; It did backfire once after I shut it down.

Where should I start?

My old Briggs fires right up when I barely crank it. That's what I'd like to see out of this Kohler.

Thanks for any pointers,
Kevin

J_J · Mar 8, 2013

Try adding SEA FOAM to a tank of gas.

Do you have a gas shut off valve in the fuel line, if not , better install one.

Have you cleaned the needle valve and seat.

If the carb has the solenoid fuel shut off, you might need to remove it and clean and test it off the carb.

I have had many Kohler engines back fire. After running it hard, let it idle for a while before shutting off.

Check your fuel pump .

RandyT · Mar 8, 2013

J_J said:
Try adding SEA FOAM to a tank of gas.

Do you have a gas shut off valve in the fuel line, if not , better install one.

Have you cleaned the needle valve and seat.

If the carb has the solenoid fuel shut off, you might need to remove it and clean and test it off the carb.

I have had many Kohler engines back fire. After running it hard, let it idle for a while before shutting off.

Check your fuel pump .

Kohler recommends that you shut off the engine at half to full throttle. due to the fact that the solenoid only shuts off the main jet of the carb, but not the idle jet, which will still allow fuel to enter the engine leading to afterfire.

Have a ch20 on a stump grinder, that starts about like you describe, especially if it is cold. Brand new ch20 that I installed in a skid steer, starts harder than that, and it was new out of the box. So it may be just the nature of the beast.

NoTrespassing · Mar 8, 2013

Thanks fellas. I'll give a couple things a try.

Blaneypark · Mar 8, 2013

How ols is the Gas? A new spark plug may help. Use Sea-foam in all your gas.

sox3 · Mar 9, 2013

Make sure the choke is fully engaged. The lever may be all the way up, but the choke flap may not be on all the way. I have found if you lube the cables it will help or adjust the choke.

NoTrespassing · Mar 9, 2013

sox3 said:
Make sure the choke is fully engaged. The lever may be all the way up, but the choke flap may not be on all the way. I have found if you lube the cables it will help or adjust the choke.

Thanks, actually that's the first thing I'm going to check along with adding some Sea Foam.

mitch becton · Mar 10, 2013

one thing also look at this engine is overhead valve i know on the briggs version the valves have to adjusted quite often or it will make you think it has a bad battery or worse it appears that overtime the valves will just tighten up and create a cranking problem

Leo Rabon · Mar 10, 2013

Hello Kevin
Sorry about your troubles. I bought a new Cub Cadet GT2000 in June 2011 with a Kohler Command CH20. Out of the gate it was a hard start (cold) even at 60 degrees. After it was warmed up, I could bump the starter and it would start up immediately. Check to make sure that your fuel pump is good and install a new fuel filter (oem) as the Kohler engines are picky about the correct fuel filter. Ditto on the advice to cool the engine at idle for a bit before shutdown. Also, (ditto) a must is to shut down at one half to three quarter throttle to stop the backfire. If you keep getting backfires you are going to have more trouble.
Good Luck
Leo

NoTrespassing · Mar 10, 2013

Upon further investigation today, I think it's operator error. On a cold start this morning of about 40 degrees F, the engine fired right up with full choke. About an hour later I tried to start the engine again with full choke and had to crank it about 10 seconds before I got enough fire to keep it running. In short, I think I'm flooding the carb. Next time, if the engine isn't completely cold I'm going to use less or no choke.

What position do you suggest the throttle is set at on start up, cold and warm? I'm just learning about this mower and I'm pretty sure it's my problem, not the engine now.