# Kohler Command Pro 20 starts then dies



## Average Joe

I purchased a used Dixon 6022 ZTR mower that has a Kohler Command Pro 20 OHV engine on it. It ran fine for the few first months I had it. The other day I let it warm up--always cold natured for about 5 minutes and the motor shut off. I tried to restart and it would run for about 3 seconds then die.

What I have done so far and my results:

1. drained gas, blew out lines, verified vent cap to be open, refilled with fresh gas--same thing starts on choke, then dies 

2. removed gas line from carb and verifed fuel pump was sending gas also replaced fuel filter--sends gas same results.

3. removed carb, cleaned out with carb cleaner and blew clean, reinstalled same results.

What else am I missing? The carb is definately getting fuel to it, the engine is firing over, it is almost like something is cutting the air or spark off after the engine starts. The only safety switches on the unit are on the PTO/blade switch, the seat, and the hydraulic drive arms--all seem to be in the correct place.

Any suggestions?

thanks,

Joe


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## bugman

it could be the coil or the plug is bad try those first. the other thing it could be is one of the butterflys in the carb has a loose or worn out spring causing it to choke out.


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## Average Joe

bugman,

pulled plugs and they "looked" good but I will replace, that time anyway. Will check it out and post back tomorrow.

thanks,

Joe


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## Redline Tech

A Honda on a generator did the same thing. It had a tiny spec of debris stuck in the jet orifice. It allowed just enough gas to start it every time, then it was starved and died. Did this over and over ad finitum. Cleaned the out jet and all was fine. I wonder if the Kohler is the same way (I'm new to small engines).

:thumbsup:


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## shopteacher

Did you ever find out the problem? I was wondering if it was a safety switch issue. Let me know.


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## scrench

i would check the fuel shut off solenoid make sure it has power to it , and is grounded :thumbsup: also might check ground to" coil " i would disconnect kill wire and try it , also you can check the key switch and safety switches by hooking your test light on the + side of battery , turn key to on position if light stays on then it could be the switch or switches sounds to my like the key switch , but if you take the kill wire off @ the " coil" it will eliminate all wires just my 2 cents :thumbsup: i would make sure the wires are plugged in good at the wiring harness and clean the one near the engine , might be @ worst the speed advance module , but that would be where i went last , could be tank venting


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## bugman

haha just like my old murray. wiring was shot. kill wire kept falling out. it has no fuse to the alternator and it doesn't charge but the alternator works and powers the lights. key switch fried. did a little snipping and crimping and all was good. kill switch wire still falls out and i don't want to buy another key switch plug. but it runs good. no safety switches at all. don't like em.


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## Average Joe

haven't found the problem yet, replaced the plugs etc. still the same issue, haven't had time to get out the test light yet but now with snow on the ground hope to dig in this holiday weekend. I will post back with results.

thanks all!

Joe


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## Scott15

Kohler. I thought they were good?


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## bugman

some will have their problems. all will eventually get their problems in time.


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## starfire383

I'd try trickling some starting fluid or aerosol carb cleaner into the carb opening. This verifies that it's a fuel delivery problem. If you can't keep it running beyond 3 seconds this way, then you know it's an ignition issue.
Just don't get extremely close with the aerosols. You're just adding fuel, not supercharging.


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## bugman

that or gasoline into it.


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## scrench

this engine has problems with the cam gear slipping on the crankshaft causing valve interference not saying this is happened but possible , just pulled out my hair out on one ,


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## bugman

yeah its a hair puller and put it back in and pull some more :lol:


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## Average Joe

scrench, you may be on to something, when I pulled the plugs I noticed one plug looked like it was almost bent in. It is definately ignition or non-fuel related... nothing keeps it started more than a few seconds.

Going to do the ignition check tonight. Will post tomorrow.


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## bugman

gotta be something with the cam and timing.


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## scrench

the one i faught was shooting alot of fuel back through the carb but if i primed it would try to start , the mower came to the shop , you could tell the timing was off when you cranked it over so i tore into it the cam was broke well it had like 5 teeth broke so i put a new cam in it and done valve job and ringed it , put it back on/ done the same thing, tore back apart had bent valves , so i started looking @ the gear on the crank , the stupid gear is pressed on no key nothing just pressed , 240 bucks for crank shaft


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## bugman

ouch.


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## Scott15

Get another engine. :thumbsup:


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## bugman

240 bucks plus maybe 100 give or take is still better then a new engine. plus to me its fun to work on them.


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## scrench

bugman said:


> 240 bucks plus maybe 100 give or take is still better then a new engine. plus to me its fun to work on them.


for sure.... he had arround 550$ in the engine , the mower was a z-trax had been rode hard and put away wett ,,, mowed alot of grass and alot of rocks ,, gotta love it !!!!!


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## bugman

exactomundo


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## Average Joe

All right, finally got back to the garage and some time away from the wife and kids. Glad it is cold here and I don't need this thing right now! The problem is at the fuel shutoff solenoid. When the key switch is in the starter position it has power to it and allows the engine to start, when the key moves back to the on position it loses the power to it and it shuts off. I have checked all connections and they seem to be tight. I did run a hot line from the battery and after starting it aligator clipped it at the solenoid and the engine ran just fine, even off choke. So, having said that is it the key switch it self or should I look at something else? Also, what would be the harm in just clipping in a new run from one of the pins on the starter switch that stays hot when in the on position--kind of a farmers fix.

Thanks to everyone that has posted ideas here!


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## scrench

you can do that or the way i do it sometimes is grind the point off it.but sounds like its the key switch thats bad


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## scrench

might be a fuse


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## Average Joe

checked fuses and all are good--only found 2 total on there...


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## Average Joe

scrench said:


> you can do that or the way i do it sometimes is grind the point off it.but sounds like its the key switch thats bad



forgive my ignorance but what do you mean by "grind the point off" ?


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## scrench

off the antibackfire "fuel shut off solenoid " take it out of the carb and i think that one might have a a round piece on the end thats rubber take that off and grind a little off the tip that solenoid is what kills the fuel when it has + to the solenoid it opens it no juice closes it when you grind it off it wont shut the fuel off ,,


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## scrench

i think if it was me and being this time of the year i would find the problem , it might not be charging , some times if the switch goes bad they wont charge , we all need more time in the garage this time of the year lol i'm building a shovel head 90 incher thumbs up


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## Average Joe

Well got it running good. The switch itself has 5 pins on it. The one that supposedly powers the solenoid on ignition on gets power when the key is on. I tapped into it and ran to the solenoid-for now it works. The problem is somewhere between the switch and the solenoid.

Thanks for everyone's help!


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