Kohler K341 loosing power, maybe overheating??

Discussion in 'Mechanic and Repair' started by coyote556, Jun 14, 2008.

  1. coyote556

    coyote556 LawnSite Member
    Posts: 23

    I have a nearly new Kohler K341 replacement engine in my Simplicity tractor. After mowing for 10-20 minutes, it starts to loose power and die down. Sometimes, if I choke it, it will continue to run, however this does not always work. I have checked the fuel system and cleaned the carb out twice, blowing out all the jets. One thing I have noticed, which makes me wonder if it is getting hot, is the fact that the carb is so hot when it starts doing this that you cannot even get close to touching it. if you spray carb cleaner on the side of the carb when this happens, it boils and sizzles right off. I was just wondering if the carb could be getting so hot that it is boiling the fuel in the bowl? also, i have checked all the cooling fins and they are clean and clear. Usually, when this problem happens, I can let the mower cool off and it will be good for another 10-20 minutes. I also wanted to tell you all that I have checked the bowl after this happens (when it is cool enought to touch) and there was fuel in the bowl, so I suspect the fuel pump is working fine. any help is greatly appreciated.
     
  2. Bill Kapaun

    Bill Kapaun LawnSite Senior Member
    Posts: 923

    I wonder if the flywheel key is partially sheared. Sounds like the ignition timing is ********.
    Since you say "nearly new", I assume the cooling fins are clear?
     
  3. coyote556

    coyote556 LawnSite Member
    Posts: 23

    is there a way to check it without pulling the flywheel?
     
  4. Bill Kapaun

    Bill Kapaun LawnSite Senior Member
    Posts: 923

    Do you have Xray vision?
     
  5. coyote556

    coyote556 LawnSite Member
    Posts: 23

    I guess that answers my question about the key. Also, is it normal for that carb to be that hot? thanks
     
  6. kawasaki1

    kawasaki1 LawnSite Member
    Posts: 108

    check your point gap.
     
  7. coyote556

    coyote556 LawnSite Member
    Posts: 23

    to check the timing or could the point gap cause the overheating? thanks
     
  8. kawasaki1

    kawasaki1 LawnSite Member
    Posts: 108

    when the points close it retards the timing.

    couple of questions.

    has it run well before?

    do you have the plastic insulator between the carb and engine block?

    is there adequate airflow to and from the engine?

    is the fuel line run near the cylinder head or muffler?
     
  9. coyote556

    coyote556 LawnSite Member
    Posts: 23

    It used to run good, but has gotten worse recently. When I first got the engine new, I never could get it to run good at all, it was like it was always lean. It had one of those walbro fixed jet carbs that came with it. I changed it over and put on an older adjustable jet kohler carb (#30 bore) and then it ran good, until this problem developed.

    The fuel line is not near either the muffler or the head. As far as air flow, it is a Sovergin series simplicity tractor, so it does have a full hood, but the sides are open. I am not sure on the plastic insulator block. I will have to check on that. If they do not come with the Kohler replacement service engines, then it does not have it. Thanks for the help
     
  10. Partsangel

    Partsangel LawnSite Member
    Posts: 80

    I like Bills point about the flywheel key, I would go and check it first, even tho its a steel half-moon key. air cooled engines run HOT thats what they do, matter of fact some parts of your engine will run at 1200 degrees which is the melting point of aluminum. you have an old K series engine which is cast iron so no probs there. After the flywheel key issue is resolved I would go to your valve clearance and make sure thats up to specs, because as and engine heats up it is very common for metal parts like your valve stems to expand.. get longer.. and take up the clearance (long story) anyway if this is your problem your engine will die just like it ran out of gas till it cools down again. Next thing is Vapor Lock...check and make sure your gas cap is venting air into it.

    FYI
    According to the 2004 or 2005? Kohler Update Seminar there will be no replacement short blocks available for your engine K301 thru K341 because they dont meet EPA standards.. again (long story)

    I hope this helps

    Mike
     

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