slow reving and low power when engage blades

Discussion in 'Mechanic and Repair' started by 97firebird, Mar 21, 2008.

  1. 97firebird

    97firebird LawnSite Member
    Posts: 41

    Hey guys, I have been messing with this mower for a while, and started last fall before I put it away for a long sit throughout winter. Its a cv22 kohler motor and runs fine except that when I quickly move the throttle up it takes a long time for the RPMs to "catch up" with the throttle position. I cant tell if the engine is starving for fuel or starving for air. Also, when I engage the blades there is never enough power to get them spinning at cutting speed. However, this problem came on suddenly when I went to run the mower last fall...so it was fine one day and running in this manner the next. I did have problems with mice making nests in the mowers before...could have they made a nest in the muffler? I already replaced the fuel filter and cleaned the carb with no success. How can I diagnose this? Thanks
     
  2. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    Sounds like it's only running on one cylinder, Possibly a coil. Make sure both cylinders have spark.

    Loosen both plug boots for easy removal, Start the engine and let idle. Remove each plug wire one at a time with rubber handled pliers etc. and see if it shuts down when one is removed. If it does the one you just removed is good and the other is bad.
     
  3. 97firebird

    97firebird LawnSite Member
    Posts: 41

    I am pretty sure that it is running on both cylinders because I have had a mower running on one cylinder before and I was able to tell immediately when only one cylinder was firing. However, its a simple test, so I might as well try it. thanks for the info...could it be anything else guys? thanks again
     
  4. topsites

    topsites LawnSite Fanatic
    Posts: 21,653

    1. Remove the air filter completely to test this, and if it runs fine without the air filter then it needs a new one.
    > no I know you shouldn't run it like this, but just for a few minutes.
    2. If the oil is black it might need changing, severely polluted oil can throttle your engine.
    3. Fuel filter? If in doubt, replace it.
    4. Spark plugs, just put two new ones in, eliminate this as a possible cause.
     
  5. 97firebird

    97firebird LawnSite Member
    Posts: 41

    I had it running without the filter off and it did not fix the problem...fuel filter has already been replaced as well, and the oil only has about 20hrs on it. I am going to pull the wires on the plugs today just to make sure, but I am 99.9% positive its running on both cylinders...I suppose I can just remove the muffler and run it just to see if the problem goes away. I really have a hard time believing a mouse nest can cause this problem. thanks for the input guys.
     
  6. topsites

    topsites LawnSite Fanatic
    Posts: 21,653

    hmmm...

    I would check up underneath where the pulley is, make sure nothing is binding or out of whack.
     
  7. mowermankevin

    mowermankevin LawnSite Senior Member
    Posts: 270

    After you run this engine, pull the plugs and check them too. The other day a fella had a problem similar to yours and it turned out to be an obstruction interfering with the govenor arm.spring, shaft to carb. My own tugboat garden tractor Kohler has the govenor spring in the wrong slot,so it is slow to wind up, but once it does, its fine, PTO clutch engages and works, just a slow wind-up, ahhh Spring, time to send those mice packing and make room for the bees!!!!
     
  8. 97firebird

    97firebird LawnSite Member
    Posts: 41

    Problem solved!! I feel like an idiot, but the engine was only running on the right cylinder because my dear mice friends chewed completely through the left plug wire...a new coil and she's back and running again... Thanks again guys.
     
  9. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    Hmmm.......Glad to hear it's running on both now. [​IMG]



    Had a customer bring me his Gravley three times one summer for the same reason, The third time I covered the wires with braided steel vacuum hose covering from Summet Racing and hasn't been back since.
     

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