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23 HP Kawasaki RPM WAY Too High

Discussion in 'Mechanic and Repair' started by canam, Jun 4, 2006.

  1. canam

    canam LawnSite Member
    Messages: 6

    I have a 61" Scag with a 23 HP Kawasaki FH680V that needed the valves reseated. I thought it would be a good idea to try and tackle that today. I went to my dealer and bought everything I needed yesterday. I was able to complete the job. While I was at it I also cleaned the carb. The motor starts and runs, but now it revs way too high all the way from idle to full throttle. Idle now sounds like 3/4 throttle did prior to the work. At full throttle it sounds like it wants to take off.

    During the process of the work I had to remove the throttle plate and in an effort to fix this RPM problem I tried to adjust the governor per the Kawasaki manual. It didn't work. I am guessing the problem is somewhere in one of these two items or the carb. I need to mow tomorrow and this is the only machine I have. Any suggestions about how to fix the problem would be greatly appreciated.

    I know it was stupid to do this, but I am young and poor and was trying to save some money.
  2. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    If you have a manual sitting there look in it and make sure you have the throttle linkage and gov. spring in the right places, It also tells you how to adjust the high speed no load rpm. The manual has all the answers to your problem.
  3. TLS

    TLS LawnSite Fanatic
    Messages: 7,943

    Yeah, my guess is that a throttle spring is in the wrong hole causing too much spring pull on the gov arm.
  4. Envy Lawn Service

    Envy Lawn Service LawnSite Fanatic
    Messages: 11,087

    Yep, your governor plate is out of whack.

    You'll need to adjust that, and you'll need a tach to do it properly... along with some patients.

    The screws that hold the governor plate have serated heads/bite heads to keep them from vibrating out. Right before they get so tight the plate can no longer move... well the serated heads will make the plate want to 'climb' up or down. So if you don't watch it will move a lot without you noticing and it doesn't take a lot to rev her up.

    But if you can do the valves, you can do this.. heck even I can.
    Just stay calm... lol... it aggrivates me when I have to do it... and it's about time for adjustments on mine too...
  5. DLCS

    DLCS LawnSite Platinum Member
    Messages: 4,385

    Also, don't overtighten those to screws that hold the plate. They thread into aluminum and it strips out easily(been there done that). I'll post a link to a pic that may help you.
  6. DLCS

    DLCS LawnSite Platinum Member
    Messages: 4,385

  7. canam

    canam LawnSite Member
    Messages: 6

    Thank you all for the help. I have adjusted the throttle and it works, but now I have a new problem that I can't find in the manual. When I engage the blades I am getting a puff of black smoke. If I engage the blades at high speed it happens immediately and if I engage at low RPM it puffs when I rev up. There is also a slight popping sound that wasn't there before. ANy idea what this could be? Any suggestions would be appreciated.

    I did learn one lesson. Take it to the dealer for service.
  8. canam

    canam LawnSite Member
    Messages: 6

    I just did a little more investigation. The choke is not sticking. The intake valve on cylinder #1 has a gap of .050". Could this be causing my problem? I must have adjusted it off of TDC. Thanks

    FIXDISS LawnSite Senior Member
    Messages: 445

    Check manual for proper carb. adjustment. It sounds like it is just a little too rich.(black smoke generally means flooding). If not noted in manual then wave at Restrorob. He's the expert.
    As far as the "take it to dealer" comment, just look how much knowlwdge you gainned and all the new friends you made by taking on this job yourself.

    FIXDISS LawnSite Senior Member
    Messages: 445

    Check manual for proper valve lash and re-set them as instructed in manual.That sounds like it is far too much gap. Usually more like .006 and .010 . Again Restrorob can help you.

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