Kawasaki FH770D 28HP sputtering under heavy load

Discussion in 'Mechanic and Repair' started by lotsagrass, Aug 17, 2012.

  1. taxidermist

    taxidermist LawnSite Member
    Messages: 49

    Dont do them both at the same time...start cheep that way you will know if it was a plug or coil

  2. lotsagrass

    lotsagrass LawnSite Senior Member
    Messages: 783

    If it keeps acting up I'll replace the plugs since that's really cheap and easy. If it still has the problem, then the coils will be replaced.
  3. LarryF

    LarryF LawnSite Bronze Member
    Messages: 1,177

    Why haven't you tried replacing the right coil since it's measurement was only marginal?
  4. lotsagrass

    lotsagrass LawnSite Senior Member
    Messages: 783

    I read that in some cases it's required to replace both, as a pair. I think someone had posted a tech note from Kawasaki that was intended for repair shops. I don't remember exactly where I saw the notice I'm talking about, but if I do have to replace one, I plan on replacing both at the same time.
  5. LarryF

    LarryF LawnSite Bronze Member
    Messages: 1,177

    Someone might have posted that, but I don't believe it to be a valid requirement since I changed only the one on mine that was bad as indicated by a low resistance measurement, and that cleared my problem.
  6. N.H.BOY

    N.H.BOY LawnSite Bronze Member
    Messages: 1,603

    Sounds like this is driving you to drink...Have you replaced all rubber fuel line hoses? Cheap and easy, they sometime do have small cracking and get old. I do wish you luck
  7. lotsagrass

    lotsagrass LawnSite Senior Member
    Messages: 783

    I ordered new coils (both) and new plugs from Partstree a moment ago. Today while mowing, it started to backfire (not really loudly, but still doing it) very frequently and not under really heavy loads. I do believe it's mostly ignition related. I assume there's unburnt fuel that's causing the backfires. I took readings on the coils after getting them off and only one of them had a normal reading (left one) and the other was up into the mega-ohms instead of kilo-ohms where it should be. Overall I was having a hard time getting a reading at all. Anyway, If this doesn't cure the problem, I'd be pretty surprised. I've used octane booster in the last two mowings and I think that's helped it run better with the bad coils...but it seems like the problem is growing worse and being more consistent now. I hope to have the replacement parts by mid week. The dealer said he'd have to take the engine off to get the coils off, but I did it at home without removing the engine. It's a little tight, but it's a lot less work than removing the engine! My biggest pain in the butt I'm sure will be making sure the clearance is set right (between the coil and flywheel). I know what the clearance should be, but I'm just saying it's going to be tough because the workspace it tight.

    Last edited: Sep 21, 2012
  8. blabarre

    blabarre LawnSite Member
    Messages: 86

    Cool. Keep us posted!
    Posted via Mobile Device
  9. teckjohn

    teckjohn LawnSite Senior Member
    Messages: 275

    Exhaust valve staying open when it fires will also do what your saying. And these Kawasakis are famous for valve guides sticking and the head going bad and sticking a valve and destroying a piston and a block. Could have a warped exhaust valve. http://www.lawnsite.com/showthread.php?p=4409832#post4409832

    is what they are famous for. NEW and OLD!
  10. lotsagrass

    lotsagrass LawnSite Senior Member
    Messages: 783

    I hope not :-( If the coils don't do the trick, I guess that's the next thing to check.

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