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Results 1 to 6 of 6
  1. #1

    Default pcm excalabur 330, 400hrs engine misifres

    Never had this problem before i just changed the exhaust manifold due to leaking water into cylinder, i also replaced spark plugs

    I have plenty of power , no overheat etc but now when I slow down the engine misfires, never happened before, any suggestions, could it be the new plugs, gaskets etc thanks laurie

  2. #2
    Join Date
    Sep 2008
    Location
    Maryland - USA
    Posts
    5,531

    Default Re: pcm excalabur 330, 400hrs engine misifres

    Have you done a compression or leakdown test?

    Could be the ignition but I'd be concerned about the physical condition of the engine after the 'water leak' was discovered.

  3. #3

    Default Re: pcm excalabur 330, 400hrs engine misifres

    did compression test before changed manifold and was good

    noticed today that 1 new plug had 2 cracks in the porcelain and 1 new had misaligned pin at the end so replaced them, maybe that was the prob???? will do sea test at w/end

  4. #4

    Default Re: pcm excalabur 330, 400hrs engine misifres

    changed plugs, fuel filters, fuel pumps, no o/heat , no prob starting, but under load at 1500rpm everytime starts misfire bad,
    changed exhaiust maniflold just before this misfire issue, any ideas anybody thanks

    Quote Originally Posted by laurie88 View Post
    Never had this problem before i just changed the exhaust manifold due to leaking water into cylinder, i also replaced spark plugs

    I have plenty of power , no overheat etc but now when I slow down the engine misfires, never happened before, any suggestions, could it be the new plugs, gaskets etc thanks laurie

  5. #5
    Join Date
    Sep 2008
    Location
    Maryland - USA
    Posts
    5,531

    Default Re: pcm excalabur 330, 400hrs engine misifres

    same individual install the newest set of plugs that installed the previous set?

    checked the plug wires? not uncommon for them to get damaged when removing them from the plugs, especially on the "hard to get to" side of the engine. how about an inspection of the distributor cap?

    Have you measured the fuel pressure in the rail, especially under load?

  6. #6
    Join Date
    Sep 2006
    Location
    SF BAY AREA, CALI, USA
    Posts
    8,641

    Default Re: pcm excalabur 330, 400hrs engine misifres

    sounds like a bad valve from the water in the cylinder, i not the spark plg


    you do leak down tests on 4 strokes and compression on 2 strokes
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