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  1. #1

    Default Yammie 1997 150 saltwater- 1 spark plug spotless clean as well as threads ??

    New to me yammie 1997 150 saltwater II - good compression even at 120 psi on all 6
    5 plugs look normal except bottom right (#5?) is spotless including threads- looks like it was put in and never fired- I understand that water will clean top of plug - but threads are spotless clean also- questioned seller- he says these were put in 2 years go- NO WAY - ?

  2. #2
    Join Date
    Sep 2010
    Location
    ontario
    Posts
    15,264

    Default Re: Yammie 1997 150 saltwater- 1 spark plug spotless clean as well as threads ??

    Clean plug means no spark to that plug.---Or no fuel / too much fuel.-----Or no crankcase compression on that cylinder.------A V-6 runs very well on 5 cylinders.----Does spark jump a gap of 3/8" or more on all leads , yes or no.

  3. #3

    Default Re: Yammie 1997 150 saltwater- 1 spark plug spotless clean as well as threads ??

    Just checked per your suggestion - yep 3/8" or more.
    Check spark on "clean" plug - all good. Guess I will fire up this weekend and and start pulling plugs wires to see it it drops a cylinder out-
    So I expect carb build next.

    Need a wiring diagram - end cut off one cable -
    Thanks for response-

  4. #4

    Default Re: Yammie 1997 150 saltwater- 1 spark plug spotless clean as well as threads ??

    Found water in #2 and #6 cylinders. Tore block down- everything looks excellent except some cracks in front half of block- these go not go thur to machined surface inside.
    Drained on engine oil tank- it was full - after it set for a 1/2 hour in clear jar there was 3/8" "water" at bottom of jar. Since only 2 cylinders appeared to have water I do not think this is source of water in cylinders.
    Where is water coming from? Head gaskets did not look damaged.



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