9.9hp Merc (1999) Water intrusion at spark plugs

[derfxa]

My 1999, 9.9hp Merc, 2 stroke is getting water into the combustion chamber somehow and fouling the plugs, I've replaced, four gaskets: two under powerhead and one side gasket behind CDI and back gasket where the plugs are. Where else could the leak come from?

 

[verado7]

Re: 9.9hp Merc (1999) Water intrusion at spark plugs

cracked block or 1 of of your covers is warped and not sealing properly - not uncommon and usually it's teh water jacket cover .

 

[derfxa]

Re: 9.9hp Merc (1999) Water intrusion at spark plugs

RESOLVED --- the two gaskets on the port side exhaust and water jacket plates/cover were put on in wrong order by prior owner, outside gasket was on the inside.... almost gave motor away for $200 bucks....

 

[verado7]

Re: 9.9hp Merc (1999) Water intrusion at spark plugs

thats good news .