Mariner 48 hp with whitish fluid coated spark plugs?

[bplayer405]

I know I don't want to hear it, but I'm pretty sure my spark plug electrode ends being coated with a thin whitish milky fluid means that water is getting into the cylinders. Any other options before I gather parts to tear down the engine?

 

[Bosunsmate]

Re: Mariner 48 hp with whitish fluid coated spark plugs?

Is it both cylinders?
Start on exhaust gasket, much easier/cheaper than a whole tear down
or better yet start with a compression test

 

[bplayer405]

Re: Mariner 48 hp with whitish fluid coated spark plugs?

yes, it is both cylinders

 

[bplayer405]

Re: Mariner 48 hp with whitish fluid coated spark plugs?

Just attepted to test compression, but my tester doesn't have a good seat on the adapter. It only has threads to seal. I made sure the adapter had clearance by slowly rotating the flywheel past tdc then checked compression. #1 cyl got to 70lbs, #2 got to 75lbs. Didn't do a wet test or try sealing the adapter threads with anything. Just ran the adapter in till it was good and snug.

 

[Bosunsmate]

Re: Mariner 48 hp with whitish fluid coated spark plugs?

Pull the head gasket first, inspect gasket, cylinders and head for failures.
If none move on to exhaust gasket

 

[bplayer405]

Re: Mariner 48 hp with whitish fluid coated spark plugs?

After some other issues with this and another motor I've been using, I've figured out what the "milky fluid" onthe plugs was. I've been using semi-synthetic 2-stroke oil and the same fluid coated my choke on the other motor when it backfired through the intake and died. I fully believe its just the use of this oil. I pulled the plugs on this other motor and they were clean other than normal use-no fluid. I know this other motor has no water infiltration issues. I never saw this fluid when I used conventional 2-stroke oil.