Water getting to plug

[Taylorld]

Purchased 45 HP mariner last year on pontoon boat, owner said had been recently rebuilt. Took it to lake two times last year, had trouble with initial start up, motor was too tight to crank. Removed plugs and turned it over several times squirted gas in cylinders and it fired up.

Now problem: yesterday was going to take to lake after sitting for about one year, same hard to crank issue, removed plugs and noticed small amount of rust on lower plug, gas to cylinders cranked great. However removed plugs to check and saw the white milky foam of water and oil mixture on lower plug.

Know very little about cooling system on power head of an outboard. Where should I start looking for the leak?

 

[glenn property of pam]

Re: Water getting to plug

Your problem could be condensation that has built up in the crank case, water in the gas, or a cooling water leak.
Best place to start is with a compression test if that passes then get fresh gas and open the carb drain screws and empty the bottom of the carbs then leave one carb drain screw out (the easiest to collect the gas) and purge the line by pumping the bulb so fresh gas is pumped from the tank and the old gas is collected at the carb then empty the other carbs again. Replace all drain screws and refill the carbs with the hand bulb then replace the plugs and test again.
Get the engine to start and allow it to reach full temp then cool and recheck the plugs

 

[Chris1956]

Re: Water getting to plug

Water in the lowest cylinder is likely due to bad crank seals. They will rust the rings to the cylinders. Water in upper cylinder is likely bad exhaust cover gaskets, hole in baffle plate or some combo. Run the motor for awhile and then look at the spark plugs. If they are perfectly clean (not black or brown), you are getting water in that cylinder.