1999 Mercury 60Hp with unusual problem.

[peterschurms]

Hi... Any ideas appreciated. I'm plum out of ideas. Next one is pull it apart.

Compression is good and the plugs are wet, but only after motor cools down.

The motor was unusually hard to start on last outing. Found the bottom two plugs had water on them. (Which really surprised me as there is no head gasket.) I dried and reinstalled them. The motor started quite easily. The telltail had good strong steam pumping out. Fuel tank is clean, no water.

When its warm it starts and runs fine. The plugs only seem to get wet when it cooled down. Almost like its being drawn in somehow. Its weird.

Any ideas on where to look? Exhaust, Seals, gaskets etc or more serious... cracked block? Are there any things I can check to get to the bottom of it.

3cyl, 2stroke. Motor No: OT064381 175hrs. Cylinder compression 121, 121, 124

Appreciate any help.
Cheers,
Pete

 

[CharlieB]

Re: 1999 Mercury 60Hp with unusual problem.

Failed gasket and/or warped/corroded divider plate on the exhaust side of the motor is allowing water to be 'sucked' back into lower cyl''s exhaust ports.

Remove the exhaust side cover, inspect the divider plate, especially the gasket surfaces along the edges. Make double sure block, plate, and cover are flat and no warps/wows at sealing surfaces. Clean carefully, do NOT gouge while scraping old gaskets off. Reinstall w/new gaskets.

 

[peterschurms]

Re: 1999 Mercury 60Hp with unusual problem.

Thanks CharlieB ... Your info is A-grade, cheers!

I checked it out twice to make sure, it appears that the exhaust divider plate on the side of the motor (Upper LHS) is, as best as i can see, a sealed unit ie there's no bolts or signs of a gasket. I know this probably does not make any sense.

I guess this means my next option is a little more intrusive in nature. I believe the exhaust plate at the top of the leg is my next option then?