water in cylinders

[Mkos1980]

Last year had no problems so this year I went to change the oil since I ran out of time last year only to find some traces of water... I pulled all 4 plugs on driver side. Looks nice and dry. I pull all 4 on passenger side and all wet. I pulled the riser off to find a saturated gasket and coolant in the bottom of the manifold. I Pulled The Manifold And Numbers 3 5 And 7 Exhaust Ports Had FILLED Up With antifreeze and number 1 ex valve was open so the piston had coolant in there. Is it safe to say the riser gasket is the cause of this? Manifolds are glm Aluminum ones I installed in 07. Zero pitting on manifold and risor. I did not run the motor once I filled the motor up with antifreeze.. 1990 mercruiser 350. 260hp

 

[alldodge]

Last year had no problems so this year I went to change the oil since I ran out of time last year only to find some traces of water... I pulled all 4 plugs on driver side. Looks nice and dry. I pull all 4 on passenger side and all wet. I pulled the riser off to find a saturated gasket and coolant in the bottom of the manifold. I Pulled The Manifold And Numbers 3 5 And 7 Exhaust Ports Had FILLED Up With antifreeze and number 1 ex valve was open so the piston had coolant in there. Is it safe to say the riser gasket is the cause of this? Manifolds are glm Aluminum ones I installed in 07. Zero pitting on manifold and risor. I did not run the motor once I filled the motor up with antifreeze.. 1990 mercruiser 350. 260hp

It you be a good bet that the gasket is the issue. Where the riser bolts loose?

 

[Bondo]

Manifolds are glm Aluminum ones I installed in 07. Zero pitting on manifold and risor.

Ayuh,.... Check 'em with a straight edge, 'n feeler gauges,.....

Had to remachine mine flat, as the inner gasket surface was considerably lower than the outer edge,.....

Right outa the box,....

 

[Mkos1980]

Boats tight to 30lbs. Was using paper gaskets. I put a straight edge on them and they are perfectly square. I upgraded both sides to the soft metal ones and torque to 33lbs. Well see what happens !

 

[Mkos1980]

When I got my GLM's back in 07 mine were slightly off. I had the local machine shop hit the manifolds and risors and true them up. i'm surprised they leaked. When i put them on 7 years ago they had given me green hard paper gaskets. It looks like the gaskets dried out and hardened when I took the riser off. The small gasket portion around the exhaust rise was saturated in coolant from winterizing.