Overheating on strbd bank of V4, 90 hp, 1988

[cadred_1]

Overheat horn goes off after about 10 minutes. Port side head is still just warm, strbd side head is hot. Pulled thermostat hoses and got lot of water out of each head. Pulled cover and head cover off of strbd head. Outside (head cover water passage) had tattered gasket material in passages. Inside head cover revealed water passages around piston were clean as a whistle. From schematic diagrams I saw only one thermostat. Is there a thermostat for each head on the V4? Does it sound like a thermostat problem or was the gasket tatter a source of the problem? I have not torn into the thermostat yet.

[boats.net]

There is two thermostats and a relief valve inside the thermostat housing. May need a new water pump.

[b.robbbo]

Thermostat housing 88 SPL motor

Any tricks on how to get a wrench on the bolts ?