40HP Force Overheats

[dave 416]

Motor is a 1992-1994 40hp just replaced the impeller still the same problem took the thermostat out started the motor and exhaust is coming out could this mean a bad bypass cover . Any help appreciated thx.

 

[Frank Acampora]

Re: 40HP Force Overheats

NO! Exhaust coming out the thermostat housing hole means that exhaust is getting into the water jacket. This means that either a head gasket is broken (most likely) or a cylinder is cracked. First check compression to see if one cylinder is low. Then pull the head and eyeball the head gasket. If it appears OK, then slowly turn the engine and check the cylinder walls. Aslo check the head and cylinder gasket seating surfaces.

Sometimes corrosion will damage the seating area on the head ot tops of the cylinders. If this is the case and it is not too bad, it is possible to machin the surfaces again.

 

[dave 416]

Re: 40HP Force Overheats

thx frank for your reply will check it out. there is zero water coming out of the thermostat hole. when i hook the hose up to the water pump pipe i get water so there is no blockages