Force 120 Heating problem

[SuzieQ]

I have just replaced the thermoswitch, thermostat, and the impella but still the overheat horn goes off after about 5 minutes at 4000 rpm--Maybe I have the thermostat in wrong--any ideas?

 

[JUSTINTIME]

Re: Force 120 Heating problem

you could
as long as you put it in the same way as it came out

drop lower unit again and put a hose on the tube that goes to the water pump
see if water comes out

 

[scottie]

Re: Force 120 Heating problem

First post guys - great forum - have been reading for a while but just registered to get in on this -

My 85HP is the exact same - new impeller and thermostat - still overheats at high RPM's? Pulled my discharge line and have lots of water coming out at idle (oh yeah - mine is an L-Drive). All I have been reading is that it must be the head gasket - correct? Any other things I should check first?

 

[Frank Acampora]

Re: Force 120 Heating problem

SUSIE Q: If your engine is older than 1989 then you need to check the torpedo shaped plate (held to the lower unit with three screws) under the impeller. You do not need to remove it, just the pump body and stainless plate. If the gasket underneath the stainless plate is torn up or missing. OR if the center dividing wall is badly corroded so that the gasket does not seal it, that could be your problem A bad seal here could allow a portion of the water to short circuit from pump outlet to inlet, reducing the amount of water pumped at high speeds.