Boat engine over heating

[alan_fincher]

I've just took thermostat housing off and there wasn't a thermostat to be seen,so that's the problem solved hopefully.

 

Sadly, no.

If it is overheating with no thermostat present, putting one back is unlikely to fix it. No thermostat will stop it getting hot enough, but I can't see how it could cause it get too hot.

[Ianmc]

Next check is water pump,as been told head gasket was ok,new cap and thermostat fitted now,I'll turn engine on and see what happens now

[Ianmc]

I've had the boat 1 year,just done fit out,moved to bosworth Marina and we over heated on route.

[Stilllearning]

If it is anything like the LPWS4 that I had, and there are many variants, it might have a multi vaned rubber impeller fitted at the front end of the engine, behind a small circular brass or maybe green painted plate. These impellers often lose a vane or two that can get stuck in the outlet hole from the impeller housing. It may be worth checking this, if you haven't already.

[RLWP]

If it is anything like the LPWS4 that I had, and there are many variants, it might have a multi vaned rubber impeller fitted at the front end of the engine, behind a small circular brass or maybe green painted plate. These impellers often lose a vane or two that can get stuck in the outlet hole from the impeller housing. It may be worth checking this, if you haven't already.

 

Presumably you had raw water cooling if you had a Jabsco pump

 

Richard

[Stilllearning]

Yes indeed, so that might make my observation irrelevant to the OP.

[Sea Dog]

Unlikely. No thermostat is usually a sign of folk engineering. 'It's overheating' - 'take the thermostat out'. 'it's still overheating - hello - hello?'

 

Richard

Sadly, it can also be a sign of someone knowing the engine overheats and taking the stat out to delay the warm up long enough to demonstrate the engine/vehicle to a potential buyer.