ox66 225 yamaha runs hot

[hul-a-blu]

ive got 2001 yamaha 225 ox66, thats tryin to over heat. the water pump looks like its pumping fine but the top 2 cylinder are getting warm, and the alarm goes off. it deos it at an idle. i took the thermostats out. still the same. its doing it with muffs and in the lake. any ideas thanks

 

[cousinabe]

Re: ox66 225 yamaha runs hot

are the cylinder heads too hot to touch?
if not, could be a faulty thermo sensor.
try unplugging the pink wires.

 

[hul-a-blu]

Re: ox66 225 yamaha runs hot

yes they are hot to touch

 

[cousinabe]

Re: ox66 225 yamaha runs hot

when was the last time you serviced the water pump?
i change mine ever other season.

 

[hul-a-blu]

Re: ox66 225 yamaha runs hot

i replaced it last year, about 100 hours ago

 

[DMSOUTH]

Re: ox66 225 yamaha runs hot

check the pressure relief valve--if it's stuck open, there won't be enough water to get to the top cylinders at idle...

 

[PBJohn]

Re: ox66 225 yamaha runs hot

Verify your idle speed is within spec. Too low can cause it to run hotter.

 

[k4ubr]

Re: ox66 225 yamaha runs hot

i would say replace water pump assy. the plastic housing will melt stoping it from priming.

 

[snowmon]

Re: ox66 225 yamaha runs hot

dm souths right. replace the poppit valve. make sure yor remove the old gromet and clean up the opening removing any corrosion. this is what keeps the valve from moving free. if stuck open just dumps water

 

[cousinabe]

Re: ox66 225 yamaha runs hot

I agree. I would check the poppet valve / pressure relief valve next.