FT50 Yamaha overheat?

[Tspeed]

I have an 03 FT50 Yamaha and it over heats. Low revs.
Water pump is new. Have had new stat. Exhaust plate removed and cleaned. Head off and blown through. Power head off and checked but no signs of corrosion or blockage.
Please help.
Thanks.

 

[pine island fred]

Re: FT50 Yamaha overheat?

I have an 03 FT50 Yamaha and it over heats. Low revs.
Water pump is new. Have had new stat. Exhaust plate removed and cleaned. Head off and blown through. Power head off and checked but no signs of corrosion or blockage.
Please help.
Thanks.

The plastic water pump housing has a stainless steel cup type lining. When you replaced the impeller, the concentric liner became un indexed causing the liner to rotate some blocking off part of the pump outlet. Go back and put the liner back into position making sure it does not come out even a little bit as you push the impeller into it. FRED

 

[Tspeed]

Re: FT50 Yamaha overheat?

If the stainless cup is not located on its tangs into the plastic housing it will not sit flush and bolt down.
As said. New water pump and still the same.

 

[pine island fred]

Re: FT50 Yamaha overheat?

You will find that the 2 small tabs pressed into the cup are pressed flat as well as new indentations pressed into the plastic housing. Gain access to view the pump outlet, there should be no stainless steel visible. If you see steel over the outlet, the cup is skewed. More common than you may think. At this point, what do you have to lose?
I do not know about 50 4 strokes but V-4 2 strokes have a pressure relief valve under a housing cover. Is a spring and disk that corrode in salt water, if you are in salt. regards FRED