1991 Yamaha 40 hp 2 stroke - location of thermostat

[Luke M]

Hi all, I have a 1991 2 stroke 40 hp and I cannot for the life of me locate the thermostat housing?? any assistance would be greatly appreciated ...

 

[Luke M]

engine model is 40QWP ...

 

[Luke M]

actually now that I make further enquiries I think it might be a 1997 model ...

 

[racerone]

Typically found just behind a cover above exhaust manifold.

 

[Edchris177]

Item 30

 

[Luke M]

Thanks, that’s certainly where I am focusing my attention but nothing is jumping out at me … I shall press on

 

[boscoe]

 

[Edchris177]

This should jump out at you. From at least 1991 to 1997, possibly much earlier & later, the blocks have not changed much.
That is where the thermostat is on those years. If it’s not obvious in relation to those diagrams…maybe your engine is a far different vintage?
Maybe post acouple of pictures. This should be really easy to find.
Here is a diagram of water flow on the 40-90 hp motors. You should be able to reference it to yours & find the thermostat.

 

[Luke M]

thanks all, it is definitely staring straight at me ... thanks for your assistance