15 MSH 2 Stroke Thermostat Question

[Fishheadbarandgrill]

Just bought an aftermarket thermostat on Amazon. The stat fits nicely but the top of the stat is larger than the OEM, therefore the metal gasket wont fit over the top of the stat. Problem?

Thanks,
Bob

[boscoe99]

I would think so. Only operation of the motor with the improper part installed will tell.

[robert graham]

Is anything wrong with your original thermostat?....maybe clean it and test it in a pot of hot water....if still good then just re-install it....

[pstephens46]

I don't mind aftermarket stuff. I might pass on thermostats and water pump kits however.

[Fishheadbarandgrill]

I've ordered an OEM stat... Not happy with how it fits.

Bob

[TownsendsFJR1300]

I've ordered an OEM stat... Not happy with how it fits.

Bob

I think (and may very well be wrong), but isn't there a rubber seal that actually
goes around (and envelopes) the outer edge of the OEM thermostat?

Part #23: http://www.boats.net/parts/search/Ya...ASE/parts.html


.

[robert graham]

I think (and may very well be wrong), but isn't there a rubber seal that actually
goes around (and envelopes) the outer edge of the OEM thermostat?

Part #23: 2006 and Later 15MSH Yamaha Outboard CYLINDER CRANKCASE Diagram and Parts


.

Yep, my C90 thermostat has a rubber seal ring around it's circumference....
I believe that with a bit of checking and cleaning on a yearly basis the Yamaha thermostats will last for many years....

[TownsendsFJR1300]

I believe that with a bit of checking and cleaning on a yearly basis the Yamaha thermostats will last for many years....

I got 10 years out of mine (still worked-never cleaned out of the engine, but religiously flushed). It was looking ragged.

Thermostat, anodes, PCV rubber were replaced, spring & valve cleaned...