Need Help With Overheating Ultra LX

[steve45]

Took the 'Skis out on our lake today, they performed perfectly.

Do these things have a thermostat?

[blakegjones]

I’m confused. What fixed the problem?

[steve45]

I’m confused. What fixed the problem?

I don't know. I was never able to find any blockage. My guess would be something like a small stick that dried out, shrank, and came loose.

I did blow gently back through the pisser (by mouth) and had little resistance.

[smokeysevin]

I did blow gently back through the pisser (by mouth) and had little resistance.

I know we are all friends here but maybe don't mention that outside of the forum...

Sean

[blakegjones]

I know we are all friends here but maybe don't mention that outside of the forum...

Sean

Haha!

Anyways glad it’s sorted. Really is strange though. No thermostat that I’m aware of. Only part of cooling system I haven’t opened up is in the oil cooler and doubt there is one In there.

[grumpy_steven]

You'd get a lot of resistance if you tried to blow through my pisser.

[steve45]

OK, ha, ha, ha!

I was just following Blake's advice.

I couldn't find any reference to a thermostat, but Yamaha uses them on some of their 4-strokes.

[grumpy_steven]

There is no thermostat on the Kawi motors. But you are correct, the Yamaha MR-1 motors do have a thermostat.

Check the brass fittings on the waterbox. The openings are very small, and can easily be blocked by debris.

[blakegjones]

Check the brass fittings on the waterbox. The openings are very small, and can easily be blocked by debris.

Yes that is very true. I swopped that brass fitting on the waterbox with the tiny orifice with a connector that has a slightly bigger diameter and used a hose with a smaller ID to add to the pressure loss that I removed by swopping out the small orifice.

I found bits in that small orifice every single time I looked at it which is what made me change it out.

[steve45]

Thanks, Blake! I'll take a look at it.