Yamaha c60 (1996) Pressure relief valve/poppet

[jimbohig]

I have what are common symptoms of Poppet problems. ie Overheat buzzer goes off after idling for a while. Very strong Jet of water from tell tale. No problems at higher revs,
Checked the thermostat is working. Cant find anywhere online where the pressure relief valve is on this model. Does it even have one? If it does where is it?

[TownsendsFJR1300]

I don't see a poppet valve on your engine(there's two C60's, neither shows one):

https://www.boats.net/catalog/yamaha...nder-crankcase

When's the last time the WP was replaced?

[rodbolt17]

the 60 and 70 two strokes used a low pressure high volume system. no pcv.
also you cant use a water pressure guage.

[jimbohig]

Thanks I studied those crankcase pics and I couldn't find one either. What is a WP? is it Water Pump?
I just bought a new impeller but have not got round to fitting it yet. The motor has been used very little and is very clean and the tell tale is very strong.

[99yam40]

WP he writes about would be the water pump.

low use motors can have issues do to them not being run often.
hope yours turns out to be a good one.

I myself would replace the Water pump with a kit not just an impeller and inspect the housing for any signs of melting/distortion

[TownsendsFJR1300]

WP he writes about would be the water pump.

low use motors can have issues do to them not being run often.
hope yours turns out to be a good one.

I myself would replace the Water pump with a kit not just an impeller and inspect the housing for any signs of melting/distortion

+1, ^^^, about the Water Pump and also putting an entire kit. Doesn't take much leakage to over heat.

You also want to make sure the outer housing is not warped (from excess heat), etc:
Part #25, https://www.boats.net/catalog/yamaha...casing-drive-1

[DennisG01]

Agree with doing the kit (or at least closely inspecting housing and wear plate). I'm still relatively new to the nuances of Yamahas, but I've seen many times (first hand) on other engines where the reason for an overheat at low RPM's, yet fine at higher RPM's, is due to a slightly scored (doesn't take much) housing/wear plate. That's not to say that this is your issue, just that it is a viable reason for the issue.