Yamaha 8hp Cooling System

[sutor623]

I have a 1985ish 2 stroke yamaha 8hp. I have a question about the exhaust reliefs. Replaced the waterpump on it and it pumps water well. The block stays nice and cool, and I ran the motor on muffs for 20 minutes at different speeds.

I get water coming out of the prop exhaust as expected. The exhaust relief holes just under the motor cover on the back of the motor are puffing out exhaust gasses, but no water, even at 1500 or so RPMs. Is this normal? If not could there be a blockage upstream of the relief holes because the motor is cooling very well. I ran some weedeater string up there and nothing changed. This is a friends motor and I want to be sure to send him home with this thing in tip top shape.

 

[sutor623]

Hey guys need some guidance here. How can you tell if the thermostat is opening in these motors? I have plenty of water coming out of the thru prop exhaust, even when the motor is cold. I think the thermostat may be missing but I don't want to pull the head plate off because the bolts are all corroded with salt. I assume the telltale hole is BEFORE the thermostat so thats not a good indicator if the thermostat is opening......

 

[99yam40]

My c40 does not put out water from the idle relief ports either. I worried about it when I 1st got the motor used, but I have not had any problems from it for 3 years now operating like that.
Friend had a C60 that had a mist come out at idle.
Nothing like the old Johnyrudes, they dumped lots of water out