had a little time to work on the boat this evening.

I pulled the raw water pump assembly. the impeller looks fine to me. no pieces missing. The wear plate shows signs of wear, but feels smooth to me.
lots of water in the inlet and outlet hose, so I think it was probably working fine. I have a new raw water pump coming, so I'll replace it anyway, just to rule it out.

I also pulled the thermostat. cleaned the housing up. I also ordered a 140 degree stat from merc. I think I had to many holes in the 160 stat that it probably wasn't even opening. I plan to put the 140 back in with no holes and see what happens.

I also pulled the alarm sending unit, cleaned it up, and felt around through the intake into the head. No obstructions that I could see/feel. put the sending unit back on.

I have to believe I have a water pressure issue where to much water is being diverted to the exhaust instead of the motor. I'm thinking I should have left the piece of hose inside the crossover over hose. I plan to find another way to reduce the crossover hose as well, and try to force more water into the motor.

when I pressure tested my oil cooler I checked it out real good, and there was nothing inside blocking it. so unless something somehow got in there in the past 2-3 hours of run time I am pretty sure its good as well.

What kind of water psi should I see at 3500 rpm and brought 40 mph? Last weekend was 8-10#. That seems a little low to me, no? I will also check all the hoses for kinks again.

my last boat had a crossover over as well, and I had the exact opposite problem. to much water psi, and hard to get the water/oil temp up. I fixed it by adding a water psi relief valve, and oil thermostat.

Go to home depot with crossover to riser hose. Get a wood dowel pin that slides in snug but removable. Get a drill and start experimenting. You might wanna cut a bunch and pre-drill diff size holes. I would put the plug in at the riser, not intake manifold. That way it can't slide in to the middle of the hose. Take along a 2 foot piece of something to use as a ram rod to remove plug. Then when you find the size that works, make one out of something other than wood.

Hour and half of run time today. No alarm, and everything ran good.

stretched her legs a little today. 15 min at 3500-4500 rpms. Oil temp 225. Thats ok isnt it? Water temp was 125ish. (140 thermostat).

Got some soot on the transom and plugs are a little on wet side so probably need to lean it out a little. Runs good though.

Too rich wastes gas. Too lean wastes pistons...

Your engine builder may have wanted it too run a little rich. Better rich than lean.

Was the carb set up and adjusted with the boat in the water or engine on the stand?

I bought the carb after i got the motor back. Its a quick fuel 850.

I think the floats are still a little high as well.

oh ok cool, thats a good carb, but yeah it needs to be in the water to adjust the floats...

Put a ball valve in line