Engine Temperature and Engine stall after turn

Hi -- Brand new to this forum!!!

I have a 1976 Mercruiser with 605 hours -- yes that is correct. The engine has been bullet proof and exceptionally maintained.

Two questions.

1. What is the normal operating temperature -- currently after a normal cruise the temp is about 155-160. When I run it hard it will get up to 180. The temp returns to the 155-160 range upon idle. I have had the impeller replaced a few times -- from lack of use -- and it seems this is a little high.--- Thoughts?

2. After a hard run WOT for 20 minutes if I make a sharp right (starboard) turn the engine may sputter and stall -- it starts right back up -- Any thoughts?

Other than these items everything with the boat (Browning Mustang II) has been great. As a side bar - with the exception of routine service a starter and trim pump and just last year a new prop-- have been the only things replace on the engine. In regards to the boat -- the only item that has been replaced has been the carpet -- Inadvertent gas spill that pulled the orginal carpet up. Everything thing else is orginal


Thanks in advance

3 pointstar

a little bit warm if its raw water cooled....but someone may have changed the thermostat. If it is that old, you better start budgeting for a set of exhaust elbows as they are on borrowed time, especially if original.

The 'sputter and stall' may be a fuel delivery issue. If the fuel pump is original, it probably isn't as efficient as it once was. Could also be due to the physics involved.

which engine/carb is on it? How much fuel was in the tank and tank's location on the hull? how oftern does this occur?

The boat is running good temp wise, see after all these years you have scale buildup in the water jacket. Leave it alone it is normal for a old piece of iron you have. If the temp should ever get close to 200 then you have a blockage problem. But that is for then this is for now leave it alone.

Now to your cutout problem, what is missing at that exact moment it happens. Fuel or spark, see your ass u ming it's fuel. Don't fall into that trap.

Bring a spare spark plug when at the exact moment it happens again pull a plug wire and stick the spare plug in the wire hold it to the block and crank the motor.

See if your missing spark. if yes you narrowed it down. Fuel problem then i would think the float in the carb. Getting stuck up maybe not allowing fuel to the metering rods, maybe.

The fuel filter in the fitting that enters the carb clean ? All other filters clean?

The anti-syphin valve clean and working? The fuel pickup tube clean?

Keep us posted.