Maco...your right.....it could be the simplest thing, we just can't pinpoint the bastage. When I say we, I mean, (me & the crew @ Tripp Marine, Wesport Ma) are having a hell of a time with this pig.
I've replaced the following: <in this order>
Complete Engine Tune-up
Replaced all hoses on engine.
Replaced Thermostat
Removed Thermostat
Did the bucket test (making sure it was pumping the water as it shoud be)
Tested the Sensor Guage
Took an actual temperature reading from the engine itself
Replaced Risers & Riser Elbows & thouroughly cleaned the inside cavities out
Replaced WaterPump-Impeller Kit
Replaced the entire gear mechanism in the leg unit
Nun - when I had the risers replaced, I personally cleaned out the manifold cavities scraping any loose 'scale' from the walls. I'm pretty sure I got most of it, but you have a point...maybe due to it's age...it built up again or fell from spots I couldn't reach ??? The only problem with that theory (blockage) is that is doesn't overheat at a low RPM. So if it was being restricted, I'd imagine it would be restricted even at a low RPM level. My strongest guess is that the impeller doesn't draw enough water in at high speeds so it takes the hotter water longer to get out...but what do I know
I'm unfamiliar with the low pressure hose though??...two hoses pump in, two hoses pump out...which is the low pressure hose, the two that pump out??
The engine
was running fine...last trip out, it stalled and hasn't started since. I'm afraid she may have seized up on me. I didnt' have the temperature pegged, but now she just won't turn over. I noticed the Battery gauge is now reading 0, telling me either the battery suddenly went dead by itself
or the engine drained it because it had seized up. I'm headed down tomorrow with 2 new batteries, I'm going to try a few more things...then she's coming out again...and back to $$$ Tripp's.
$%@$%@%^^&@%@#$%^&%^$$#T# BOATS!!!