it would not turn over, or it would not fire. Two completely different issues.
since you typed it would not turn over.....check the oil for water. sounds like water ingestion from failing exhaust manifolds.
I personally consider any boat under $10k a project until proven otherwise
Most leaks are simply rivets needing rebuking.
Floor and transom is a weekend job in a tinny
Tilt and trim fluid is similar to ATF. The pump will run on SAE 30 weight, hydraulic oil, ATF, tilt and trim fluid or even diesel fuel.
Over the years, the same Oildyne 108 pump has been spec's with about 30 different oils .... They all work
3 local companies are doing EV boats. 2 burned when the batteries caught fire from getting wet, another has been towed in more than I have ever been in the last 15 years
The GM 3.0 4 cylinder was NEVER used in an automotive application.
It's a GM industrial motor used in forklifts, gensets and trash pumps. It was also used in boats
wait until temps are below 80. with the current warm temperatures of Florida and Georgia, if you mix a hot mix, gel can literally go up in flames due to exothermic reaction to the MEKP
I couldnt tell you if I used their 925 or the 9.