A week of high temp will vaporize fuel from the carb and leave the bowls dry.Results in excess cranking .If you have an electric pump you can add a momentary switch to prime the carb usually installed in the eng compartment .
You do always open the engine compartment to sniff and look first ,right?
Most issues are caused by the steel ends crimped on the cables instead of copper ones. Also the ends of the cable where its crimped are usually black from corrosion. Cutting back to clean copper and recrimping copper connectors solve the voltage problem
get a better mechanic. could be just some leaking valves from water intrusion or holes in the piston at its worst. Only by removing the head will you be sure
just a guess the tach was causing an issue running the motor,does the tach work now?
Blue in that area is the oil pressure sensor and the Blue/white(tan) may be for the "no oil pressure sender"
In most cases. there is the main battery cable , then a red,or red/purple .This is the boats main power connection,then the yellow/red wire to the solenoid Some use an additional wire from the other small post on the solenoid to provide voltage to the electric fuel pump for cranking
disconnecting the battery cable lead can do it causing the alt to run wild. dirty connection ,fittings, corrosion,battery switch and connections neg cable at engine loose ,corroded, etc Also a open winding in the alt can do the same.
alpha Gen II housing that was taking on a lot of water. Suspected of using regular bottom paint instead of outdrive paint over the years. What do you think?