350cu in 260 hp engine is over heating, when idling? turned it off now it won't start? any ideas?

Question

runs up toward 180, when running, over heats when idling, I shut off the engine, now it won't start?

1980 bell boy ski boat, 350, cu in 260 hp, omc inboard out board

thanks

Answer 1

Depending on how long you ran it when it was overheated, you may have damaged the engine.  In any case, it sounds like you lost some of the vanes on your water pump impeller OR you have an obstruction in your cooling system.  Best to have it checked out by a reliable mechanic. Good luck.

Answer 2

If the boat only reached a temp of 180 no severe damage should have occoured. Normaly my boat runs about 140-150...I think that most boat thermostats release about 145 so 180 is not severe. Speaking of that have you checked the thermostat to make sure it is not stuck. If not you are likely to have a bad impeller. This requires a trip to the local marine repair shop unless you are knowledgable with the internals of a lower unit. As far as it not starting is the engine cranking over? If so check all the basics, are you getting spark? gas? air? if all three check out then you should be good. The heat may have possibly stuck a ring which i doubt but it is a possibility..take and spray some type of lubricant into the plug holes on top of the cylinder(pref. marvel mystery oil)...let it set for a while this should free up any seizing that has occoured. Good Luck! Hope I have helped.