Re: Confused about which oil weight to use
(edit: I replied from the original post on your over heat on page 1, didn't see the previous replies until just now. I repeated a couple things, but also added a couple. No matter what you need to get to the bottom of this before using this engine again... if its still usable.)
Cooling circulatory issue. Raw water cooled? or Freshwater cooled?
If raw water cooled, I'm not sure, but I believe there is a thermostat that provides coolant flow to the cylinder water jacket... it bypasses what it doesn't need to the exhaust (so you'd still see flow even though its not being circulated through the engine). I'd bet that thermostat stuck closed, or failed to open enough for whatever reason. Line blockage post the thermostat is also a candidate as severe corrosion in the water jacket itself that can break free and plug the flow downstream so it prevents circulation.
If freshwater cooled... the raw water outflow from the heat exchanger does the exhuast cooling so it would still show in the exhuast. In this case, circulation was prevented in the freshwater side of the system (water pump, inoperative thermostat, pinched of or blocked line (blocked is unlikely though in the freshwater side of the system, but a pinched line due to fatigue is still possible). Its also possible in this case the the heat exchanger is tired... but unlikely.
Does your system include a temp gauge? Worth their weight in gold! Also some systems have a high temp shut down built it... if yours does...it must have failed too.
Obviously I am not looking at your engine... but from your description, its what it sounds like a thermostat failure or blockage to me or at least a good possibility of it.
Even though you replaced the starter... seizing likely scored the cylinder walls... while it may still run... it will start taking oil and have a reduction in power. Time for a rebuild or at least a refresh honing and new rings on the piston.
Good luck, Dave
1980 Seafarer Swiftsure 30
1978 Bayliner Buccaneer 270 (now sold and being restored in FL)
1962 SeaMac 14' Plywood Runabout, mahogany decked, with 1959 Evinrude 35 Big Twin (owned since age 17, I'm now 60)
Last edited by dem45133; 08-03-2013 at 10:09 AM.