Jeffplease advise

[Paulette]

" Thanks for your help in loca

" Thanks for your help in locating the idle adjust on our 1975 Merc 40hp. We will try that. We had problems with the engine getting hot this season and the throttle seizing up. The water stream coming out of the engine was scalding. After adding a little oil to lower unit and a little extra oil to the gas...and a change of spark plugs, engine and water is running cool. Not sure why. Should we be adding lead additive to the gas since the engine is an older model? Higher than 87 octane? Thanks again! "

 

[jeffery]

" Paulette, I can't explai

" Paulette, I can't explain why your motor ran hot and now cool. If your not sure of the age of your water pump and thermostat, have them replaced. I do that on any engine I'm not familiar with. Even if everything works perfectly. If your motor overheats it will be toast, period.
You should be fine on ordinary pump gas. I would recommend 89 octane. Use a good brand of 2 cycle oil. Merc- johnson- evinrude oil is very good. The cheap stuff lubricates fine, but it leaves a lot of ash after it burns.
Can you elaborate on the throttle seizing problem?
Jeff. "