fuel usage in 74 140hp merc engine.

[kleinboy]

I have a 1974 140hp 4cyl. engine in my boat that I just aquired.<br /><br />My question is what is a safe fuel to use today in that year engine. The manual says to use only "leaded type fuel", but that type fuel is not available anymore.<br /><br />Also, is it safe to use a lead substitute?<br /><br />Any help will be great!!!

 

[Trent]

Re: fuel usage in 74 140hp merc engine.

Current models say to use 88 Octane fuel.

 

[kleinboy]

Re: fuel usage in 74 140hp merc engine.

do I need to use a lead substitute in this 1974 model 140 horsepower mercruiser engine?

 

[Bob_VT]

Re: fuel usage in 74 140hp merc engine.

It certainly will not hurt. The main differance between leaded and unleaded engines was the valves and seats. The lead lubricated the valve seats. I would use some just to be safe.<br /><br />Bob