1981 140hp evinrude OB/ fuel mix with amsoil usage/ sea foam yes or no!!!!!

[old141fe]

a new member i need help, just aquired this jem from my dad baught him anew boat, i want to make sure i get off on the right foot i have a good maintiance background, so my question is what octaine to use containing eth and what mixture. second should i use seafoam in the fuel as well. please advise thanks Huck

[Faztbullet]

87 octane is fine with that motor and no more than 10% ethanol. Try not to use the ethanol fuels but with fuel prices climbing its not going to be a option. If you do run ethanol make sure you do not let fuel set in carbs or tank for a extended period due to phase seperation and possible degradation of the fuel line,just add as much as you think you will use. If you stay with the Amsoil you should not have to add Seafoam except at end of year for cleaning up the exhaust.

[SparkieBoat]

I run the cheapest 2 stroke oil I can find and add sea foam every 2 or 3 tank fulls...no problems so far