synthetic oil

[Macca]

Gooday fella's<br />as some of you know I'm new to the boating world so here's another decision I'm not sure about. I have just purchased a 1975 135hp 2 stroke evinrude outboard which has had leaded fuel run in it most of it's life until it was no longer available and then lead replacement fuel was used.When I purchased the boat the marine dealer advised me to go to premium unleaded fuel as it has a higher octane level which I did.Mineral based 2stroke oil has been used all along as well however now I here from different people that synthetic 2 stroke oil is all the go. Is this right in an engine this old or should I stick to the mineral based 2 stoke oils.<br /> Thank again, Macc***

 

[JB]

Re: synthetic oil

G'day, Macca.<br /><br />When tetraethyl lead was used in gasoline, it was to raise octane and to lubricate valves in auto and truck engines.<br /><br />Two stroke engines need neither high octane nor valve lubrication. Most outboard makers recommended unleaded gasoline even when ethyl was common.<br /><br />So, first of all, you do not need high octane. Regular unleaded (91 octane by your method) will do just fine.<br /><br />Second, so long as the oil you use is rated TCW-3 it will suffice.<br /><br />There is much disagreement on these issues, but no requirement by makers to use premium fuel or synthetic oils.<br /><br />Good luck.

 

[rickdb1boat]

Re: synthetic oil

On a 27 Year old engine, I would stick with TCW-3, Non-Synthetic!

 

[Macca]

Re: synthetic oil

Thanks JB and Rick, I'll leave the synthetics alone and also get back to normal unleaded<br /> All the best<br /> Macca