Leaded or Unleaded fuel?

[johnnymac59]

I have recently bought a 115HP Johnson outboard mid 70's and originally I guess it was meant to run on leaded fuel with a 2-stroke oil. Is it ok to run this on unleaded fuel with a 2-stroke oil mixture or should I be adding a fuel additive too??

 

[DJ]

Re: Leaded or Unleaded fuel?

Johnny,<br /><br />Outboards do not care about lead. Lead was for four stroke engine valve lubrication. It plays no effect on two strokes, other than octane. MTBE/Alcohol has taken care of that issue.<br /><br />Any quality gas with 87 octane is fine mixed with a good quality TCW-3 rated outboard oil is more than sufficient.<br /><br />The key is the oil. TCW-3 ONLY! NO CHAINSAW (air cooled) OIL.<br /><br />You may want to read this. See link below.<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=36;t=000006

 

[Dhadley]

Re: Leaded or Unleaded fuel?

And they -- very quietly -- took MTBE out sometime around 2001 apparently. Interesting.<br /><br />When the lead was removed the OMC engineers sort of panicked. I'm sure others did too about their own 2 strokes but as it turned out, the sky did not fall in 2-strokeville.

 

[johnnymac59]

Re: Leaded or Unleaded fuel?

Thanks DJ, Much appreciated.<br /><br />John

 

[DJ]

Re: Leaded or Unleaded fuel?

Hey, DH,<br /><br />MTBE hung on for a while out here in the desert Southwest. How I don't know, might have been politics-ya think? Must have been a "California" thing.<br /><br />Anyway, octane is octane, that's all outboards care about. <br /><br />You agree?<br /><br />By the way, Johnny. When Dhadley speaks-book it.

 

[Dhadley]

Re: Leaded or Unleaded fuel?

Yep, the correct octane is what 2 strokes are sensative about. They dont like too little or too much.<br /><br />And DJ's right about the political thing too. Its funny how congress and the EPA made a big deal about MTBE when they figured it was the answer but how little they talked about it when they realized it was pretty harmful.

 

[Scaaty]

Re: Leaded or Unleaded fuel?

Make sure your timing is on the nose, or touch retarded for the junk the sell as gas now. Aluminum pistons love octane or look for daylight

 

[jim dozier]

Re: Leaded or Unleaded fuel?

The problem with MTBE is that it is relatively water soluble. When the underground storage tanks start leaking as they inevitably do (especially the older single wall ones) the MTBE dissolves in the groundwater much faster than the other less soluble components of gasoline and it can travel more quickly underground. It has ruined more than one public water supply.