Question about gas ...

[chattfisher]

I've got a little 15hp Johnson 2-stroke that I am bound and determined to keep ethonol free, but it's getting harder by the day. I recently filled up at a gas station near my house that had ethonol free, but only in premium. How will that effect the performance of the motor? The reason I ask is because I took it out that morning and had to choke it the entire time for it to continue to run. I'm assuming that I need to adjust the carberator for the higher octane, but I may be making too much out of it. Is there anything I need to do to compensate for the the higher grade gas?

Thanks in advance.

 

[Hair Jig]

Premium fuel didn't cause the motor to run poorly. Something else is amiss. Carburetor adjustments on "consumer" motors are not required when switching from one pump octant to another. Especially with one of that size. I sent you a PM with the appropriate actions (in my opinion).

 

[chattfisher]

Thanks, 'Jig. Was just thinking about it and I think I swapped out fuel lines that day, too. Probably the problem right there.

 

[Hair Jig]

Good possibility. emoThumbsup

 

[wrechin2]

Running a higher octane than needed will cause a slight power loss due to the slower burn rate of the higher octane fuels if it is designed to run on 87. Nothing needs to be done unless you wanted the most out of the engine you would have to make some adjustments but on a engine that small I don't know if it is worth it or noticable. Depending on what year the engine is, you may need to run 93 anyway as you did not mention the year of the engine. The octane was a lot higher with leaded fuels in the late 60's and through the most of the 70's and the engines were designed to run on the available fuel. Just my experiences.

 

[chattfisher]

Thanks, James. The engine's a 95, so up to this most recent time I've been running 87 octane and it's done fine. I really think it might have just been getting too much fuel from the other fuel line I used. Gonna go back to my original and see if that changes things.