What fuel to use in new outboard?

[Guest]

Bought a new 2-stroke Yamaha 60hp motor last year. Should I be using Premium Unleaded or is regular fine?

[Esoxmn]

check your owners manual, but i would say premium, non oxygenated.

[This message has been edited by esoxmn (edited 05-20-2004).]

[united jigsticker]

My 2002 50 hp 2-stroke Yamaha owners manual suggested non-oxy 87 octane.

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Good fishing,
UJ
[email protected]

[Gus]

I've never found non oxy 87 octane only 91 non oxy. Does anyone know where to find 87 non oxy?

[New Yankee]

I've wondered the same question - premium fuel or regular for sometime and have found opinions strong on both sides of the coin.

Searching the web, I read an article that made some sense. Premium fuel has spark retardants to reduce the 'ping' or 'knock' that is known as pre ignition. These fuels can be compressed to greater pressures (remember the old muscle cars with 11 to 1 compression ratios) and not ignite at lower temps to achieve their performance.

If most of us use off the rack equipment, the added octane could cause incomplete burn in the combustion chamber causing some build up particularly in 2 stroke motors. In 4 strokes I'm not sure the build up would occur but the extra $$ spent would be wasted if the engine didn't require the extra octane to achieve normal performance.

The above being said, I've had as many mechanics and dealers tell me to use 87 as they have premium. The best solution in my opinion is to use a good quality 87 and don't let it get older than a couple three months.

Brings up the age old question - do I keep her full or run it dry at seasons end? Probably as many opinions on this as well - use what works for you (I keep my stuff full and treated and at the start of the season try to add as much fresh after each use)

Thought I'd chime in for what it's worth!

[Guest]

Stupid question... What the heck is non-oxygenated fuel?

[bbells]

No alcohol or similar. The pump will say "non-oxygenated, for offroad use only, etc."

[Justfishing]

Octane is the measure of the iginition point of gas. If the gas is igniting from compression then you have pinging or preiginition, like a diesel engine, and need higher octane. The higher the pressure/compression the higher the octane required. High performance engines have higher compresion and need high octance. Carbon buildup will increase your compression and can cause preigintion so run Seafoam or similar to eliminate carbon buildup.

In the old cars some people felt they needed to run premium to prevent knock. This was a self fullfining prophecy becuase incomplete combustion lead to carbon which lead to higher compression and preiginition.

If you can't run on the recommened octane then you may have carbon buildup or another problem.

With ther current oil shortage run the lowest octane possible. It takes more oil and refining to make the same amount of high octance. Thus all the people running high octane-if not needed- are contributing to the problem.

[Guest]

Heres a list of places to get non-oxy gas around MN. I didn't complie the list...

http://webpages.charter.net/trenville/Non-Oxy_Gas.pdf

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-FNC

"get on the natch"

[BarryG]

Where did you find that list? Is it available for other states? Thanks!