I have an 02 Vinson. I have been using 87 octane almost from the day I bought it. I was wondering if a higher octane would affect performance......anybody out there know?

 

No,
in fact you would lose power if you used higher octane in your stock enging.
The only reason to use higher octane is when your highly modded engine needs to run cooler, so you won't burn it up.
Unless you are getting detonation, use 87 octane.
Lots of heated threads on this topic, do a search.

 

Absolutely, Megacrash is right. Fuel suppliers love people that don't know any better and buy a higher octane than necessary.

 

Compression dictates octane.
Find out what compression your machine has and run the appropriate fuel.
Maybe you will need an 89 octane fuel. I do agree w/the others thinking that high test is not needed,altho,pump gas is pretty crappy stuff to pour into our machines. [img]i/expressions/face-icon-small-happy.gif[/img]

 

O.K. lt 80....how do I test compression? The thing is, I've had this machine for a year now...and it seemed a wee bit quicker last year...maybe its just me. Thanks

 

You test compression with a compression gauge. Cost you about 20 bucks. But, there's no way to simply test compression and know what octane fuel to run. There are many other factors, such as squish, dome design, bore, ignition, etc. All these affect your engine's propensity to detonate or not detonate. If your machine is stock, run what's recommended for it (dealer will have this info if you don't have a manual on a used machine). If you have a modified head and/or other parts check with the aftermarket co that makes them, they'll be able to tell you or at least guide you.

IMO, you'll never feel the difference in fuel octane with the a$$ dyno (seat of the pants feel while riding). Some say they can. I say BS.

 

Quicker last year could be: wore piston/rings or valves possibly being out of adjustment.
Less common things could be: belt wear or maybe a clutch problem.
You'll figure this out [img]i/expressions/face-icon-small-happy.gif[/img]

 

Hey Lt 80....you mentioned pistons/rinds and valves....could they really be out of whack after only a year? Thanks

 

The prior responses are correct- higher octane than necessary actually results in less performance, although it is a small amount. One consideration for any small engine (less than automotive size) is fuel quality. "premium" grade gasolines have a fuel stabilizer added to them, the cheapest grade does not. Todays gasoline has a very short shelf life without some kind of fuel stabilizer added to it. If you sometimes have the same gas in your machine for a month or so, it will start breaking down and gumming up the carburetor. This can cause a properly jetted machine to not start, run poorly, or worse run lean and possibly result in burning a piston. It is most pronounced in a 2 stroke but can effect any small engine. If your machine is going to be sitting for a period of time, it may be a worthwhile investment to use a premium grade,( with the lowest octane possible) or you can use a stabilizer like Sta-bil, or other brands. For machines that sit for long periods of time (over the winter or summer season) i use both. A lot more problems are caused by bad gas than people recognize. There are ways to compensate for the lost performance from using higher octane fuel than needed,( such as advanced timing) but they are best left to people who have the expertise to meddle with such things.

 

Glen, you state pemium fuel has a stabilizer added to it. I've never heard this before, do you have specific or inside info on this? I'm just a skeptic and doubt the fuel companies are adding anything that would cost them money without touting it as an added value.