Higher octane is harder to ignite. Thats why high compression motors use high octane gas, to keep them from innighting the fuel from compression(like a diesel does). So there is no reason from that standpoint to run higher octane. Another factor is that higher octane fuel is more refines so more of the oil is removed in the process, meanig your top end does not get the extra oiling it could with lower octane.

 

because ethenal blended fuel has alcohol in it, it will be slightly leaner. You may get some drivability problems, like hard starting or exhaust popping on decell.. The owners manuals state to not store a quad with ethenol in it, it goes bad sooner than pure gas. But if youre gonna fill up, and use up the tankfull in less than a month, it wont hurt to use ethenol.

 

My theory is gas loses it's octane rating over time. If you buy premium and let it set a couple of weeks, you'll probably still be over the required amount whereas if you buy 87 and let it sit....predetination is risky bitness! [img]i/expressions/face-icon-small-wink.gif[/img]

 

I use Stabil too.

 

i ran 87, 89 and 93, bike pinged at 87, ran sluggish at 93 and runs perfect at 89, just need to try them all out

 

Octane controls how fast the fuel burns or controls the rate of "flame front propagation" inside the combustion chamber. The higher the octane number the slower the fuel burns. The lower the octane the faster the fuel burns. When the fuel burns too fast it causes the engine to "ping" because the piston may not have passed TDC at the time of combustion. Combustion needs to occur when the piston is between 10 and 20 degrees after TDC. If the octane level is too high the fuel burns too slow and combustion may not occur until the piston passes the ideal 10-20 degrees ATDC.

High octane fuel is not as volatile as lower octane fuels and is hard to ignite in very cold conditions due to the lack of the fuels ability to vaporize.

In most cases, there is no advantage to use a higher octane that the level recommended by the manufacture.

 

In the Rancher run 87. I buy 87 pump gas and add enough Klotz octane booster to it to bump it up just a little. I don't really feel like I need more octane, but I add the booster because it has gas preservative in it, just in case my fuel sees long storage.

For example, I primarily ride the sport bikes in the desert during the cool months, and the utilities in the mountains during the hot months. So my utes might sit around little used in the winter, and my sports sit around little used in the summer. So, some gas preservative is in order.