[Apex]

Ok, I hear this question time and time again, and I just really want to educate people on this.

Fuel as we all know comes in different octane levels. Why are there different levels? To accommodate for varying cylinder compression ratios.

A 250 was designed for 87 octane. If you run less, you are leaving your self open for detonation which can cause engine damage. Fire off the mixture prematurely due to heat, and your compression stroke turns into a power stroke, trying to force the piston back down, when it needs to continue up. Bye bye piston.

Now people for some reason think that running a higher level octane yields a higher level of performance, or it is a cleaner gas.

For the most part, this is false. Granted, some gasoline's put little additives into the gas for the higher level grades, but it does not yield a gain in performance. A bike like ours (or cars for that matter) which is designed to run 87 does not like anything else. The higher level octane, the slower the burn. The slower burn is typically compensated by a higher compression ratio to offset the burn rate.

Add high octane to an engine designed for 87 and you will lose performance. The gas will not burn as quickly or efficiently, thus causing a loss of power. So if you want to lose a little HP, add some higher octane fuel. The losses of not running the recommended gasoline in an engine far outweigh the possible gains (if any).

Typical fuel system treatments treat a certain amount of gas. Mathematically figure out the conversion for our tanks, and add that every 3k miles or so. I think that will be better in the long run than running a higher octane.

Run the recommended fuel. Your pocketbook and your bike will thank you