KZ305 won't start

Might be missing something here, but how could high-octane be bad for the bike? Yes, it is 110 race fuel, just used it because we sell it here at the shop, and it's easier for me to do that rather than to drive up to the gas station and fill it.

Don't plan on running it all the time, just this first tank. Tends to clean things out nicely from my experience. Heck, I'll even run a tank through the lawn mower every now and then. Haven't had any problems yet. Only problems I know of using leaded race fuel is with catalytic converters and O2 sensors.

high octane fuel in an engine that doesn't need it, tends to cause carbon build-up because it doesn't burn as rapidly (and thus generally, not as hot) as lower octane. This changes in high comp/advanced timing/high boost situations.

LOL, I've seen a lot worse carbon build-up from cheap gas than from race gas. Anyway, either way, I'm not planning on running it all the time. Like I said, it was just easier for me to step outside and fill it up from our tank than ride to the gas station. Thanks for the heads up though!

Oh, and if anyone has any more ideas, shoot. As soon as I get a free chance I'll be setting it on TDC and pulling the valve cover. All I can figure that could possibly be wrong with it is timing. It's got fuel, spark, and compression, only one thing left I think! :S

Post edited by: Joel07, at: 2006/08/03 09:11

Joel, 110 octane gas will hardly burn in your bike. Octane inhibits combustion. In other words, regular 87 octane gas ignites more readily than 90 octane gas, much less 110 race gas. The point of octane is to keep VERY high compression engines from pre-detonating. Your 305 is not a very high compression engine. In fact, it is a low compression engine. When a bike runs on fuel with more octane than is optimal, combustion is incomplete. This leaves carbon in the combustion chamber; on the valves and piston crowns.

After reading the comments in this thread, I would first replace the intake manifolds as they create and excessively lean condition which will make starting difficult and the cold air coming in a crack in a manifold will focus on your piston crown and burn a hole in no time.

Next, if the bike is getting gas, the plugs will be wet when you crank the engine. Are the plugs wet? If the bike is getting gas, then the problem is spark or the timing of the spark or compression and AGAIN, the main reason for compression loss is lack of valve clearance. You have gotten the info needed to get you on the right track so hopefully you will take some of this advice to heart. Good luck...