91 RM250 throttle stuck????

[soniccascade]

I just had the weirdest thing happen to me. I was working on the bike, and started it up to idle for a few minutes. I revved it a few times, and then a bigger rev a minute or so after. All of a sudden the bike got stuck at a high RPM! I mashed down the kill switch, but it did nothing. I even went as far as shutting off the gas, pulling the gas hose, and even pulled the plug wire. The damn thing still ran! The only way I was able to get it to shut off was to put it in gear, hold on for dear life, and stall it by jamming the tire in the ground and dumping the clutch. After it shut off the radiator spewed coolant everywhere from the upper vent, presumably because it got too hot.

Does anyone have any idea what the hell happened, and how the bike continued to run with no spark?? The throttle position was closed and fine too, so I have NO IDEA what is going on.

Thanks DRN'ers.

 

[Gibby]

I think it is evil!!!

 

[soniccascade]

Thanks for your constructive reply.

 

[YZ165]

What were you doing to the bike before this happend? Carb Clean? Throttle cable adjustment? YZ165

 

[soniccascade]

I had rinsed it off with a soft stream of water - cleaned the engine case and such. I idled and ran fine. It even revved fine. It was only when I revved it a bit wider that it all of a sudden jumped in RPMs. What is weird is that it ran with no spark. That should have killed it. I have been thinking, and maybe it was running so hot that it was combusting fuel without needing spark - similar to dieseling I suppose. I am probably wrong though. I am at a serious loss here. The motor is definitely fine though because I kicked it over once more to make sure it ran and it was fine.