I went to Glamis last week and rode for a week. I took my alcohol bike and was having a great time smoking anything that I could find during the week. Not many people there during the week. On Wednesday I was at Oldsmobile hill and my son told me the Atv was idling real fast for some reason and had lost some power. He got off and I started it and listened to it and it was idling too fast. I pulled the seat off and started to look at things when all **** broke loose. The motor started to run away as if someone was holding the throttle wide open. I shut the kill switch off and nothing. I turned the ignition off nothing. I pulled the spark wire off nothing. We filled the air box with sand to choke off the air NOTHING. I shut off the fuel and turned the purge gas on. This thing ran 10,000+++++ rpm for at least three minutes before it finally it ran out of fuel and shut down. It broke two girdle stud bolts out of the base from the head. It was dieseling from the high compression and was sucking air in through the base gasket which made it lean. After it finally shut down it blew the red lid off the radiator overflow box. All said and done the engine still had good compression the next day I cleaned out the air box and put the plug wire back on and it started right up. Amazing. I don't know if I am going to put it back on alcohol because it scared me to think what might have happened if someone was riding it when this happened.

 

WOW!! Thats odd. Thats even more odd that it still ran and had compression after all of that. I guess it is a testiment to HPD's and Bubba's workmanship[img]i/expressions/face-icon-small-smile.gif[/img]

 

Wow ,that could have been real bad.I often think about that myself.So what do you think happened.Do you think the base nuts came loose ?

 

If that should ever happen again try pulling the choke - usually flooding it will get it under control. Were you jetted OK? I think you were probably on the lean side and then started dieseling (that's why the kill switch didn't do squat).

 

Look for a crack in the jug or the case.I have heard of some cracking and the engine run away from a lean condition,I hope this is not your case. Good Luck

 

Yes it is a testimate to Bubba's work. I do not believe that it was running lean before I had my problem. I think it blew the base gasket and was sucking air in at the base and this caused it to run lean then everything snowballed from there. I was looking at the base bolts when they broke. They did not come loose they snapped at the base. That was when I thought it was going to spread scrap metal everywhere but it didn't. I think however the rod is an inch or two longer than it used to be. The motor was screaming for over three minutes.

 

Sorry to hear this happened Pennyless but I'm glad this didn"t happen with you or your son on it. If you don't mind me asking how many hours do you have on it ?

 

how did it run w/o spark... did it get so hot that the heat ignited it?

 

I have heard this happening with diesels. base gasket goes and it gets air and fuel (oil) from the bottom, it isn't pretty.

The faster the motor runs, the more oil it'sucks, the more it sucks, the faster it's runs. Doesn't stop until something gives or runs out of oil. (fuel)

 

This is the second base gasket that I have blown. The first time I had probably ten tanks of fuel through it. So that would be about 10 hours. This time I only had a few hours on it. The first time is when I bought it so I can't tell you how much time it had before I got it. Yes I did recheck the bolt torque after the first couple of runs. It was ok.