Big Problem with my MINI

[Sjorge450R]

I have a race predator 90 with the Hetricks power up kit. The thing is, when I ride it at my house the quad rocks, but when I went to my race this weekend it had NO power. I believe we currently have the stock jet size in right now. Does anyone know whats wrong...please help me out quick because I have another race this weekend. and we currently use a #8 spark plug (because of the head) I posted this in the mini section as well, but i will probaly get more responses here.
Thanks
Steve

[NacsMXer]

There wasn't a big change in elevation between your home and the track was there? If so, that can mess with your jetting along with various temperature and humidity variances. That's about the only thing I can think of right now based on your symptoms :ermm:

[Sjorge450R]

do you know if when you go up in altitude you go down in jet size. Im clueless about jetting.

[NacsMXer]

Higher altitude means the air becomes less dense, causing a richer than normal condition. So you're right, to compensate you would jet lower to lean it out a bit. Still don't know if that's the cause of your problems though :ermm:

[Sjorge450R]

what else could it be

it works 100% here at my house just not at the two tracks... it has to be the jetting

[QuadJunkies]

Originally posted by Sjorge300EX
what else could it be

it works 100% here at my house just not at the two tracks... it has to be the jetting I cant think of anything else but Jetting, also, is it tapped out at these tracks compared to when your home?? Maybe a gearing change may also help, but sounds like it may just be jetting to Start with.

[400exstud]

If it was really hot the day of the race it may run like chit because hot air is also less dense. Air temp affects jetting, as does elevation, and countless others.