I'm working on a friends 99 blaster. All original never had a piston or any thing done to it. last year he said the kids were riding it and turned it off and then it wouldn't start again. He tried a new plug and even a little either. So this week we pulled the top end. The piston looked great no wear marks the cyl looked good also.
Being a 99, I had it bored got a new piston and cleaned the carb. Put it back together and it started on the third kick and idled sweet. but now it won't rev much past an idle. give it some gas and it sounds like its cold, spits and sputters and back fires a little. I tried using the choke but it didn't help any. removed the carb again cleaned again put a new plug in and the same thing. starts on the first kick idles great but wont rev up. I then disconnected the kill switch and the key switch no change.
I don't think it's fuel related. sounds more like ignition or an inter mitten spark to me, like a rev limiter sounds like. I've rebuilt a few dirt bikes and atv's but this is the first blaster I've worked on.
so where do I go from here? what do the wires coming from the right side of the handle bars do, can it be jumped out if so where?
sorry for the long post but I wanted to list as much as possible.
Dave K.

 

Dis-Engage the Park Brake. [img]i/expressions/musicnote.gif[/img]

The switch in the Thumb Throttle is normally closed. To eliminate it from the system, unplug it and short accross the two wires going to the Brain. (just follow the wiring til there's a connector under the nose plastics.

The TORS box switch on the Carb is normally open To eliminate it from the system, just unplug it. This one unplugs above the drive sprocket under the edge of the seat.

The 99 may have something attached to the Park brake causing the rev limiting. My 2006 does, but I haven't bought a book on that one yet. My 89 has the above wiring and my book for it stops at 98. There's probably a different setup on the 99 and up models.

On the 06 there's a rev limiter switch on the Park Brake setp-up. I have a spare switch I got off ebay and tested it and can't remember wheteher it is normally open or normally closed. But if that switch is not pressed, it causes the symptoms you are having. It keeps something from accidently overrevving the motor while the ebrake is on, incase a kid or something happens. (cable freeze,...other possiblities) I think the manual will recommend start-up with Park Brake engaged, until warmed up. If it's engaged, it will cause the rev limitations you are experiencing. Dis-engage the Park brake if on and try again.[img]i/expressions/light.gif[/img]

 

Thanks Terrell
Did that and it runs great now.

thanks again

Dave K