2004 cr85 bottom end issues

[bishbabe]

Hi - we took my sons cr85 to the local practice track on the weekend . he came off complaining about the lack of bottom end " .i tried it and it seems flat as f__k .

we have had the bike for a few weeks now , bike starts ok and everthing else seems ok . i havnt done a top end yet , but before i do i would like some advise as to what to look for to try and rectify the lack of power .

[jump6pack]

These small cc 2 strokes don't have much bottom end to start with. They are made to be screaming and you can't ride them like a trail bike. It took my son a while to get used to this when he switched from a TTR125 to a CR85. He would try to ride it like the TTR, easing off to start and then short shifting. Now he takes off at higher RPMs and tries to keep it in the powerband. If you have seen a drop in performance since you have had it, first thing I would check is the plug. They are prone to fouling if you don't keep the exhaust gas temp way up. Good luck and let us know what you find.

Jim

[bishbabe]

thanks for your reply - i took the bik apart last night , i have to strip the carb right through now . the piston looks knackered and the head looks like it needs decoking ,do you know the best way to de coke the head , and would you look at replacing the stock ree valve with an aftermart part ?

thanks again .