I send my cylinder and head to Eric Gorr,and jet by teem green spec.,or just
put 13 tooth on front and drop 1 tooth in the rear from stock.My run fmf pipe
and power coreII silencer which make power come on earlier than stock so make it less pippy.My son love it.,but still not significantly improve for the money that I have to spend. I think you youngster need to ride more aggressively (it made for intermediat to expert rider likely)
At the track a few weeks ago, one of the kids there had a 00' KX 65 with a Pro Circuit platinum pipe and his Dad let my 12 yr old (John) ride it to compare to my 8 yr old's stock 01 KX 65. John said it was smoother on the bottom and revved longer, whereas the stock would hit hard in the middle and top out quickly.
I will be looking at this pipe when I'm able to afford it.
We had the same problem and sent the cylinder to Eric Goor and put on a FMF Fatty pipe. Not only did it smooth out the hit, the bike has more bottom and top end than before. I highly recommend the porting and if you really want to get the most out of the KX65 motor send it to 2-Fast-Racing and get the hot rod kit. This makes it way faster than the KTMs.
send cylinder to Gorr for beginner porting. Fraction of pipe $. Lots more bottom. Does not over rev. Quick turn around time. But son still gets holeshots and good starts. Lower gearing. 13/45 or 14/48-49.:) Quick & easy also think about restrictor in exhaust. Richen up main (250-260 on good pump gas) maybe richen needle. Retard ignition slightly.(less hit, more over-rev) firstname.lastname@example.org. #11 Dist 17 stadium