Motorcycle Repair: 2006 honda crf70, honda crf70, bike cranks

Question
This bike cranks easy and idles great. The problem is when you rev the engine, it sputters and misses. I've check the spark plug and choke. Any ideas on what the problem could be?

Answer
Although I don't have much to go on, but in general - if it's a hesitation or misfire in the 1/4 to 3/4 throttle range, you are too lean on your needle jet.

Raise the needle jet (lower the clip) one position and retry.  If you are unfamiliar with jetting - purchase a service manual from your dealer.  This is an easy one to do though, just unscrew the top of the carb, pull out the slide and you'll see the needle on the end, this needs to be raised one, maybe two positions.

If this doesn't do it let me know.

Anthon
'Ride Today - Live Again'