i have recently had a new web cam installed and new valves.the motor has also been rebuilt . i have had the bike rejetted. the problem is that the bike wont open up it cuts out. can anyone help.

 

To me it sounds like your main jet is to big and is making it cut out on your top end. check your plug

 

Yeah, it does sound like a carb tuning issue, but to really help you more detail would be nice. How much throttle does it take before it breaks up? What size main is it? What's the plug look like? The main jet could be too small even, causing a lean condition (bad) and an uneven fuel burn in the cylinder.

-Marc