First off I should say I am very new to NSR's and bikes for that matter. I recently bought a MC21 and have a problem with it and thought that this would be the best place to start.

When I have the choke on it runs fine, but when I turn the choke off it is very difficult and rough running. If the choke is off and I try and start riding in first gear it really wants to stop running. I really need to give it about 7,000 rpm's to get a semi smooth start. Also when rolling and any gear with the rpm's at about 5,000 or lower it studers/chokes and dramatically loses power. If I switch the choke back on it works fine again.

I am only slightly mechanically inclined but a friend of mine has a shop here in Fukuoka, and he isn't sure what the problem is either. He admits he doesn't have a lot of experience with NSR's though. Any help or advice would greatly be appreciated.