1982 CR 480 carby settings

[rtb]

Mate has just bought a CR 480 1982 and it has a Keihen carby, asking is this carby worth keeping or should he change it to a 38 mm Mikuni and if so can you suggest any jetting specs?

Any help would be appreciated as the bike is not running well up top.

Thanks

Bruiser
PS What spark plug whould he run in the bike

[caps 999]

i run the stock kehin on mine does the job fine i run std jettin is 185 main and i think its a 72 pilot i actually run a br7es plug in mine as its a lil hotter bit better for newer fuels