Most Norvins have a problem with clearance of the front carb. with the bottom of the tank usually requiring a cutaway or an extended serpentine manifold to move the carb. down or out. I have a rather elegant solution which seems to work quite well. I have a 3/8 I.D. fuel hose which is clamped onto brass connectors fixed into the tank at either end. This line runs into the tank from the front and exits directly above the carburettor. The throttle cable slides neatly through this tube which allows an easy run throttle to slide without any kinking. I have a fibreglass tank which made drilling holes and fixing the connectors quite easy but the same principle could be used to modify a metal tank. The downside is that some dexterity is required when removing the tank as the carb slide has to come out at the same time. I have Mk 1 Concentrics which are fairly tall in fact on my bike the top half centimetre of the carburettor is actually in a recess in the bottom of the tank.
Regards
edward
Regards
edward