Carb was used

 

If you don't have the #50 AP nozzle it appears maybe you didn't get everything included in the later version kit. What side of the carb are the throttle cables on? Were you able to use the stock cables? The Early HSR 42 kits had the cable hook up on the left side of the carb and required new throttle cables. The slide didn't ride on bearings and the kit didn't include the #50 AP nozzle either.

http://www.tecdist.com/mikuni/Click%...ni%20Carbs.htm

Tech23