Boxerworks.com

I have a R75/5 that i swapped from series 9&10 to 13&14 Bing 32mm carbs. Should I run the jetting listed in the Bing book for the later series of carb? The 9&10 call for a 135 main, 2.70 needle jet and a 45 idle jet, whereas the 13&14 say 145 main, 2.66 needle jet, and 50 idle jet. I was wondering if they made changes to the later carbs that made it run richer jets? The bike seems to run alright, but its my first airhead and first vintage bike, so I have no idea how it compares to others.

Welcome! If it were me, I'd run the settings/specs based upon the carb number. Unless I'm reading it wrong, going to a smaller needle jet will make the bike run leaner...of course there is a needle that goes along with that, too. A main jet doesn't really make significant differences until you get deeper into the throttle. Guess it depends on how your ride. IMO, run the specs per the manual.

Kurt

LargeStache wrote: ↑Wed May 01, 2024 6:45 pm The bike seems to run alright, but its my first airhead and first vintage bike, so I have no idea how it compares to others.

Airheads shouldn't run just 'alright'. They should run 'amazingly well''.
My suggestion is to track down a reputable airhead guru in your area and ask him to road test your bike to get an expert opinion on the overall performance of your bike.

gspd, That's a good idea, one which I've thought about. I need to put some more shake down miles on it before I try to track down a guru.