Motorcycle Repair: CB 750 4 K Jetting, pod filters, cb 750

Question
I went through this 30 years ago and forgot. I have 78 CB 750 , am adding Mac 4-1 Header and K&N Pod filters P/N RC-2314, Trying to determine jet changes for this setup. Bike will be used mostly for cruising, occasional blvd blast.
Thanks for any help, really enjoy this site. Ride Safe
George Haile
Houston

Answer
George, the little Honda tune-up book I have says you have 110 main jets in there now. Generally, you go up on the main jet sizes about a step per change.. i.e. one step for an exhaust change and one for an air filter change = 120 mains. That will get you in the ballpark, anyway. If you have access to a dyno shop, that will speed up the process. Depending on how it behaves, you may have to change the needle positions to overcome a flat spot off-idle or mid-range, which isn't particularly easy. If that doesn't work on the off-idle transition, then you may have to go up from #35 to #38 idle jets.

Bill Silver