A couple of you told me that my bike was running too lean (causing it to spit/backfire out of the carb) and suggested that I adjust the air/fuel mixture to richen it up a little bit. I have a Mikuni carb on this thing and a local old timer told me that I need to adjust the accelerator pump to achieve the same thing. According to to the Mikuni manual, it could be either one.

I really don't want to mess the settings up on this carb by playing around with something I really don't know how to mess with. With all that being said, which adjustment would you guys mess with first? Thanks!

 

Opening throttle slowly and it pops would be mixture,opening quickly would be accelerator pump.You are getting in a grey area that needs someone who has some knowledge of carbs observing what happens.

 

I agree with Tom. Carbs are one of the things about bikes that require a degree of skill to diagnose and put right. We can either spend a long time trying to learn, or get it done properly while enjoying a coffee.

 

Nah, its way easier than that. Adjust the mixture to get the highest. smoothest idle you can, re adjust idle speed.

If it still spits then adjust the accelerator pump (but memorise how many turns you alter it by in case you need to set it back).

If you get to 4 turns out on the idle screw and its no better you might need a bigger idle jet.