It started running rough at idle (lumpy and missing), and if you free-rev and hold the gas anywhere in the rev range it seems to be missing a bit.. BUT it still seems to run fine while accelerating. It's just not as smooth as it should be (and it was smooth until we started messing with all the settings). What is the correct way to tune this carb (Mikuni sidedraft on 12a), and get the correct mixture and timing settings?



Thanks,

Matt

since you're tuning the mixture, leave the timing alone its just another thing to get wrong; ie you want to minimise the variables so you tune the right one to start with.



you wanna start with the idle. there is either a mixture screw or an air bleed screw or both. you wanna set the mixture at idle until you get the highest idle. i'm not sure but the mikini might have one screw for each barrel, these should be set the same. you can turn them all the way in gently and turn them out the same amount.



the rest of the tuning is done with jets and air bleeds, it might be a good idea to put an 02 sensor in with an afr guage, so you can tell if you're too rich or too lean, they can both feel the same



mike

Trust me, You dont want to mess with too many things at once. If its not helping or changing what you want to change, set it back the way it was before you go to the next thing. I did a little here and a little there and now I have big problems.

should I be adjusting the air bleed screw on the top side of my nikki....I havnt touched since I rebuilt it and my settings are really rough. the air adjust doesnt seem to do anything and the throttle,.....Well it only adjusts the throttle.

I need to adjust it to run richer I think.......I guess.

The Mikuni has one screw for each barrel. I don't remember what they were set at before unfortunatly, but I guess i'll have to start over by screwing them in completly and going from there.



Matt

yeah, keep em the same, other wise you can have it running too rich and too lean at the same time



mike