Carb Screws

[redliner1973]

I have a question about the carb screws that are on the top of my carbs right where the intake boot starts. they are very small, not covered, but I am wondering do they control idle mixture or overall mixture, and which way to adjust them (bike is running slightly lean, got back from a 400 mile trip on interstate, at 80F, and plugs where white/very dry and no deposits, also engine pinged alittle when going up hills at 2/3 to 3/4 throttle.) The boots where replaced last year, and carbs where sync'd a month ago. Air filter was serviced this year also, as was a new petcock installed and I usually run 89 octane in the bike. :twisted:

[daveo]

they're the idle fuel mixtures,they really only affect idle and a little off idle, they adjust the airflow, so out is leaner, in is richer. If it ran fine(no pinging) on 89 before, and you've got a new petcock,air boots, make sure your fuel line isn't pinched, tank is venting, etc., check the timing for too far advanced

[redliner1973]

Well, I cannot do much about the timing, as it is electronically controlled, but I have checked venting, lines, etc, I just thought that the way the plugs looked, that it was too lean. the pinging only happens when the bike is warm, I.E. an hour of 60-70 mph riding, and only at 2/3 to 3/4 throttle. I went to a b9es plug, but didn't really notice a change in things, so gonna go back to the b8es's. I was just hoping for an easy fix to this. :twisted:

[daveo]

With these electronic ignitions the timing is still adjustable, by rotating the plate the Hall Effect triggers are mounted on,(under right side crank end cover) you can also try higher octane and/or the colder plugs, pinging=no-good

[redliner1973]

I will see what I can do with the plate, but I have already done the higher octane and colder plugs (the b9es NGK's). Didn't help it. It was doing this same thing last summer, I though maybe it was just too hot outside, but should be doing it, my other bike never did, and it worked harder than Suzi does. :twisted:

[Anonymous]

maybe a small washer under your mid range needles would help your plug color

[daveo]

just rotate the trigger plate a 'tad' in the direction the engine crank turns

[Anonymous]

they're the idle fuel mixtures,they really only affect idle and a little off idle, they adjust the airflow, so out is leaner, in is richer. If it ran fine(no pinging) on 89 before, and you've got a new petcock,air boots, make sure your fuel line isn't pinched, tank is venting, etc., check the timing for too far advanced

If they're on the engine side of the carb, they're fuel meter screws. In which case, the opposite is true. Turning them in leans the mixture, turning them out richens it.