Tech Help In Macomb Area Air Fuel adj screws

[DonB]

 I was wondering if soemone Locally (Macomb area) might be able to help me out with my litttle problem.  I sent Cori an email, but didn't realize that he's all the way out in the Saginaw area.

Late last year i installed some Cobra 6x6 pipes & decided to install the Cobra jet kit which is really just new needles.
After installing the needles I TRIED to adjust the Air fuel screw using that silly tool they provide, thats where my problem lies.
Looks like i have the fuel mixture a bit screwed up, & can't tell if i'm even turning the fuel mixture screw seems to keep slipping off. not to mention, it's a pretty tight area & almost totally blind operation.
 
The bike starts fine, but runs pretty rough & backfires,  before the rejet the bike ran perfect, no issues.
 
Anyway, I was hoping someone locally might be able to help straighten this out for me otherwise I'll have to try the local dealer.
 
Thanks for any help/suggestions!

Don Burgess
dburges5@yahoo.com
VRCC 3175

[Mr. Breeze]

Don,

I would like to suggest:

a.) Go back and make sure that all vacuum lines / caps are connected near the inside / bottom of the carb runner tubes. => Lean condition = backfire

b.) Also, you may have a concern with the sealing of the upper vacuum diaphragm on the carb that controls the idle mixture needles.

c.) In most cases, the bike should start, and idle fine even with the stock needles and the Cobra pipes installed.

d.) The noticeable concern would be a "flat spot" during acceleration when you go / transfer from the idle circuit to the cruise circuit of the carb.

e.) This flat spot or sag in performance is what the new needles and springs are there to address / correct. (Depending on the jet kit, moving the supplied e-clip up or down on the needle, changes how far into the jet the needle can travel thus either richens or leans out the mixture.)

f.) When it comes to adjusting the fuel mixtures, this procedure needs to be done using a "D" socket on the mixture jet screw, several (6 preferred) very sensitive vacuum gauges or the most actuate meter, a manometer (water column) to ensure actuate "balancing of the air / fuel mixture" of all six carbs.

g.) Once that is completed, each carb needs to have its idle speed set / matched to each other (synchronized to the #1 carb) to ensure a smooth idle and even performance (aka: balanced)

OR.............. re-install the original needles and springs and see how it runs then and try to re-adjust set the mixtures to what they were before