Re-Re jetting Carbs. Input needed

[BNR34RB26DETT]

well im looking to re-rejet my cb.
Timing is right and points are good. carbs are synced but my bike has hard time idling without giving gas and it shuts off as soon as i give it more than 25% gas.
I dont think i have enough fuel going into the bike.

My current setup is

75 CB550
Velocity stacks
4 to 1 exhaust

I am running

40 slow jets
115 main jets

At ocean level.

What is everyone else running on setup similar to mine? should i go with something even larger? Maybe 120/ 42?
Stock jets on cb550 are 100 for main and 38 for slow

any comments would be appreciated

Thanks!

 

[BNR34RB26DETT]

bump

 

[focusinprogress]

slow jet sounds fine. how many turns out is your mixture screw? what is your idle set at? is this problem occurring both with choke on AND choke off? what do the plugs look like if you put fresh ones in and try to keep the rpms low for a few mins to see what color the tips of the plugs get? have you moved the e-clip position on the needles at all?

when I had stacks and 4-2 on my '75 cb550, I was at #40 pilots, 2 turns out, needle clip second from the bottom, and 120 mains....but that means nothing to another bike, gotta read the plugs!

 

[Sonreir]

Sounds like too much fuel, to me. That a huge jump in jetting without much in the way of mods. Put it back at stock and see how it runs.

 

[Sonreir]

You already have an open thread for this issue. Locking this one.