Topic: CB550F build - need help jetting CR29 carbs

[akabek]

Hi Folks, hello to everyone as this is my first post on this forum. 

I purchased a 1975 CB550F last fall that has been converted to a cafe.  I just need to tweak a few things but my last challenge is jetting the carbs.  The is some insight into my current setup.

Stock engine
Dyna electronic ignition, 5 ohm coils and wires
Keihin CR 29 carbs
4-2 Jardin exhaust
D7EA spark plugs
Steel dragon velocity stacks with aluminum screens

Can someone provide me with base line jetting for this setup?  No matter what I do I get good low and high throttle response but the mid range is lagging and when I pull the plugs it seems to running rich.  Maybe the CR29 that came with the bike is too much carb for a stock engine.  This bike is for street riding.

I appreciate any help.

[akabek]

I emailed Keihin/Sudco asking for their baseline and this was their response:

120 mains, 70 pilots, YY5 in the 4 position, 2.5 slide, and 170main air jet.

I have no idea what the 2.5 slide means.

This is what I am currently running and the plugs are black when I pull them  100 mains, 48 pilots, YY8 in the top clip position - lean, and 240 main air jets.  Maybe I am not using the correct process to check the plugs.

The jets  and needles suggested by Sudco seem rich.

I also asked the base line for the same bike setup but a 4-1 exhaust....apparently they suggest the same base line.  I find that hard to believe.

[akabek]

I did not get any responses to this thread but I thought I would provide an update.  I ended up with 65 slow, 120 mains, 5th position on the needle and 1.5 turn on the mixture screw and the bike now has steady acceleration throughout each gear.  I do need to do some plug chops to see how the plugs are at idle, 1/4, 1/2, 3/4 and open position.