Topic: anyone have a suggested jet size to go to for straigt pipes?

[cormier1989]

i did another post before but it diddnt seem to work. I wanted to ask while my carbs are off of my bike if anyone knew a good size jet to go to for straight pipes on my 1980 cb650? Im not looking to have a racinf bike, i just want straight pipes

[kslrr]

There is no exact answer.  It takes trial and error to get it right.  With that said, On my '79 CB650 engine with stock pipes and pod filters, I went from from 35 idle/ 90 main/1.5 turns on the idle screw to 47/110/1 turn.

[scunny]

to add on the in exactness.........79 650, slightly baffled 4into1 and pods, 37idle 110main and 2 turns on the idle circuit, runs like a dream

[cormier1989]

so how many times did it take before you figured out what worked and what didnt? I would be running 4 to 4 pipes. I guess what im kind of asking is, what would you do in my situation?

[scunny]

start from the stock settings and see how it runs then go from there.

[kslrr]

I tried 2 combinations of jets, and 2 combinations of Slides and Jet Neadles.
So, 2 squared=4 combinations.  I had 2 different models of carbs that I was able to mix/match to get what I wanted.  She starts up nice, but takes about 15-20 minutes running on half choke to warm up.  Once she does, she pulls good.

Some additional information:  The CB650 (all years) runs lean to begin with.