Details:
1975 Honda CB750F motor
657B carbs, Cleaned, rejetted w/ Velocity Stacks
#120 Main Jet
#40 Idle Jet
Idle Mix screw - 1 1/4 turns out.
4 into 2 Headers with shorty tips and glass packed, 8" baffles.
Stock coils and points
Float Height on all bowls (see pic)
The Problem:
First, it doesn't start with the choke on. I must remove the choke to start it. When cold and no choke, it fires the instant I touch the start button and revs nice under throttle. However, the idle has to be set high...because it wont idle below 1000 rpm. I will idle about 30 seconds...while it just starts to drop revs and finally die. Other than a bad idle, it runs great, pulls hard, and smells like the mixture is correct.
Possible "solution":
I found this "fix" for bikes with idle issues due to velocity stacks and/or open exhaust...interesting read.
http://www.hondachopper.com/garage/carb_info/idle_screw_mod/idle_screw_mod.html
1975 Honda CB750F motor
657B carbs, Cleaned, rejetted w/ Velocity Stacks
#120 Main Jet
#40 Idle Jet
Idle Mix screw - 1 1/4 turns out.
4 into 2 Headers with shorty tips and glass packed, 8" baffles.
Stock coils and points
Float Height on all bowls (see pic)
The Problem:
First, it doesn't start with the choke on. I must remove the choke to start it. When cold and no choke, it fires the instant I touch the start button and revs nice under throttle. However, the idle has to be set high...because it wont idle below 1000 rpm. I will idle about 30 seconds...while it just starts to drop revs and finally die. Other than a bad idle, it runs great, pulls hard, and smells like the mixture is correct.
Possible "solution":
I found this "fix" for bikes with idle issues due to velocity stacks and/or open exhaust...interesting read.
http://www.hondachopper.com/garage/carb_info/idle_screw_mod/idle_screw_mod.html
