I found my old book on carb jetting info ,these are the jets i used in my Weber's on a cb750 sohc 750 ,then a 960 version ,these work well i have proven them to be good
RC ENGINEERING WEBER 40 SIDE DRAUGHT CAR BS CB750
idle jets 45f9
air correctors 150
main jets 120 (145 960cc)
emulsion tubes f16
venturies 32mm
More photos, more info!
ReplyDeleteThis is a very cool setup, I don't see many carburetor swaps on the old Hondas. I wish I had a better carburetor setup for my 78 550. The stock rack has only been a pain since the beginning.
Brady
Behind Bars - Motorcycles and Life
http://www.behindbarsmotorcycle.com/
What (exactly) kind of webers??? 40 dcoe what? Tx Bri
ReplyDeleteForget about running anything on the 1977-78 cB550 or 750's except the stock air box.!
ReplyDeleteI worked on a CB750 for months to get the carbs to work with stacks or pods. Forget it.!!
The stock air box limits the intake area to 39% of the total area of the actual carb openings.
The air box is like a giant choke.
i have worked on cb s for 30 yrs and ran webers and amals and smoothbores on them,also SU carbs ,i also ran a 1000cc Russ Collins sb750 drag motor on th street,a cb750 /960cc supercharged honda 750 ,so i think i know what i am talking about ,its all a matter of jetting and engineering and i have ran all of these bikes with no problems,cb750s with standard carbs and no airbox will work fine with a 10% increase on the main jets as do cb550 s ,im on my 16th cb750 at the moment
ReplyDelete30mm chokes? Ive got this on a stock cb750a, and its not close:
ReplyDelete32mm chokes
4.5 Aux Venturi
F16 Emulsion Tube
125 main
45F8 Idle jet
60F5 starter jet
35 pump jet
Pump Spill 55 (what is stamped)
.200 needle valve
150 AIR CORRECTOR JET
Hi I have 110 main and 30 chokes and 45F8 idle on my 915cc runs very well but the tick over only lasts for 8 seconds on my dcoe twin 40’s
DeleteThat's my old motor.
ReplyDelete