Author Topic: anyone have a suggested jet size to go to for straigt pipes?  (Read 1079 times)

0 Members and 1 Guest are viewing this topic.

Offline cormier1989

  • Enthusiast
  • **
  • Posts: 132
  • [URL=http://img41.imageshack.us/i/69316472.png/][I
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

Offline kslrr

  • There is always a Blaster when there is a
  • Master
  • *****
  • Posts: 1,542
  • Raising her up right!
Re: anyone have a suggested jet size to go to for straigt pipes?
« Reply #1 on: July 06, 2009, 09:01:48 AM »
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.
Now  1972 CB350FX (experimental v2.0)
        1981 CB650c Custom with '79 engine (wifes)
        1981 CB650 engine
        2004 HD XL883C Custom
        1977 Yamaha XS750D (in progress)
Then 1972 CL175
        1964 Yamaha YGS-1T
No ride is a Bad ride

Offline scunny

  • Old Timer
  • ******
  • Posts: 4,618
  • don't call me expert
Re: anyone have a suggested jet size to go to for straigt pipes?
« Reply #2 on: July 06, 2009, 11:34:20 AM »
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
past-cb100,ts250,cb500,cb500,gs1000,gs650g.phillips traveller
present-CB 650 retro
            VTR1000F3
           XL250S riverbed rocket
           TS250[sold]
           TS185[sold]
           XL125S[sold]
           MT50 (white)
           MT50 (red)[sold]
           KN250/XS400 project
           XR/XL250 bitsa under construction
           SL100[sold]
           XL250R
           pedal(pub bike) leaks oil
my gallery http://gallery.sohc4.net/members/personal/scunny

Offline cormier1989

  • Enthusiast
  • **
  • Posts: 132
  • [URL=http://img41.imageshack.us/i/69316472.png/][I
Re: anyone have a suggested jet size to go to for straigt pipes?
« Reply #3 on: July 06, 2009, 11:47:46 AM »
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?

Offline scunny

  • Old Timer
  • ******
  • Posts: 4,618
  • don't call me expert
Re: anyone have a suggested jet size to go to for straigt pipes?
« Reply #4 on: July 06, 2009, 11:52:27 AM »
start from the stock settings and see how it runs then go from there.
past-cb100,ts250,cb500,cb500,gs1000,gs650g.phillips traveller
present-CB 650 retro
            VTR1000F3
           XL250S riverbed rocket
           TS250[sold]
           TS185[sold]
           XL125S[sold]
           MT50 (white)
           MT50 (red)[sold]
           KN250/XS400 project
           XR/XL250 bitsa under construction
           SL100[sold]
           XL250R
           pedal(pub bike) leaks oil
my gallery http://gallery.sohc4.net/members/personal/scunny

Offline kslrr

  • There is always a Blaster when there is a
  • Master
  • *****
  • Posts: 1,542
  • Raising her up right!
Re: anyone have a suggested jet size to go to for straigt pipes?
« Reply #5 on: July 06, 2009, 03:21:51 PM »
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.
Now  1972 CB350FX (experimental v2.0)
        1981 CB650c Custom with '79 engine (wifes)
        1981 CB650 engine
        2004 HD XL883C Custom
        1977 Yamaha XS750D (in progress)
Then 1972 CL175
        1964 Yamaha YGS-1T
No ride is a Bad ride