« previous next »
Pages: [1]   Go Down

Author Topic: What's this screw on 79 cb650 carbs  (Read 1759 times)

0 Members and 1 Guest are viewing this topic.

Offline BollarNPS

  • Enthusiast
  • **
  • Posts: 154
What's this screw on 79 cb650 carbs
« on: October 30, 2015, 07:52:59 AM »


Is this the screw to adjust when syncing carbs?
Logged

Offline gloken

  • Full Member
  • *
  • Posts: 65
Re: What's this screw on 79 cb650 carbs
« Reply #1 on: October 30, 2015, 07:55:16 AM »
I'm sure someone will correct me if I'm wrong.

Those Keihin PD carbs have a port to attach a manometer when you sync the carbs.  There should be one on each carb.
Logged
'77 Honda CB550K
'84 Honda V45 Sabre 750

Offline RevDoc

  • Hot Shot
  • ***
  • Posts: 552
Re: What's this screw on 79 cb650 carbs
« Reply #2 on: October 30, 2015, 07:57:17 AM »
Quote from: gloken on October 30, 2015, 07:55:16 AM
I'm sure someone will correct me if I'm wrong.

Those Keihin PD carbs have a port to attach a manometer when you sync the carbs.  There should be one on each carb.

Gloken, you are not wrong! ;D
Logged
Dana

'78 CB550K--Angie
'82 CB750 Custom--Eva



As soon as you straddle a bike expect every other driver on the road to suddenly start competeing for the title "Dumbestsonofa#$%*inallNorthAmerica!!"

Offline BollarNPS

  • Enthusiast
  • **
  • Posts: 154
Re: What's this screw on 79 cb650 carbs
« Reply #3 on: October 30, 2015, 07:59:39 AM »
Great! Then next question is where are the adjusting screws.
Logged

Offline gloken

  • Full Member
  • *
  • Posts: 65
Re: What's this screw on 79 cb650 carbs
« Reply #4 on: October 30, 2015, 08:09:07 AM »
I thought this link had a good description of it:
http://www.motopsyco.com/2013/08/09/vintage-piston-valve-keihin-carburetor-overhaul/

When I did mine, I used a sheet called "How to remove, clean, rebuild, and reinstall keihin PD46a carbs"  by Brian Barnes, my bike's shop manual, and the manual that came with my manometer.

I think you'll want to understand how carbs work, and know your way around them, before you try to sync them. But that's just me.
Logged
'77 Honda CB550K
'84 Honda V45 Sabre 750

Offline BollarNPS

  • Enthusiast
  • **
  • Posts: 154
Re: What's this screw on 79 cb650 carbs
« Reply #5 on: October 30, 2015, 08:12:29 AM »
Thanks a bunch sir!
Logged

Offline flybox1

  • My wife thinks I'm a
  • Really Old Timer ...
  • *******
  • Posts: 14,289
Re: What's this screw on 79 cb650 carbs
« Reply #6 on: October 30, 2015, 08:12:56 AM »
Quote from: BollarNPS on October 30, 2015, 07:59:39 AM
Great! Then next question is where are the adjusting screws.
Either between 1/2 and 3/4 for screws with locknuts, or, under the top caps.
My 750K8's PD carbs have the adjuster screws under the caps.
My 350F carbs had them between the carb bodies. 
Logged
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mine…"

Offline JimJamerino

  • Yay! I'm a
  • Hot Shot
  • ***
  • Posts: 272
  • Not rich enough to be "eccentric."
    • My CB650C build thread
Re: What's this screw on 79 cb650 carbs
« Reply #7 on: October 30, 2015, 11:00:05 AM »
On the 650 they're under the top caps.
Logged
~ Jim

formerly "emperorspartacus"

There are old bikers.  There are dumb bikers.  There are no old, dumb bikers.

My CB650C rebuild http://forums.sohc4.net/index.php?topic=74212.0

Offline BollarNPS

  • Enthusiast
  • **
  • Posts: 154
Re: What's this screw on 79 cb650 carbs
« Reply #8 on: October 30, 2015, 11:55:02 AM »
meaning where the slides are? and may be a dumb question but its okay to run the bike with those tops off?
Logged

Offline JimJamerino

  • Yay! I'm a
  • Hot Shot
  • ***
  • Posts: 272
  • Not rich enough to be "eccentric."
    • My CB650C build thread
Re: What's this screw on 79 cb650 carbs
« Reply #9 on: October 30, 2015, 12:34:03 PM »
If you're looking straight down at the top of the carbs from a 79 or 80 CB650, there's 2 screws holding a lid on top of each carb. When you take that off, you can see the tops of the slides.

I wouldn't run without the top caps. You want the insides of your carbs to stay clean, and leaving the caps off will make that a tall order.
Logged
~ Jim

formerly "emperorspartacus"

There are old bikers.  There are dumb bikers.  There are no old, dumb bikers.

My CB650C rebuild http://forums.sohc4.net/index.php?topic=74212.0

Offline BollarNPS

  • Enthusiast
  • **
  • Posts: 154
Re: What's this screw on 79 cb650 carbs
« Reply #10 on: October 30, 2015, 12:56:48 PM »
Yeah I'm not talkin for long I'm just talkin about while vacuum syncing. Or do I run then shut off and make small changes and retry
Logged

Offline Airborne 82nd

  • Expert
  • ****
  • Posts: 828
Re: What's this screw on 79 cb650 carbs
« Reply #11 on: October 30, 2015, 01:03:39 PM »
Quote from: BollarNPS on October 30, 2015, 11:55:02 AM
meaning where the slides are? and may be a dumb question but its okay to run the bike with those tops off?

While syncing. Not riding :)
Logged
Pages: [1]   Go Up
« previous next »