« previous next »
Pages: [1]   Go Down

Author Topic: Where the hell are my idle and mixture screws on my 78 cb750 carbs?  (Read 1692 times)

0 Members and 1 Guest are viewing this topic.

Offline specialone70

  • Full Member
  • *
  • Posts: 38
Where the hell are my idle and mixture screws on my 78 cb750 carbs?
« on: September 23, 2015, 06:30:44 PM »
I can't find them on my bike. I looked at pictures online and it seems previous years have really obvious screws but for some reason pictures of '78 carbs don't have the screws in the same spot. Sorry if I'm being stupid but I'm really confused. Thanks!
Logged

Offline Mantree

  • Hot Shot
  • ***
  • Posts: 596
Re: Where the hell are my idle and mixture screws on my 78 cb750 carbs?
« Reply #1 on: September 23, 2015, 07:30:19 PM »
Can you give us photos so we know what we are working wih

Sent from my SM-G900V using Tapatalk

Logged

Offline specialone70

  • Full Member
  • *
  • Posts: 38
Re: Where the hell are my idle and mixture screws on my 78 cb750 carbs?
« Reply #2 on: September 23, 2015, 08:24:31 PM »
Here's an image I found of the same carbs: http://img.photobucket.com/albums/v702/trailsforus/IMG_0857-1.jpg

Here's a picture of what the older ones (and the ones in my manual) look like. You can clearly see the idle and mix screws: http://honda-cb750-s.456789.n3.nabble.com/file/n4022423/1969-70-carbs.jpg
Logged

Offline seanbarney41

  • not really that much younger than an
  • Really Old Timer ...
  • *******
  • Posts: 10,835
Re: Where the hell are my idle and mixture screws on my 78 cb750 carbs?
« Reply #3 on: September 23, 2015, 09:08:17 PM »
not much of use in that goofy pic...who is the dumbass that looped their float bowl drain hoses up to the adjacent carb?

Idle mixture is not visible in the pic, it is in front of the float bowl pointing up.  Idle speed screw is not visible either.  IIrc, it is on the the rack between carb 3 and 4...kinda hard to get at...
Logged
If it works good, it looks good...

Offline Mantree

  • Hot Shot
  • ***
  • Posts: 596
Re: Where the hell are my idle and mixture screws on my 78 cb750 carbs?
« Reply #4 on: September 23, 2015, 09:54:45 PM »
Quote from: seanbarney41 on September 23, 2015, 09:08:17 PM
not much of use in that goofy pic...who is the dumbass that looped their float bowl drain hoses up to the adjacent carb?

Idle mixture is not visible in the pic, it is in front of the float bowl pointing up.  Idle speed screw is not visible either.  IIrc, it is on the the rack between carb 3 and 4...kinda hard to get at...
Beat me to it they are post 76 carbs as for the idle mix screw when you tear them down grind off the little tab, all it dose is liners how far you can turn the screw with the float bowl on

Sent from my ME302KL using Tapatalk

Logged

Offline flybox1

  • My wife thinks I'm a
  • Really Old Timer ...
  • *******
  • Posts: 14,301
Re: Where the hell are my idle and mixture screws on my 78 cb750 carbs?
« Reply #5 on: September 24, 2015, 06:50:54 AM »
bottom left of this picture
(the RED arrow is pointing to the pilot jet)
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 BobbyR

  • Really Old Timer ...
  • *******
  • Posts: 12,367
  • Proud Owner of the Babe Thread & Dirty Old Man
Re: Where the hell are my idle and mixture screws on my 78 cb750 carbs?
« Reply #6 on: September 24, 2015, 12:40:47 PM »
They are recessed back toward the head at the rear of the floatbowl. You can see the screw in the pic above.
Feel around with a cold engine. Be ready to burn your fingers when making the adjustment on a running motor. They are mixture screws not air screws found on early models.
Logged
Dedicated to Sgt. Howard Bruckner 1950 - 1969. KIA LONG KHANH.

But we were boys, and boys will be boys, and so they will. To us, everything was dangerous, but what of that? Had we not been made to live forever?

Offline specialone70

  • Full Member
  • *
  • Posts: 38
Re: Where the hell are my idle and mixture screws on my 78 cb750 carbs?
« Reply #7 on: September 24, 2015, 10:23:49 PM »
Ok got it. Thanks a bunch, guys. This forum never lets me down!
Logged
Pages: [1]   Go Up
« previous next »