Author Topic: How I made carb vacuum adapters  (Read 4852 times)

0 Members and 1 Guest are viewing this topic.

Offline Cannibal

  • Full Member
  • *
  • Posts: 44
How I made carb vacuum adapters
« on: July 27, 2008, 02:24:15 PM »
I found some 3/16-3/16 double barbed fittings at Home Depot because California Sport Touring has been out of adapters for like 2 months (that reminds me, I need to call for a refund), and NEEDED and alternative. Here's how I modified 4 of these to make vacuum fittings to sync my carbs.

First, I wrapped one end with a couple wraps electrical tape so they didn't get all scared up from the drill chuck. I chucked that end up and spun it and using a hack saw, cut all but the last 2 barbs off (actually, only 1 barb left, plus the one against the shoulder in the center, so 2 "sections" were left).

I spun it up again in the drill and took a hand file and filed it until it was 5mm. After that, I took my 5x.8 die and threaded it. Then touched up the end threads with the file (45* angle) and spin again to give a light taper. I took a 5/16 drill bit and de-burred the cut end, then ran a pipe cleaner through to clean out the debris.

Unchucked it, removed the tape and threw an o-ring on, then installed them. They worked like a charm. Of course, my carb sync has 3/16" tubing on it, so they fit great.

Package:


Chuck it up:


Sorry, no pic of it cut off, but cut all but 2 "sections" of it off before filing it to 5mm (less material to file, and one of the barbs gives a nice place to rest the hack saw blade).

File it:


Thread it:


Clean it, o-ring it:


Install it:


Sorry for the crappy pics, a photographer I am not. But you get the idea.

Steve

« Last Edit: July 27, 2008, 02:27:51 PM by Cannibal »

Offline bwaller

  • Really Old Timer ...
  • *******
  • Posts: 7,484
Re: How I made carb vacuum adapters
« Reply #1 on: July 27, 2008, 05:00:32 PM »
It's a bit of a stretch to those inside carbs, but good job Steve.

Offline rbmgf7

  • 2>4
  • Expert
  • ****
  • Posts: 881
Re: How I made carb vacuum adapters
« Reply #2 on: July 27, 2008, 05:05:34 PM »
as a guiness commerical would say "brilliant!"

lol, cordless drill a.k.a. the mini portable lathe. i've used my drill for similar situations  :D

Offline mystic_1

  • Really Old Timer ...
  • *******
  • Posts: 6,071
  • 1970 CB750K
Re: How I made carb vacuum adapters
« Reply #3 on: July 27, 2008, 06:25:30 PM »
Nicely done.

mystic_1
"A ship in harbor is safe, but that is not what ships are built for."
- John Augustus Shedd

My build thread:  http://forums.sohc4.net/index.php?topic=68952.0

Offline Cannibal

  • Full Member
  • *
  • Posts: 44
Re: How I made carb vacuum adapters
« Reply #4 on: July 27, 2008, 09:26:16 PM »
Thanks guys. I know others one here have asked how to make some, so I thought I'd post this up.

The inner ones aren't that bad. The tubing I'm using is the clear stuff, but not the fish tank stuff, that's way thin. This has a pretty heavy wall and I'm able to just push it right on the inner ones. They are a bit tough to thread in, but I wrapped some Teflon tape around them to seal and installed them permanently. Since they really aren't seen, I figured no body would even notice, unless they were looking for them. They have a black vacuum cap on them, so they are sort of "camouflage".

Steve

Offline jason teamshralp

  • Enthusiast
  • **
  • Posts: 204
Re: How I made carb vacuum adapters
« Reply #5 on: July 27, 2008, 09:59:28 PM »
as a guiness commerical would say "brilliant!"

I thought the exact same thing when I saw this.

Offline chrislib

  • Hot Shot
  • ***
  • Posts: 345
Re: How I made carb vacuum adapters
« Reply #6 on: July 28, 2008, 08:29:53 AM »
Nice fab work! Here`s a trick for getting the adaptors on the inside carbs, I take a t-15 torx driver and fit it into the end of the adapter, depending on the inside dia of your particular adapters you may need a different sized torx (t10 or t20 perhaps). Oh, my synch tool is a motion-pro.

Chris...closet Idlefiddler
#1975
1973 CB750K...CANDY BACCHUS OLIVE

Offline JimHanus

  • Full Member
  • *
  • Posts: 4
    • Michigan Imaging Supply
Re: How I made carb vacuum adapters
« Reply #7 on: May 24, 2013, 12:47:44 PM »
Nice idea, but how do you keep from dropping the cut off piece under the workbench? Should have bought 2.  :'(

Offline flybox1

  • My wife thinks I'm a
  • Really Old Timer ...
  • *******
  • Posts: 14,301
Re: How I made carb vacuum adapters
« Reply #8 on: May 24, 2013, 12:56:53 PM »
nice work steve, with felt washers and rubber caps, you can leave them in  ;)
'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 mineā€¦"

Offline 70CB750

  • Labor omnia vincit improbus.
  • Really Old Timer ...
  • *******
  • Posts: 14,786
  • Northern Virginia
Re: How I made carb vacuum adapters
« Reply #9 on: May 24, 2013, 01:00:57 PM »
Ingenious!

Offline Vinhead1957

  • Expert
  • ****
  • Posts: 1,196
Re: How I made carb vacuum adapters
« Reply #10 on: May 24, 2013, 04:50:24 PM »
Great idea! Thanks for sharing

Offline BobbyR

  • Really Old Timer ...
  • *******
  • Posts: 12,367
  • Proud Owner of the Babe Thread & Dirty Old Man
Re: How I made carb vacuum adapters
« Reply #11 on: May 24, 2013, 07:31:45 PM »
Very clever
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 ncstatecamp

  • Expert
  • ****
  • Posts: 799
Re: How I made carb vacuum adapters
« Reply #12 on: June 07, 2013, 05:04:29 PM »
just a heads up, you can get adapter from amazon for pretty cheap (free shipping if you have prime) http://www.amazon.com/Motion-Pro-08-0013-Carburetor-Adapter/dp/B000OO4PVM