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
