carb synch fittings

jvandyke · Posted: Thu Mar 11, 2010 9:18 am Post subject: carb synch fittings

I'm getting geared up to do a full tune on my '72 CB500. I have a nice set of 4 vacuum gauges (although they are Kawasaki issue...yuck). What do I need for fittings to hook up my vacuum lines on the intakes?

fasthonda · Posted: Thu Mar 11, 2010 6:34 pm Post subject: Fittings for vacuum guages

Most kits have brass adapters in box if lost you may be able to get screws metric that fit and drill out center and cut heads off then slip rubber over threaded portion after screwing into carbs start bike do not exceed 1000 revs or you will pull mercury into motor and lose it. on a 4 cyl honda cyl #2 is factory set and all other cycls are set to that cyl so if you havent changed carbs #2 is your reference point Good Luck Fast Honda

05c50 · Posted: Thu Mar 11, 2010 7:01 pm Post subject:

Like FH said, if you don't have the threaded adapters, you'll have to make some. If you can find brass or nylon screws, it won't be too hard to drill them. If you have mercury tubes, be careful, but I think you said you have gauges. When using gauges, you need to calibrate all the gauges with one vacuum source to be sure they're matched.

.........Paul

Bikegeezer · Posted: Thu Mar 11, 2010 8:13 pm Post subject:

It's not worth your time to jerk around drilling screws. Just buy a set. They're not expensive.
http://www.motorcycletoolchest.com/Motion_Pro_08_0013_5mm_Adapter_Tubes_p/08-0013.htm
These also come with hose restrictors to keep your needles from bouncing around.

Stu

jvandyke · Posted: Fri Mar 12, 2010 6:44 am Post subject:

Thanks, that's what I'm after. Much appreciated.
5mm is correct for my carbs then?

Bikegeezer · Posted: Fri Mar 12, 2010 12:46 pm Post subject:

jvandyke · Posted: Fri Mar 12, 2010 12:57 pm Post subject:

Now that I think about it, I probably have 5mm hollow nylon screws in a bench bleeding kit. Probably not 4 though, and probably not as convenient as the elongated one.......