Carb Sync - "bouncing" readings ???

[F6CTrider]

Just learned how to, and did a carb sync this am with my neighbor (Thanks HC!).  While we adjusted the carbs the vac reading was bouncing up and down.  This was not the experience when my friend did his bike.
????
Any experience with this out there?   Is there another issue to pursue?  I am now replacing a few of the overly cooked vacum caps to keep away from any leaks soon to be developing.
Perhaps my carbs have a nervous condition?

[LAnthony]

My set has little in line reducers on each of the lines that you tighten up just enough to stop the bouncing.  The mercury ones don't seem to bounce as much as the guage ones do.  This is just the intake valve opening and closing, reducing vacuum readings for a split second.

[fudgie]

I went to the hardware and bought a brass needle valve. Hooked it up between carn and gauge. I slowly close it till it stops bouncing. easy $5 fix.

[bigfish_Oh]

Is everyone using liquid filled guages ? I still have access to 6 tubes of mercury(I traded to my brother), but have saw on other sites the homemade tubes with ATF . I think I will make a set first just for the cheap challenge/test !

My PMS is getting bad

[fudgie]

Is everyone using liquid filled guages ? I still have access to 6 tubes of mercury(I traded to my brother), but have saw on other sites the homemade tubes with ATF . I think I will make a set first just for the cheap challenge/test !

My PMS is getting bad

You make it over to Indy?

[bigfish_Oh]

We went over, I liked it better than the columbus indoor easyriders, I'll still give an outdoor easyriders a go !! I saw a couple things of interest, Rebecca tried on a jacket she liked, then I ordered the same one when we got home that she doesn't know about yet($30. less). I bought more raffle tickets, I better quit, I can't afford the income tax on 4 new Harleys !!!

[Patrick]

I guess I need to know what you mean by bouncing.. If the gauge doesn't have any provision for dampening[  pinch screw ], then you can just add one.. A little valve or forceps will do, all you need to do is cut down on the pulsations, pinch or restrict the line until the needle just barely wiggles..

[highcountry]

I did F6CTrider sync with my Twinmax and the needle would vibrate instead of remaining steady.  When I did my bike about 6 mos ago, I don't recall the needle vibrating but I have slept about 180 nights since I did it, maybe I forgot.   It was easy to center the needle even though it was vibrating.  It did the same on all cylinders.  I was wondering if there was some kind of vacuum pulsing going on.  F6CTrider's bike does have a 6 degree ignition wheel and mine does not.