carb sync

[art]

I tried to sync.the carbs with a gage that I bought from harbor freight but the needle swings all over the place .the vac. is not steady  it  puffs air out then draws vac. so that I cannot get a reading.Any ideas on this ,has this been a problem with anyone else or is it normal? Art

[Dave Weaver]

It is normal, Art.  Take a pair of needle nose pliers or vise grips and squeeze some pressure on the vac. line below the gage until needle smooths out. 

[BamaJack]

I tried to sync.the carbs with a gage that I bought from harbor freight but the needle swings all over the place .the vac. is not steady  it  puffs air out then draws vac. so that I cannot get a reading.Any ideas on this ,has this been a problem with anyone else or is it normal? Art

I use some valves from a fish tank in line. Start with the valve open and slowly close it until the gauge stops wagging. 

[Ken Tarver]

fold over your tubing and use a clothes pin and adjust till the needle stop twitching

[Patrick]

What your seeing is normal and what the boyz told you is correct.. A vacuum gauge that has a damper screw slows the pulses in the same manner, it just pinches the tube.. You want to pinch the tube just so the needle wiggles a little bit..

[Dag]

Its not normal....
I have built several carb tune units and I have never had that problem.


All liquid filled vacuum gauges should have a rubber tip on top.
You have to either cut the tip or take the rubber top off when using the gauge.

[art]

thanks I'll try that an see

[Ken Tarver]

now look what you gone and done with that case! Now I see a rebuild here in the shop....I like it Dag, that is nice.

Ken