carb balancing

[jddevel]

TF1500. twin 1 1/2 sus just changed cork gaskets. Gunson set on rear carb. with obviously engine warm and running. Move it to front carb engine stops. Link between the two obviously disconnected. Am I now to rich or to lean on front carb please?

[Rob Reilly]

A google search of Gunson turns up a Colortune spark plug tool.
I have only used a Uni-Syn for balancing carbs.
If my tool were to stop an engine I would think the throttle plate is closed.

[Duncan M]

Gunson carb balancer looks difficult to use. https://www.gunsonshop.com/contents/en- ... ancer.html
I agree with Rob on the utility of the Uni-syn (floating ball). Once you get the gate set to your flow range, it is simple to go between the two carbs to get perfect balance.
https://www.amazon.com/Uni-Syn-Carburet ... B073RPZKBX

[Mark Strang]

Been doing SU's for 55 years. Use the Uni-syn. It will always work if there are no leaks around the shafts. In a pinch put in your hearings aids and use a hose to synch them!

[Steve Simmons]

I've found the Uni-Syn to be a little flaky / finicky sometimes. I prefer the "snail" type. It's very accurate and no adjustments are ever necessary. Mine is similar to the one below.

[Duncan M]

The erratic readings on the floating ball uni-syn usually indicate a vacuum leak somewhere.

[Steve Simmons]

I haven't seen erratic readings because of the type of tool, but I've had some of them where the disc couldn't be adjusted properly, and I had a couple where the plastic tube cracked when it got old. The other type is easier to use and more accurate in my experience.

[jddevel]

Thanks all. Now another problem. See new topic

[Duncan M]

Steve, I am saying the old standard floating ball Uni-syn is useful for spotting vacuum leaks you might not be aware are there. As in a vacuum leak at throttle spindles or gasket. Otherwise the floating ball works great. Not sure if the snail type can make the same claim of acting up in a characteristic way-- when there is an otherwise unknown vacuum leak?

[Steve Simmons]

Hmmm, not sure really but they do essentially the same thing just with a different reading. The snail type, or at least the one I have, has a bit of damping to it so the reading changes just a little slower than the Unisyn. That might be a disadvantage for the test you describe.

[Duncan M]

I must be explaining myself very poorly. Next time you have a car that you know (already figured out) the throttle shaft is causing a vacuum leak, or that you know the carbs intake gasket is leaking, try the floating ball Uni-syn and you will see what I am talking about. Of course there are other ways of spotting intake leaks, such as spraying carb spray on the throttle shaft ends and on the gasket area to look for RPM increase to indicate vacuum leaks.

It used to be a known thing that if a car was running poorly, that one of the first things you could try was sticking a unisyn on each carb and looking for the erratic floaty ball. If the ball was behaving normally, and smoothly rising up as throttle screw turned to increase RPM, etc., then you likely did not have a carb (vacuum leak) problem

[Steve Simmons]

Yeah that's what I mean, the other tool I have reacts slowly, so if the airflow was erratic then it might not show up as well as on the Unisyn, which reacts very quickly.