Fun with carb problems

Hello all,
Good news, the bike starts. Bad news, it runs like crap. I am figuring it is a carb issue because at one point I had the mixture screw turned out a good amount and it would idle fine but had zero low end. That is, when you got mid way through the gas it would take off, prior to that it was boggy as hell. I decided to start again with the screws 1 1/2 turns from level, but now it will mostly only idle with choke on and the stupid carbs spit at me, I think it is very rude indeed. Anyhow, I have tried to bench synch the carbs all to no avail. I can read vacuum gauges, but they do not even register an amount ( swings wildly about 0 up to about 20cm Hg). Just for some background, I rebuilt all the carbs so they are pretty clean and also, I am running pods. I did level all of the fuel bowls as well. as usual any advice helps.

Gauges won't work well for syncing carbs unless they have dampers on them. Also, does the bike have the stock air box and filter on it? Ed

Hey Ed,
No air box, I have pods on. Thanks for the info on the dampers. I will pick those up. I have a quick question about bench synching. When starting should the screws be all the way in or out or in the middle? I have no idea what the starting position is supposed to be.

You start with the screws all the way IN and back them out by so many turns ( It,ll give you the amount of turns in the manual.). Thatll give you a starting point,.
Fun,fun,fun.
good luck

P.S. Im not a mechanic.

Hi Eddy
Thanks for your information on dampers.

For bench syncing you normally use a piece of wire as a gauge between the bottom of the slide and the carb body to make sure the slides in all carbs are at the same height when the throttle is closed. Ed

What kind of bike, carbs, year etc.?

Your idle circuits are dirty / clogged.

on my manuel...it said to adjust the idle screw in 3mm or half way in and 3mm between the slides and carb body.
set this way starting rpm was about 2200 and was able to adjust it down.
really you need to check all o-ring ...need to be in good codition so not to loose any vacuum.
i will never use a used set of carbs without a proper cleaning and a complete gasket set.

Ed, I was able to use aquarium air valves for dampers on the gauges. They work well and only ran $0.35 each. Thanks for the heads up. Also, I was able to get carbs synched. but as I have posted in a new thread, I have no low end in 1st gear. Anyway, thanks for the advice everyone.

That's a great, inexpensive solution for anyone who needs the dampers! Ed

baldy110 wrote: Your idle circuits are dirty / clogged.

A good cleaning using Patton's method, a new set of carb holders and turning the air screw out another quarter turn 1 and 3 quarters cured my slight hesitation off idle. I always thought it was something I had to live with since I ran the pods and header but maybe not.

The air adj screw never seemed to do much for me .... might and am 90% sure the cause was the leaking carb holders and or dirty idle circuits.

I tried 1 and a quarter and 1 turn out and it ran worse so I needed it opened up a little. Have a color tune that I havn't used yet and plan on getting it out next year to get em closer.