bs34 air mixture screw issues ?

left carb air mixture screw not the same as right carb . the right is a lot deeper than left ..gets snug don't want to force it. . They should seat the same on both carbs? also how the heck do you get the o ring out ..lol

ok I switched air screw and it goes tight on both carbs . One of the air screw won't tighten all the way down. Got new o ring washer etc to replace missing washer ..the screw that came with kit is smaller in length. Can I still use that one

There are several possibilities here. First, some rebuild kits had a mix screw replacement that did not match the original. Maybe one of those has been installed .....



Another possibility is that someone added a new washer and o-ring on top of the old ones. Or maybe someone broke the tip off the old screw, left it in there, and just put a new screw in on top. You'll need to pull the carb set to check this - screw the "good" screw (the one that goes in deeper) all the way in. Watch the outlet hole in the main bore as you do so .....



With the screw all the way in and gently seated, you should see the tip of it sticking out of the outlet hole. Now look at the other side. Is there a screw tip visible even though the screw isn't fully screwed in? If so then that's probably the broken tip off the old screw.

You'll need to "fish" the old o-ring (and maybe the little washer too) out of the hole with a pick or hooked piece of wire. Make sure you assemble it correctly when re-installing. The sequence from the top is spring, little washer, o-ring. The washer needs to be between the spring and o-ring or the spring will chew the o-ring all up .....

oh thanks a bunch great input …yes I have the stock screw. The one they gave me is the smaller one shown in pic ..I will try this and let cha know ..thanks!!

Yes, you want matching screws, either two originals or two of that new kit type, or you won't be able to match the adjustments (which you should) between the two carbs. Mix screws set the same or very close to the same is one of the things that tells you your carbs are functioning correctly. If you need to set one mix screw a lot different than the other for the bike to run, that usually indicates a problem present in one carb or the other. In your case, you would get misleading results using two different screws. They would be set differently (due to the screw differences) but not necessarily incorrectly. It would all be very confusing.

Same screws both are stock and matching .. …One doesn't come tight all the way … tried the good screw in both carbs and it thigtens down fully on both crabs …so the carbs are good ..I think the one screw has bad thread ?I ordered washer, o ring, screw but its different than stock ..pic above . So can I use the smaller screws if I match them . where can I get a stock screw from.. ty

Sent you a PM regarding getting a good stock mixture screw.

Thanks dog for screw it fits down ...backed it out 3 1/2 turns out ...cleaned carbs and got it to idle ...now its all over the place . One carb is leaking fuel float issue and back firing. choke off and it wants to die when I give it gas . ..time to tweak any thought s fellas?

www.amckayltd.com/carbguide.pdf Is a good place to start. It has the proper procedure to tear down, clean, inspect your carbs.
Once it's clean reassemble and set the float levels as on the spec chart.
There is a section on tuning. This will help you very close.
Leo

You won't be able to tune the mix screws and set idle speed properly until you fix that float issue. That carb is flooding out which will make that cylinder run too rich. It's probably also causing the idle speed fluctuation.

ok took apart part carbs and I'm good float is good ...she starts up and idles good ...just back fires now and not 100 percent ..not sure what to tweak next

Sync can do that, or rather out of sync. I would also go through all the tune-up stuff - cam chain tension, valve settings, timing (if adjustable), and points (if you have them). Everything needs to be right. Air leaks through the manifold or butterfly shaft seals are another possibility.