air screw adjustment

[Guest]

my bike is a 77 gs 750 ive only had the bike for bout 5 months and just recently completed all the standard maintenance, valves, carb dip, timing ect ect. seems to be running pretty good, fires right up, holds idle, runs a little choppy. ive been trying to adjust the air screw and according to everything ive read i should get some kind of reaction from turning it in or out. im not getting anything except if i screw it all in it starts to kind of choke out. ive checked for air leaks and dont seem to have any, the fuel screw is set one turn out from seated. carbs have not been synced yet, any input would be greatly appreciated

[tkent02]

Synch the carbs first, then try the air screws again.

[Steve]

Any mods to the intake or exhaust?

If the bike is stock, one turn out on the fuel screws might be a little too much. For a stock setup, 3/4 to 7/8 turn usually works well.
For pods and/or a header, 1 to 1 1/4 turn out would work better.

Whatever you end up with on your fuel screw setting, start with the air screw at double that setting, then be ready to fine-tune it from there.

Whatever you do, though, sync the carbs first.

.

[trippivot]

Carb dip? jeesh is that all ?? Berrymans is not aggressive as chlorinated cleaner and compressed air -- Plus a tiny wire is sometimes needed to mechanically remove the varnish.

There are a lot of details to set and consider when doing carb service. What are the float heights/fuel levels and are they identical among all 4 carbs?

there are tiny passages both for fuel AND air that need to be completely open

less than 1 turn you may need a bigger pilot jet -or the fuel level is wrong - or the fuel portion of the pilot circuit is plugged- over 3 turns and you need a smaller pilot - or the fuel level is wrong - or the air portion of the pilot circuit is plugged.

[maddoghoek]

by carb dip i meant complete teardown and cleaning new rubber according to the basscliff site. just waitin on sync tool, thanx for the responses

[hugo151]

hello, which way do you screw it to make it richer ? my bike is needing a bit of choke to run correctly even after its properly warmed up.

[tkent02]

Open the fuel screws another 1/8 turn or so. CCW.

[GSX1000E]

Any mods to the intake or exhaust?

If the bike is stock, one turn out on the fuel screws might be a little too much. For a stock setup, 3/4 to 7/8 turn usually works well.
For pods and/or a header, 1 to 1 1/4 turn out would work better.

Whatever you end up with on your fuel screw setting, start with the air screw at double that setting, then be ready to fine-tune it from there.

Whatever you do, though, sync the carbs first.

.

THIS is the CORRECT information to follow on you 1977 bike. Apparently some of the posts after STEVE did not read that you have a 1977 750.

[tkent02]

THIS is the CORRECT information to follow on you 1977 bike. Apparently all the posts after STEVE did not read that you have a 1977 750.

What makes you say that? He says in the first post it's a '77 750.

[GSX1000E]

What makes you say that? He says in the first post it's a '77 750.

I apologize to you as you also read it. You merely suggested (basically) the same thing as Steve. Which is, of course, also correct.
HE DOES NOT HAVE CV CARBS. on his '77 750.

[maddoghoek]

a bit of a update synced the carbs, played with the air and fuel screws a bit, got her purrin and roarin. just waiting on weather to get her on the streets to see what else i gotta do, thanx for the help

[chuck hahn]

Bottom pilot screws at 7/8 out and the side mixture ( what some call air ) screws at 2 out. You do the fine tuning with the mixture screws after that initial get it going setup.

7/8 on the pilot screws are as close to optimal that ive been able to get them on my 77 750. Much lower than that and its too lean. At 1 full turn out its rich and a waste of fuel actually.