whats wrong with my carb

[Anonymous]

i have a 78 gs 550 vm 22 carbs ,bike hasent ran for atleast three years till now .the problem is i rebuilt the carbs bought a mercury sync did that ,bike seems to run good exept for #4 is getting way to much gas ,it backfires on every revolution but not really bad just makes the pop pop,plug is wet with gas ,and it smokes out the right exhaust on open accelleration , turned the fuel metering screw all the way in even took it out completely after trying the 1 1/2 turns out from slightly seated.so my question is what am i not doing right and if i cant get it figured out will this harm the bike by riding it . any info would be greatly appreciated. gump!!

[Dink]

sounds like the needle valve is not closing allowing continual fuel flow.
I would check for a sticking needle valve in that carb first, possibly could be the float level being to high, and an old mechanics trick that may help is to polish the needle tip with normal car polish supposedly it stops them sticking.
Dink

[Anonymous]

whats wrong with my carb

the needle valves are new ,i guess ill check the floats,fuel metering screw does that have anything to do with too much fuel. the haynes manual i have dosent really say much about it accept must not be removed !,i sure wish they would have described its function.is there another name for it ?what does it do? the reason i ask is because when i took the carbs down they were just covered in varnish so did a complete soak and bottom rebuild ,when i took that one out the tip was broke off ,got the tip out and had to get another one at a salvage yard because three suzuki dealers had no idea what it was and couldn't find hide nor hair of it in the books . once again thanks for your ideas.

[argonsagas]

First, try Dink's ideas.

Sounds like you are getting too much fuel in #4 and/or not enough air, but I cannot see an air restriction for only one cylinder, unless you have individual filters.

If you get the floats perfected, and find nothing more to do with that area

then try pulling off the carbs completely, loosen off EVERY adjuster ...repeat EVERY adjuster....including idle setting....and do a visual carb balance after that.

Catch 22...
On some carbs, including mine, you cannot accurately set # 3 until #4 is properly set, and once #3 gets well off, you may not be able to do much when the engine is running because the idle screw has to be completely free of all contact before you can set #3 and 4 carbs properly ......that means you are back to pulling the carbs and doing a visual set-up....

Running rich can cause problems, but is not likely to do much harm to the engine, while quite the opposite is true if you run too lean....be careful with the mixture screws/settings.

[Anonymous]

By the way, the "factory setting" on the pilot mixture screw (on the bottom of the VM22 on the GS550) is 2-turns out. I haven't found the setting to change if you have pods or larger mains.

There is no spring to hold the setting in place, so put some blue Loctite on the heads. You shouldn't have to mess with the screwe ever again (thank god, because it's absolutely inaccessible).

[Dark Jedi]

By the way, the "factory setting" on the pilot mixture screw (on the bottom of the VM22 on the GS550) is 2-turns out. I haven't found the setting to change if you have pods or larger mains.

There is no spring to hold the setting in place, so put some blue Loctite on the heads. You shouldn't have to mess with the screwe ever again (thank god, because it's absolutely inaccessible).

This advice got me started again after I played around with these. Good tip.