Jumping throttle

[Autohuligano]

Hello!
I just bougth me an GS850 G. I?ve cleaned the carbs and I fire it up.
The 3 throttles to the left stands still while ideling, but the one to the right jumps up and down a little. It backfires to sometimes. I took out the sparkplugs and the spark to the right was sightly White, and the other 3 was black and allmost a Little wet.
Any ideas?

[Master077]

Did you synchronize your carbs? Are all the air screws set the same?

[tom203]

Welcome. head to this link for gs info overload and be amazed

http://members.dslextreme.com/users/bikecliff/images/GSR_Greeting.html

As you sit on bike, #1 cylinder is extreme left (under clutch lever). Sounds like #4 is running lean, while others are slightly rich ( hard to tell till it warms up).
When you say "jumps up", do you mean the linkage between carbs seems loose and revs are varying?

Be suspicious of previous owners' efforts- head to that link and read!