82 Maxim Idiling Very High

Just got this bike. Its actually my first motorcycle although i do have a little experience tinkering with them. It starts fine and runs well. But after warming up if I leave the choke on it will idle very high. 4krpms or higher. After I close the choke it idles ok but sometimes sputters out. Sometimes I will rev the throttle and it will go up to about 4k or 5k and just stay there. Could be the throttle I suppose but it doesnt look like its getting stuck.

Also, i have played with the idle control screw and it works fine. I can get a good idle with the choke off but it will still stay above 4k when i rev it.

Any suggestions? No idea if the carbs have been cleaned. The bike looks to be in great shape. Do you guys think cleaning them will help?

Thank you!

 

It may take more than a cleaning. You may need to rebuild them. May take some parts. Floats should be set.
The valves should be set first then sync the carbs then colortune then sync again and colortune again and if it still acts odd then this is where you would remove the carbs and start messing with them.
It is going to rev high with the choke on. This is actually a good sign. It lets you know that the starter jets are not clogged. As for the idle sticking.... check your throttle cable also. Make sure it isn't the cable that is sticking.

 

Clonk test - make sure that the piston/diaphragm operates freely - and go down with a 'clonk'.
False air - check the rubbers for cracks.
Enrichment circuit, clean it out + well clean it all up while your in there!