Choke tuning...

Yeah, you read that right... Choke tuning! Something is up with my 650 with VM24 carbs. They were from ebay and are giving me nothing but problems, anyways, I've finally sorted the jets (had to drop down a needle jet size to 0-4). bike runs great after you fiddle with the choke during start up. All verified with an AFR gauge.

Problem is that there isn't a choke position that works on all the cylinders. I have to oscillate the lever between 3/4 and 1/4 choke to keep all the cylinders happy until i can turn the choke off.

My plan of attack is to figure out what cylinder(s) arent running at a certain choke level and then tweak the choke lever for those individual cylinders. Any advice?

It is not an actual choke, it is an en-richer circuit, as long as the rubbers on the bottom of the plungers are OK and doing their job which by the sound of it , it is, the problem lies elsewhere, are the valves seating properly,is the valve lash set correctly, is the camshaft timing correct, are the points condensers and coils good, is the ignition timing correct, is it running with stock air-box and filter, if running pods have you installed air corrector jets, and main jets to suit, if after market exhaust is it completely open, are you getting 12 volts at the coils, are the spark plugs good.

You might want to check to see if the choke pickup tubes are open, and same thing for the passage through the float bowl for said tube. Shooting carb spray straight into the hole in the bottom of the choke plunger passage should result in carb spray coming out of the choke pick up tube, both out the tip of the tube and sideways at the base of the tube.

Thanks for the thoughts guys. Didn't see this till now because Gmail decided kzrider emails were spam again!

Did you vacuum synch the carburetors?

Carbs are synced. Bike runs like a top as soon as i get it off choke (enrichment).

AFAIK the carb pickup tubes are clean. The carbs were gone over many o times due to other issues.

Bike had no issues when running on the VM22 carbs. valve lash still fine. new carb boots as well.

I doubt this is the problem, but I had a pair of carbs for a 400 that were similar to the problem you describe. Turns out someone drilled out one of the choke jets with a 1/16" drill bit and left the other one stock. Never underestimate a previous owner.

:sick: The horror!