My suzuki intruder 1500lc only runs well with the choke slightly pulled out. It starts ok.

SOURCE: Suspected problem with choke.

hey apparently and did are two different stories draining the float bowls and cleaning the carbs are two different things the fact that the choke dosent change suggest the carbs are stopped up after sitting for 1 year clean the carbs let them soak in carb cleaner and blow them out with high pressure air, keep notes of the adjustments befor you dissasemble them (air screws)

SOURCE: 2002 suzuki LS 650 running lean at higher speeds, (off idle)

this prob happens allways in carburated engines that the car or motorcycle is running lean or rich . because the air - fuel mixture ratio is not right . so you should open the carburator and remove the air filter you will find two screws in the lower front section of your caeburator. you can adjust them by a screw driver until your car is smooth

SOURCE: suzuki 1500 backfires when decellerating. any

I had the same problem and i cleaned out the P.A.I.R valve and now the problen is solved. Also tighten up the reeds in it

SOURCE: My Suzuki Intruder 750 of 1985 is not running

It could be a stuck choke, but it could be a stuck carb float, or needle valve. You may want to pull the carb bowl off and check and clean.
Once you get the bowl off, you can use a can of spray carb cleaner to spray the needle valve (gas inlet to carb), and inside the bowl, any jets and around the choke. Also check your air cleaner.
While you're at it, pull the spark plugs, and check to see how they look. I would clean them with carb cleaner, make sure there's clean metal at the electrode and replace any that look questionable.

Testimonial: "Thanks This is indeed what I was thinking to do, the sparkplug looks dark thus to much fuel"

SOURCE: 2007 Suzuki Boulavard 650 s40 backfires

toneison, what did the dealer say?