when cold, or when i honk on the throttle, the little devil seems to backfire through the carbs. had this same problem when I had dual weber setup. any ideas?

If your carbs are in good shape, the mixture is correct, and they are well balanced, the next place to look would be the timing. It might be a bit too retarded and causing the backfiring.

How long since you did a good thorough tune-up of all the engine systems, ignition and all?

Like the man said check the timing first . If it is ok then ballance the carbs and check that the mixture isnt too lean , it could be a lean pop. Check the oil in the domes , and add if necessary with 20wt if you have it . Other wise try 10-30 untill you can buy some 20wt fork oil. One other thing you dident list where you are. If in cold area how does it run with the choke on ??

Hey Beandip, i am having the EXACT same problem on my 260, and it runs fine with the choke on, has been a while since tuning, suggestions going forward?

Thanks,

Zlish

It sounds like you are either too lean in the settings or that you have too thin of oil in the carb. dampeners. Do try 20wt in any event , in santa rosa that should be pirfect for all year long. You can find it at a Motor Cycle shop . Ask for fork oil . All the best to you and y ours