Motorcycle Repair: run ability, suzuki gsxr 750, plug colors

Question
the bike is a 1991 suzuki gsxr 750 with stage 3 jet kit.. it has been stored with a full tank of gas with stablizer in it. last year i had the carbs cleaned and rebuilt. upon starting it up this year, i had a hard time with it idling and an occasional back fire. i fully emptied all the gas and floats. now it idles good not perfect. when riding it, i have little to no acceleration at any speed above 30 mph, it seems to bogg down...please help  thank you very much

Answer
Robert,

backfire in the exhaust usually indicates
a lean fuel mixture. In your case
since the bike was stored awhile
it may be the main jets or needle jet tubes
above the main jets that are still
plugged.

Is there a fuel filter?
Do the float bowls fill up quickly?
Is the choke functioning okay?
Is the gas tank vent clear?
Do intake rubbers have any cracks?
Check if carb slides lift up and down ok.

Before pulling the carbs apart
I suggest a compression check to insure
no rings or valves are stuck. See if all the cylinders
warm up at the same rate by checking the
heat on the header pipes.

Also try some new spark plugs and
check that nothing is blocking the air
filter.

Also have a look at the plugs
to determine what's happening by reading
the plug colors. Spark plug color chart is here:
http://verrill.com/moto/sellingguide/sparkplugs/plugcolorchart.htm
This can tell you if it is running lean or rich on fuel mixture.