I HAVE AN 89 SPORT WITH A 1200 BENCH MOTOR BUILT TO MODEL A 1203 BUELL WHITE LIGHTNING, HER'S THE PROBLEM NEVER HAD A LICK OF TROUBLE, NORMAL STUFF, OIL LEAK, PLUGS AND WIRES, FIRED IT UP AFTER WINTER REST, HAD TO CHARGE BATTERY, STARTED FINE, RAN FINE, GOT OUT ON ROAD AND GRABBED A HANDFULL OF THROTTLE AND IT BOGGED DOWN, BACKED IT OFF AND IT WENT BUT BARELY ,HAD TO PLAY WITH THROTTLE JUST TO GET IT BACK TO THE HOUSE, SOUNDED LIKE IT WAS A MISSING, IM ALMOST SURE ITS FUEL BUT HEY.
ANY SUGGESTIONS WOULD BE GREAT, (ALSO WHEN SITTING IDLES FINE, IF YOU GRAB SOME THROTTLE IT REVS UP AND SOMTIMES BACKFIRES NOTHING TOO EXTREME)

 

Old fuel perhaps? Time for a carb cleaning?

 

FUEL IS GOOD I PUT THE HIGHEST OCTANE I CAN FIND NEVER CHEAP GAS, AND CARB IS CLEAN, CHECKED ALL THAT.

 

Check your battery cables for tightness on BOTH ends next. How long has the fuel been in the tank? All winter or did you do a fresh refill?

 

Just had the same problem. Turns out it was bad gas. Dealer suggested finding a busy gas station and using 93 octane. My current filling station isn't in a high traffic area. I wonder how the bad gas is impacting some of the cars.

 

Are there any other symptoms you may have noticed?

FYI, ALL CAPS is considered yelling. Good Luck.

 

I agree with the other posts that the most likely culprit is old gas.Anytime you're going to be down for any amount of time it doesn't hurt to treat your fuel with sta-bil or any other acceptable fuel stabilizer.It's not very expensive and a bottle goes a long way.I would suggest draining the tank putting in newfuel and adding a pour -in gas treatment to help clean your jets and carb.If you were only down for the winter it shouldn't be TOO bad off.

 

I agree also, sounds like a fuel problem. if putting new fuel or a octane booster doesn't work you may want to drop the bowl and clean out the jets manually. I know BG product has some great Carb/injector cleaners that works well. I never used in a bike but used it in cars and it cleans all gummed up deposits while the car runs (just put it in the fuel tank)

 

Mine did about the same thing . I unhooked fuel line from tank, put a funnel on gas line , poured in some SEA FOAM , ran motor until I could tell carb was full of SEA FOAM , killed motor , waited 10-15 min. cranked er back up , poured gas in funnel , she coughed and sputterd a little , blowed out some black smoke then went to running fine . Must of been a little trash or varnish in the main jet , maby this will help , good luck .