Motorcycle Repair: 1984 FXRS, fuel air mixture, variable venturi

Question
SEAN, I RECENTLY BOUGHT A '84 FXRS THAT HAD NOT BEEN RIDDEN FOR THREE YEARS. IT WILL START AND RUN BUT DOES NOT IDLE. IT BACKFIRES AND BLUE FLAMES COME OUT THE BUB EXHAUST PERIODICALLY (I LOOKED INSIDE THEM AND THEY ARE HOLLOW TUBES, NO BAFFLES/MUFFLERS). IT ACCELERATES AND HAS POWER WHEN RIDING. ALSO, IT HAS A LATER MODEL CARB WITH THE VACUUM ACTUATED VARIABLE VENTURI. ALSO, IS IT NORMAL FOR EXHAUST PIPES TO BECOME RED HOT NEAR THE MANIFOLD? THANKS, RAY  

Answer
Hi Raymond,Try cleaning your slow idle jet, if it has been sitting that long.The blue flames could be a jetting  and or fuel/air mixture problem.The exhaust does get red hot at the exhaust ports and is primarily only at stand still,for they are air cooled.