Motorcycle Repair: REAR CYLINDER CARBONING, rear cylinder, softtail

Question
I HAVE A 96 SOFTTAIL WHEN THE CHOCK IS ON THE REAR CYLINDER PIPE STARTS TO BLOW BLACK SMOKE PULLED SPARK PLUGS FRONT WAS TAN BLACK REAR WAS CARBONED  

Answer
Hi Steve, With the choke pulled the exhaust is going to be richer. The choke is really only for initial start up, try not to let bike idle too long with choke on. Try using the throttle stop at the grip to hold the idle while warm up.For the difference in plug colour check for an intake and or exhaust leak, pull your air filter and see where the fuel stream from the accelerator pump is sraying(possibly more to the rear cylinder)in your case. Good luck.