Motorcycle Repair: carburetor, yamaha roadstar, vance and hines pipes

Question
i have a 2001 yamaha roadstar with vance and hines pipes w/o the baffles. i get a occasional backfire. what is the best way to get rid of the backfire

Answer
Hi Rick.
 Backfire occurs when the exhaust valve is not completely closed during the firing sequence.  You can never really eliminate it completely.  That is why exhaust systems have baffles in them; to dampen that noise.  Removing the baffles changed the back-compression that you would normally get.  That backfiring as well as a noticable drop in performance and fuel economy are the byproducts of that change in your exhaust system.  Particularly when the engine was not completely retuned to compensate for the difference.

The closest that you may get is to set all of the valve gaps and ignition timing settings to the absolute minimum gap and dwell on the engine.  These things are normally done (along with about a thousand other things) when someone "blueprints" an engine.  Again, this will not remove the problem, but it may reduce it.

Good luck.
FALCON