I have an 85 with less than 10,000 miles that I just bought from the original owner and everything is sweet - except an annoying backfiring issue that starts fater the bike warms up, seems to persist on acceleration and steady cruising - funny, doesn't happen near as often when decellerating as I would expect. I read where this might be caused by the Air Control Valves in the carburetors? Any suggestions would be greatly appreciated.

Vince

That or intake boots leaking air, maybe even a vacuum leak...

Check for Vacuum Leaks on the Intake, put a shocj Dose of Fuel Cleaner in the Tank, ride for some Time to get the Cleaner into the Carbs and let it sit over Night, then ride it like you hate it.

Air Cutoff Valves are an Option though, but i'd do the other Thing first

Okay, made a short checklist and will get to it, I appreciate the responses. Supposed to be a good weekend for riding, hopefully get this cleared up quickly.

Take a propane torch (without lighting it) and just move the nozzle around the manifolds, heads and the carb boots.

If the engine RPM picks up, you have a leak in that area. This is an easy way to find leaks in an intake system. Other have recommended cab spray, but that's asking for a fire. This is much safer.

THanks for the idea, that's the easiest way I've heard so far, I'm on it.

MsRandiGalves wrote:


Randi,

That 'asking for a fire' part--Do you have personal experience in this area ?

Sparky