This has really not been much of a problem, but does anyone else have an engine backfire occur when coasting down from a moderate speed (40MPH). This only seems to occur after the release of the throttle and coasting a bit, but happens regularly. I don't know if this is a too-rich or too-lean or other type symptom. I know some people are having problems with the choke cable sticking. Engine performance is fine and I get about 70 miles to a full tank.......

 

I had one backfire like that.

 

I ride with several others with 650's and none of us have experienced that.

 

My 650 is 6 weeks and 400 miles old. It has backfired under unloading conditions from the beginning. Its a lean condition and should be adjusted by a competent mechanic (dual carbs, you know). I intend to get it done as soon as I can part with the bike for a few days.

 

If this is the case, can I confirm it by applying a small amount of choke to force a richer mixture and seeing if it has cleared itself? I did not have any back-fires last weekend at Tellico. (Higher altitude)?

 

Likely the pilot jets. Richen them up a size and I bet that helps.

 

An easy thing to check for backfiring out of the exhaust is the head pipe flange nuts (cylinder head to exhaust) & the clamp from head pipe to muffler......make sure they are tight......dont go crazy & over tighten them.

These items being loose will cause the backfiring you all speak of.

 

Just wondered if anyone has had any success trying what I suggested in the post above????