It sounds like perhaps over fuelling. Have you tried running it without the power commander connected?
No I havent unplugged the tuner, mainly because the bike wasnt doing this when I bought it and the tune hasnt changed. Other than the backfiring the bike runs great.It sounds like perhaps over fuelling. Have you tried running it without the power commander connected?
Yea I do ride spirited for sure. The bike does backfire at ~4000rpm on decel pretty much no matter what, but it is definitely worse when the throttle was high before fulling letting off. Sometimes even medium throttle, followed by zero throttle produces a pretty loud backfire.That kind of backfiring is usually (always?) excess fuel that gets ignited in the exhaust system by a hot spot in the exhaust or maybe on the exhaust valve. It would be worthwhile to try it without the magic tune box just to see what happens. Would you describe your riding style as "spirited"? Stated differently, lots of throttle followed by zero throttle?
Supposedly the PO had my bike dyno tuned, however I am in doubt that they attempted to properly disable the PAIR system for proper AFR ratio. The PAIR system artificially raises the AFR due to the O² being introduced to the exhaust.Pushing your hand against the exhaust outlet at idle should stall the motor, if it won't you have a exhaust leak.
If you think you are running rich looking at the spark plugs will give you the answer.
Due to valve timing and overlap there will be some raw fuel let past into the exhaust, raw fuel in a hot exhaust with a open end can cause the fuel to detonate, the length of the system and how open it is will play a big part.
I guess you don't want to spend the cash but I would recommend you put the bike on a dyno, the performance gains can be huge and well worth the cost.
I fitted a PCFC to my V2, the result was OK but I wanted more, I spoke to my dyno guy and told him I wanted to shred rear tires and loft the front wheel with a twist of the grip, he got that for me.
If I'm still backfiring after the above recommend tests, I would pretty much be ready to send the injectors off for a rebuild/flow match. Thanks.I had this problem and tried EVERYTHING! Turned out I had an injector that wasn't shutting off completely. I could smell the rich condition from the exhaust. Just another thought of a place to look.
Unless you have a local shop, I was impressed with price and service from The Injector Shop: Fuel Injector Parts, Rebuild Kits, o-rings, seal kits,If I'm still backfiring after the above recommend tests, I would pretty much be ready to send the injectors off for a rebuild/flow match. Thanks.