Your bike is NOT backfiring, she is popping, backfiring is(was) when the unburned mix at the carb was able to ignite and explode back too the air filter.

As Andy12 says, the popping is due to the AIS, there are 3 ways to stop the popping.

1. blocking the AIS intake.
2. removing the AIS completely and tapping the AIS hole at the head and the air filter hose.
3. keeping the AIS valve closed all the time, you need to connect the AIS valve wire to ground, very easy to do under the seat, but you need to cut the brown/red wire and connect the non-ECU end to ground.

have fun,

j.

The AIS is controlled by the ecu but also like mentioned here before it will open

Considering your Avatar, it's good to see you here.
I always enjoy your inputs at Fullgaz.

Sorry if I'm wrong.

You got me :sbike:

I removed the AIS plumbing last week - fitted a rubber bung in the airbox hole and made an alloy plate to cover the inlet between the manifold - and can confirm this has all but cured the backfiring you experience when snapping the throttle shut...

Fortunately the ECU does not flag up a fault code if you simple disconnect the AIS solenoid plug - there is a routine on the diagnostics to test the solenoid is working, but not an actual fault to say it's not (I trust Yamaha knew people would probably want to disconnect this, so made it easy?) - result!

Once you have blocked the two holes, you ought to have no problems, and no popping!

xxx

This is now on top of my to-do list. Then I can put back my slip-on, the backfiring was deafening with it on. =)

My XTX does this a lot; I have to say though that it doesn�t really bother me, I actually quite like it.

One of those strange fetishes that we all have I suppose? :eusa_shhh:

It is reassuring to read that others have the same though and it does not indicate a 'problem'.

Me 2.