Dj683 i installed bub pipes on my 2000 yamaha

It is not essential but the static timing may need to be advanced slightly to compensate for the different back pressure.

This is a very common problem fpr bike that sit over then winter and/or rainy seasons. From sitting too long, the old fuel in your carb bowls have plugged up (varnished) your pilot jets and probably you idle fuel mixture screws too. Luckily your carb bowls and jets can be access without having to remove the carbs. For about $4 each, sometimes it's easier to just replace the pilot jets. If any of this is foreign to you, have a shop do it. And don't let them get away with quoting your the same charge to do the work as a V-Star 1100. The procedures are completely defferent and alot more extensive on the 1100.

popping on decel is from a lean condition. More likely from a lean, or too small pilot jet.

If the mechanic did not replace the exhaust pipe gaskets in the head or on any connections between the head pipes and the mufflers , the air leaks could be igniting unburned fuel in the exhaust , causing the popping and back firing. Try replacing any gaskets in the exhaust system.
If you have a flat spot or hesitation when accelerating than you probably also need to rejet the carburetors. Bigger main jets should fix that condition. A jet kit may also contain differently tapered needles for the slides to help compensate for the change in the acceleration curve.

Re-jetting the carbs may be needed.
Imbalance of air/gas ratio will cause backfiring among many other things. :)

Other considerations:
Have the timing and valves set.

After market pipes will also increase the Poping sound when you let off the throttle. (not really backfiring but annoying)
Removing and plugging the AIS system will stop most of this.

Good luck!
Hope this helps.

yes

We have changed a few bikes from standard pipes to drag pipes. Their is a few considerations here, sea level or at what altitude, how much back pressure. so my suggestion rather take it before fitting the pipes to someone with a dyno, run and record the test, then have the pipes fitted, and let the same shop to the test again on there dyno, they will then know what to do with the jetting, because you should achieve better results with your new pipes.

did you get it checked for cylinder pressure? take out spark plugs, clean them out and observe for any oil or deposits

First off did you buy it new? Second has it gone through its break in tune up yet?Did you do the re jeting? My guess is it was re jeted wrong & neeeds to be re jeted again or could also need more air(upgraded air kit) or a tfi or power comand fuel mod.My bike also poped untill I did the air & fuel upgrades & them upgrades will also give you a much needed house power needed for this rig.


Bring it to a shop & have it looked at.......


Good luck