I just installed an FMF jet kit on a 2000 DRZ 400 . When it starts to warm up on the track (intermediate rider) it then begins to pop and backfire even when at altitudes of 5,000' or higher where you would think rich not lean. Think if I drop the clip 1 or 2 slots would help to enrich or trash it and go back to the stock jetting. I have a FMF pipe stock header stock filter with no top.
I have two 2000 DRZ 400's and just jetted them with the FMF jet kit. On the track ( intemediate rider) I am experiencing poping and backfire when it is warmed up. However this is also true at 5,000 and higher elevations. I would tend to think rich up at altitude but this is not the case. Do you think if I drop the clip to raise the needle two slots that would do the trick or trash it and go back to stock.