I’m getting engine misfire from about 3000-4000 rpm when in neutral or on load. I’ve noticed this for quite sometime but seems to be getting more prominent. Anyone have this problem and what did you do to fix it? or is it normal?

So far I’ve tried the following with no luck:
Cleaned air filter
New spark plugs (factory like-kind)
Fine adjustments on tuner

2012 Renegade Xxc 1000
VFJ Mods:
Slip on Muzzy exhaust
Clutch Kit
Digi-Tuner