After I did some mods to my carburator keihin cvk, I heard strange noise under my sit. I figured out that my ATV needs more air. I tried to drive without airbox cover and motor runned much better.
With limited space I couldn’t just change intake tube, so I drilled 2 25mm holes.
Around holes I put some hot glue, so water can’t go directlly in airbox.
Wrapped airbox cover with nylon socks, so dust and stones can’t be sucked directlly in airbox.
This is how it looks in the end. There are much better acceleration and power.
After drilling holes you must adjust carburator with mixture screw!!!