Slip on power pipe

[DRC]

I have just fitted a Vanceandhince power pipe to my 08 WR250F is says standard jetting is ok how do i know if i have to change it. I have a 45 pilot jet as a spare and the clip is in the middle

[JSanfilippo]

If its lean off the bottom, initial throttle response will feel flat and it will pop on decel. (assuming the AIS has been disabled or removed. If not it'll pop anyways)

If it is lean in the middle, the engine will rev too fast and go through that range with "hollow" power. Think empty revs.

If its lean on the main you get that flat feeling power and if you're more than a size off it might crackle and miss (like a loose airboot or something).

If the stock jetting is in the bike, its likely too lean. The instructions to the pipe I bought said the stock jetting was fine but that wasn't the case at all. It was actually off 1 size on the pilot and 2 sizes on the main.

[DRC]

when i got the bike the main was standard and the pilot was45 and the clip was on second from the bottom should change back it was too rich with standard pipe down low