wheelies and questions

i can hold it up in second for a pretty long time i get pretty high i clutch it up in 2nd a little under 25 mph, when i feel myself about to rev out should i switch to third to hold it longer? i currently have a 2013 wr250r converted to an x, where can i get a blue oem rear fender? can anyone provide a link?

Shift to 3rd

You have to either keep accelerating or keep it at the "balance point".

When you see guys wheeling bikes that don't have a lot of power on tap (50cc pit bikes, 100cc trail bikes, 50cc scooters, etc.), especially for a long distance, they are balancing it with the throttle and rear brake.
A WR-250X will accelerate only so far before you need to use balance to keep it going in a wheelie.