I have a 2001 xr650r uncorked, side drilled, uni filter, and just put on a white bros pro meg. It seemed sluggish in mid to high revs, so I changed the 175 main to a 180 and moved the needle clip to #4 down. It really woke the bike up, and dosent show signs of being rich. I have a 70s slow jet on order, and am thinking of trying a 182 main just to see. What confuses me is that I am running at 5500 ft, and all the info i see says this is too rich. I know that some of you guys running at sea level are only running 175 mains. Any thoughts? shoud I try a 182 or 185 or is there something im missing? I would also like to thank all of you experienced guys for helping out us newbies, thanks!!