Bough 08 KFX with many mods, need help/got ques..

[twincat800]

I just bought this quad has the following upgrades: DASA Full Exhaust, Stage 2 Hotcams, Larger coil, ported and polished head (dont know where from), Je 12.8:1 stock bore piston, Power commander3 and some sort of aluminum intake box (looks good, custom all aluminum but prob not good for power), dyno tuned and air fuel waves between 12.7 and 13.2 (so it seems ok). 1st ques: Quad felt good and powerful but after riding a little while for sure lost power, do you guys think the exhaust making the aluminum air box couldve signifacantly couldve slowed the quad down (the air did get a little cooler if that helps)? By slowed down im talking having trouble beating a friends stock 09 yfz450 with baffle out and lid off. 2nd: for having all these mods it seems like it should be faster.. i have a dvx400 built (47hp 31tq but dynos read different) but technically not as built as much as this thing and it just seems like it should be faster.. a guy with same mods but stock piston and FCI intake says he got 51hp and with these mods that what I would honestly expect but it doesnt quite feel like it?My problems could just be my intake not being as good as the FCI which im sure i will eventually get but let me hear everyones input on what i have for now. One last thing, after shutting it off the fan did come on after about a minute maybe? and stayed of for what seemed like a long time, maybe running too hot, idk?