ok i have a 02' trx 90. its fast an fun an all but wanna make it faster. i've already done everything to it that i can jet the carb, exhaust, pod filter, cams, bigger bore, gears. but i thought i read some where that you can use a cr80? engine? dont know to much about any of the other motors but is it 2 stroke or 4? will it bolt right up? can i use my carb an exhaust? let me know or if there is a differnt engine? thanks