I've been searching and searching and searching for answers regarding bike performance, HP #'s etc concerning all mods for my 1997 YZ250?? and found nothing really concrete. I have now found a lot of talk about these Noleen pipes for the 97-98 YZ250 and how they made the bike so FAST? What kind of difference am I going to see from my current pipe (running a FMF gold series fatty)...... Can I get HP numbers on my year of bike stock? where can i find that info, I heard 41HP, can I acheive 50-55 HP out of this bike without a bore job? Can anyone give me info regarding modifications.