XR400RMan
1. Doesn't the clutch get hot and wear out quickly?
Yes the clutch will wear out much faster than if you don't fan the clutch, however the benefits while racing are worth it.
2. Do you have to slip(or FAN)the clutch as some people call it?
My bike (99 KDX) needs the clutch slipped often when I race MX. It gets the bike out of the turns much faster. Whenever the bike is out of the power band its easy to get the bike into it.
3.Don't you guys on 250's,125's have to replace your clutch plates more often than say I would on my XR250R?
Slipping the clutch will wear it out. Your XR250R has a completely different powerband than most 2-strokes. If you have a pipe that gives the bike more power at higher RPM and you race fanning the clutch wll make you faster, however, if you bike comes off the bottom (low rpm) with good response slipping the clutch will not buy you much and just wear out the plates faster.