what are the dangers of not jetting after yuou put on a pipe? if any

 

Well a pipe shouldn't be too much of a risk but if anything else(like airfilter&such)your engine may not get enough fuel and burn up a piston.

 

your bike would run lean and fry the piston and score the cylinder. and it would probably backfire alot.

 

If you dont jet, you wont be getting your moneys worth out of the pipe. It will only cost about 20 bucks to rejet...after spending 2 or 3 hundred on a pipe, itd be foolish not too.
Just adding a pipe wont help much...you need to improve breathing on the intake side and then jet for the increased flow. All 3 need to be balanced, or it wont run its best.
Heres agood site on rejetting, and youve got help here, if you run into problems. Or find a friend who knows his way around carbs, and have him show you how to do it.
Pay attention to the sympoms of running lean, thats what can cause damage, and bad drivability.
jetting