Is it bad to jump-start a dirt bike and if so what does it do?

As long as you attach the cables to the dead battery first, be sure of the polarity, Remove the cables from the good battery first you should be OK. The thing to avoid is sparks around a dead battery. A battery that is charging heavily (like when it is dead) emits hydrogen gas. Hydrogen is very explosive. Watch those sparks so no explosion that can ruin a good day and the bike.

you can damage the clutch, but it's not too bad, if you do it alot it will wear down the clutch plates after a while.

but if you just have a flat battery and need to charge it, onece in a while is fine, no worries

if you mean jump -start as in jump battery like with a car yes it can hurt the starter. its not meant to take that kind of amperes. but you can jump with a norther bike. if you mean run and jump on no it cant hurt it damn tuff .

It's hard on second gear but what isn't. Over an extended period of time you'll notice the wear so fix the kick-starter. People who are talking about using cables and nuclear explosions and what not should leave the discussion

I agree with the others. Dirt bikes are pretty hard to damage. I know the term as "bump start". Jump start with cables.

Nahh it's fine Dirt bikes are built to take pounding you won't hurt it.

no it wont hurt it. did I miss part of the question where did he say he had a battery problem?