I have a 96 F3 and when I went to change the forward sprocket and chain I found I could not loosen the bolt that holds the forward sprocket.

Any ideas on how to loosen the bolt, I tried a electric impact wrench and it didn't work ?

 

All I had to do was use a socket with a cheater bar. Just make sure you push the rear brake or you'll just spin it!

 

and make sure u still have the chain on the bike or else holding the rear brake wont help lol

 

Use one of those handheld blow torches (MAPP gas) and heat the bolt, but for no longer than about a minute or two or else you might melt your output shaft oil seal. When it gets nice and hot, hit it wiht that impact wrench until it breaks free. There could be some locktite on the bolt and the heat should melt it. Otherwise, the bolt is just being stubborn and the heat will aid in its removal. By the way, how much torque does your electric impact deliver? A good air impact might be a better solution.