That is a common problem that happens over many years. Be careful, the handle can only take so much although I have never seen one that broke. If your lucky you might be able to salvage the chain. Mark the timing and take the chain off and put it in a solution of diesel fuel to soak overnight. Hopefully the kinks will be out of it. If not try to take them out by spraying WD-40 on the stubborn chain links. All of them should be out otherwise just buy a new chain. Whether you put the original back on or a new one there is a few things that I do first. I always zero the cylinder speed in by turning the shieves out or in all the way (machine has to be running so be careful!) and then depending on wheather it's low or high place the lever inside the cab in the correct position. Now put your chain on (or just put it on like you took it off)and spray it with a special kind of spray (I've tried many things like graphite, teflon, silicon, etc.) a product called FlUID FIlM onto the chain and you may have to do that once a year (I do it at the begining and end of harvest) and that should solve your problems. Good luck.
