Yerf Dog cout question...

[troutfishing15]

Bought this cheap for 1500 had only 30hrs on it and practically ment condition. I wanted something i could go in and take my treestand or drag a deer out with. Im a college student so this is the most i could go. I know there out of business and can still find a few parts. But the unit has a chain drive and when you press the gas it kinda jumps when you start rolling. It has a chain tensor on it and didn't know how these mechanisms work and how i could make it be smooth or was this a problem these units had

 

[fixit1ddh]

Mine kind of jumps in reverse. But going forward it's fine. My Brother had one and it was the same way.