I've been having issues with my Big Boss since last fall. First thought it was the cold, then it appeared the CDI was shot, there was a crack in the case and at that time I could not get the stupid thing started at all, so it seemed to make sense. Almost $300.00 later it starts, but won't stay running. I replaced the drive chain as it was very stretched, Then I cleaned the carb, etc.. It helped but would not stay running unless I held the starter button on. I replaced the Handlebar switch, another $100 down the toilet, Now at least it will stay running in drive, however sometimes I do still have to toggle the kill switch in order for it to stay running, However in Reverse, the only way I can get the stupid thing to back up is to continue switching the kill switch while giving it gas. What is wrong with this stupid thing?

I'm going crazy and I really need to use this thing, it's muddy here and I use it to move hay for my horses. HELP!!!!!!1