Small Engines (Lawn Mowers, etc.): lawn chief 300, bad spring, lawn chief

Question
I bought a used Lawn Chief 300. The drive belt keeps coming off when I engage the clutch to shift. The belt doesn't appear that bad. Would changing the belt solve this? What other issue may cause this?

Answer
It could be the belt.  It could also be the idler mechanism or one of the belt retainers.  Often the idler is rusted some and won't move quick enough or gets stuck.  Usually a couple of shots of PB Blaster will loosen it up if this is the problem.  It could also be that there's not enough tension due to a bad spring.

This is one of those things that you just have to look at everything to find the problem, but one of the above will probably be it.