Small Engines (Lawn Mowers, etc.): Craftsman 6.75hp model 917.378420, drive mechanisms, drive wheels

Question
I have a Craftsman 6.75hp 21" Mutli-Cut Front Propoelled Lawnmower model 917.378420. It's not moving forward anymore. I have to push it. Is it any belt needs to be replaced in that or there is something else? Unfortunately I don't have the Owners' manual for it.

Thanks for your help.
Mark

Answer
Not sure about your particular model but the drive mechanisms are fairly simple to diagnose.  You will need to remove any shrouds, etc. between the engine and the drive axle.  You need to then determine where the break in power transfer between the engine and the drive wheels is occurring.  If you contact Sears, they should be able to get you some service information specific to your mower.  Hope this helps.