Here are some forums that may be of assistance to you:

The Best Snowblower & Lawnmower Forum: www.opeonthenet.com (I'm one of the moderators at this one)

Precise Engine Repair: www.perr.com/forum/ (a wealth of repair experience here, GREAT guys!)

Gardening, OPE & MUCH more: www.gardenweb.com (peruse around - very informative!)

Cub Cadet Tractors: www.ihcubcadet.com (VERY hard core Cub fans, nice guys but a bit "clicky")

John Deere Tractors: www.weekendfreedommachines.com