Lawn Mower fouls Plug in 5 minutes?

Also sounds like carb. to me. but do you have blue or black smoke. If blue you have a oil problem if black then fuel. The complete carb. for this mower is PN 790206 or substitute no. 795475 and is 28.00 plus shipping from sears. If you want to try and replace the diaphragm and clean the old carb. The diaphragm is 3.00 from sears plus shipping. To check on all parts for the mower go to sears.com then the parts store. Type in model no. and go from there.