Kohler PA-CH255-3021 Engine 3/4" x 2.42" Crank Horizontal Shaft Electric Start 5.5 HPKohler PA CH255 3021 Engine 3 4" x 2. 42" Crank Horizontal Shaft Electric Start 5. 5 HP This is what it takes to be a PRO. Performance driven features like a heavy duty air cleaner, forged steel crankshaft, electronic ignition and cast iron cylinder liner. KOHLER Command PRO is the standard for professional grade power and performance. Features: Quad Clean all season four stage cyclonic air filter effective engine protection for tough and dirty