My Gravely Pro 40 w/b has a problem. The 12.5 hp kaw. has to be replaced. Gas went through the carb. into the crank case and destroyed the main bearing (caused from trailering). Cost very little to get parts (few $100) but labor will bring it to $450. Now I'm swaping a 14 hp kaw for a new 17 hp kaw. on one mower (GD Scamper) and putting the 14 hp kaw on my Pro 40. Oh ya, this Pro 40 is just a cheap back up mower, that is going to come to a total of $1600 after everything is done. Turn off those fuel lines, and watch thoes carbs.