Craftsman 18hp riding mower stalls when engaging the blades. Model 917-255917?
I would think that you have a lean fuel mixture. You probably can't adjust the main jet so the next guess would be that the carburetor needs cleaning. You might try some in the tank fuel system cleaner but don't be disappointed if it doesn't work. Try moving the throttle to partial choke when engaging. Old gas will make it run bad also.
