The engine runs great when not under load. When I put the tractor in gear either foward or reverse and let out the clutch pedal the tractor dies. Push it back in and the tractor runs. Also engaging the blades will also cause the engine to die. I have checked all fuses, the dead man swithc on the seat removed and cleaned all connections in the electrial system. cleaned the air filters, and replaced the fuel filters. My electrial schematic is pretty useless. Need some help here if you would. Im pretty handy (or so I thought) I cant seem to find anything on line that can give me a clue. The engine is a briggs and straton 21HP OHV Vtwin 6 forward speeds 42 inch cut.

Mike Matthews, January 2008

I recently had that problem.
I have the exact same model.
I discovered that there was pieces of newspaper where the spark plugs are.
Maybe an animal trying to make a nest there.
I removed it and there we go.

Marco Menendez, August 2009

Look down where the shifter is see if there is a spring hanging loose. That is the spring for the brake. It needs to be reattached, you will see where it attaches. It happened to me, and once it was attached it was fine.

kikubut, July 2008

You have a bad safety switch somewhere .....there is one for the deck too ....seat switch and 2 others I believe

bg, January 2008