Remove the throttle control clamp screws on the lawnmower handle using the appropriate screwdriver. Turn the screws counterclockwise.
Measure the distance from the top of the mower handle down on either side to the handle mount brackets on the frame of the mower using a measuring tape. Mark the center between the two points on the handle using a metal scribe.
Measure 3 inches up from the center mark on either side of the handle and scribe a line across the surface.
Cut each side of the handle at the 3-inch mark using a tubing cutter and remove the severed upper section.
Position the upper section on a hard surface. Have a helper hold the section upright on one side, maintaining the position using a level.
Set a 1/2-by-3-inch bolt on the top of the handle tubing that is on the surface. Place the head of the bolt against the open end of the tubing. Strike the bolt with the hammer to create an indent in the tubing.
Repeat Steps 5 and 6 on the opposite side of the handle.
Install the indented upper section over the handle’s lower section. Clamp the sections together using vise-grip pliers.
Drill a 1/4-inch hole on each side of the handle approximately 1-1/2 inches up from the end of the indented tubing. Use a drill with a 1/4-inch steel drill bit.
Install a 1/4-by-1 1/4-inch bolt through each side of the handle followed by a 3/16 lock washer and a wing nut. Tighten the wing nuts clockwise by hand.
Remove the vise-grip pliers from each side of the handle.
Replace the throttle control onto the handle and tighten the clamp screws clockwise with a screwdriver.