Clean The Motor

• 1). Remove the entire engine fixture from the chassis; it's best to spray everything down with the motor cleaner/ degreaser before opening it up.
  
  
• 2). Remove the air filter and submerse the entire engine in a sink of hot, soapy water. Separate the components to ensure a thorough cleaning. Use the bottle of compressed air to dry small crevices; once everything is dry, apply air filter oil to the filter, squeezing it so that it is completely covered. Reassemble the air filter fixture and set it aside.
  
  
• 3). Remove the flywheel collet by prying it off. Unscrew the carburetor and the starter back plate. Pry off the plate and remove the starter shaft.
  
  
• 4). Rotate the crankshaft until the piston is at the 6 o'clock position, or bottom dead center. Remove the screws in the cooling head and detach it from the engine.
  
  
• 5). Pull out the piston sleeve with your finger (or a pen if it's a tight fit). Tap your hand on the side of the engine to knock the piston off the crank; slip it out by hand or with a pair of needle-nose pliers. Point the crank shaft down, and press it firmly to pop it loose; remove the crank shaft from the engine.
  
  

Clean It Up

• 1). Lay out all of the parts, and spray everything down with the cleaner/degreaser, including inside the engine block. Allow everything to dry completely before reassembly.
  
  
• 2). Insert the crankshaft and rotate it to make sure the bearings are running smoothly. Replace the piston so that the conrod (the hole in the piston) is facing in the right direction. Seat the conrod back onto the crankshaft using the tip of the screwdriver. Twist the crankshaft to test that everything is properly connected.
  
  
• 3). Rotate the piston to the 12 o'clock position (top dead center); holding the engine upside down, line up the notch on the sleeve with the notch in the crank case. Use a pen to align the piston as you push the sleeve back into place. Test that everything can rotate freely.
  
  
• 4). Replace the cooling head and push the starter shaft back through the faceplate; apply some high-temperature RTV sealant before tightening it back to the engine.
  
  
• 5). Screw the carburetor back into place.