Note:
When loosening/removing a screw, nut, or bolt, the turning direction is counter clockwise. Of course tightening is clockwise. There are no reverse thread fasteners on this engine.

1. Remove the muffler and gasket by removing the two nuts. Use a 12mm combination wrench or socket and ratchet.

2. Grab the hard plastic part of spark plug wire (socket) and pull it off. Never pull on the soft insulated part of the wire. You can damage the connection.

3. Use the 3/16” 3/8 drive socket and 3/8” drive ratchet to remove the spark plug.

4. Remove the air filter housing and filter by removing the two wing nuts. With it, the crankcase vent hose.

5. The fuel hose can be removed using your long nose pliers. Squeeze the tabs together on the clamp and slide it down the hose. Pull the hose off the carburetor.

6. To remove the carburetor, remove the two 6x1mm nuts and one 6x1mm 20mm bolt. Use the 10mm 1/4” drive socket and ratchet. Slide the carb intake manifold and gasket off the long 6x1mm studs. Do the same to remove the carb. There is also a plastic insulator and gaskets.

7. Remove the throttle lever by removing the 6x1mm nut. Use the 10mm socket and 1/4” drive ratchet. There is a spring washer and nylon washer as well. Disconnect the connecting rod and springs using the long nose pliers.

8. Remove the gas tank by removing the two 6x1mm nuts and one 6x1mm 20mm bolt. Use a 10mm wrench or socket. The fuel hose should come with it.

9. Remove the governor springs and connecting rod by loosening the 6x1mm 20mm bolt and nut. The connecting rod should slid off the shaft. BUT make note of the position of the rod on the shaft.

10. Remove the four 6x1mm 12mm bolts using your 10mm socket and ratchet to remove the pull starter. Remove the white plastic cooling fan.

11. Remove the engine stop oil alert unit by removing the 6x1mm nut. Disconnect the two wires. Disconnect the oil level switch feedthrough nut. Use your 14mm combination wrench.

12. Measure the gap between the magneto and flywheel using a feeler gauge. Remove the magneto along with the spark plug wire by removing the two 6x1mm 25mm bolts. Use your 10mm socket and ratchet.

13. Remove one 6x1mm 20mm bolt and one 6x1mm 12mm bolt using your 10mm socket and ratchet to remove the throttle control base.

14. Remove the 14x1.5mm starter pulley nut. Use your 3/4" 3/8” drive socket and ratchet. You will also need a strap wrench to hold the flywheel. There should be one floating around the lab. Ask your TAs to help you.

15. Remove the flywheel shroud by removing one 6x1mm 20mm bolt.

16. To remove the flywheel and key you will need to use a “wheel puller”. There should be one floating around the lab. Ask your TAs for help.

17. Remove the valve cover and gasket by removing four 6x1mm 14mm bolts. Be careful not to damage the cork gasket.

18. Remove the heat shroud by removing the two 6x1mm 14mm bolts.

19. Remove the head by removing the four 8x1.25mm 55mm bolts. Use your 12mm 1/4" drive socket, 3” extension and 1/4" drive ratchet. The valve push rods will come out as well.

20. For the crankcase cover, make sure the long rectangular key is removed from the keyway. Remove the cover by removing seven 6x1mm 30mm bolts. Use your 10mm socket and ratchet or combination wrench. The cover slides off the crankshaft, which extends through the crank bearing.

21. Note the position of the camshaft gear and crankshaft gear. There is a small indentation on the crank gear and two larger indentations on the cam gear. These must line up when reassembling. Remove the camshaft and the two cam lifters.

22. Remove the oil level switch. By removing the two 10x1.25mm 12mm bolts.

23. Remove the piston by removing the two 7x1mm 40mm bolts on the connecting rod.

24. Remove the crankshaft by sliding it out of the crankshaft bearing.

Notes: Insert the crankshaft first.
Use the piston tool (a cylinder with adjustable diameter) to squeeze the piston rings to the correct diameter and insert the piston. (Ask AI for assistance)

Complete the disassembly instructions in reverse with the exception of step 20, installing the crankcase cover (you may want to save this step until you have finished most of the maneuvers with the engine).