Small Engine Disassembly - Notes
Day 1 (sections 1, 2, 3 & 4)
1. Check ignition timing
spark tester
• Be sure to disengage all kill switches
2. Drain fuel and oil
3. Remove air filter
funnel and oil pan
flat screwdriver
4. Remove linkages to carburetor
• Be sure to look at carburetor linkages to make sure you
know how to put it back together.
• Don’t use pliers to unhook linkages they are too fragile
• Leave linkages attached to the carburetor side
5. Remove kill switch wire
• Push up on the small brass tab
6. Remove carburetor and gasket
4-way screwdriver
• Put screws back into the gas tank
7. Remove gas tank
8. Remove throttle assembly
½” socket and nut driver
½” socket and ratchet
9. Remove muffler
7/16” socket , nut driver, punch and plastic
mallet
• On some engines you will need to bend the tabs back
10. Remove blower housing
3/8” socket and ratchet
• Remove oil fill and dipstick on some engines
¼” socket
and ratchet
11. Check compression
compression tester
• Turn flywheel clockwise and note resistance or use a
compression tester
12. Remove spark plug
spark plug socket and ratchet
Day 2 (sections 1, 2 & 3)
13. Check air gap
flat feeler gauge
• Rotate magneto until the magnets are across from the
armature (magnetron/solid state ignition)
14. Remove armature and governor
¼” socket and nut driver
• Rotate magnets away from armature
• Do not expose coil and armature to cleaning solvents
15. Remove cylinder head
½” socket and ratchet
• Try to keep the bolts in the same place/order
16. Remove cylinder head gasket
17. Remove valve chamber breather and gasket
¼” socket and
nut driver
18. Check valve-to-tappet clearance
flat feeler gauge
• To check valve clearance the piston needs to be ¼” down on
the power stroke
• Using the feeler gauge measure the distance between the
valve stem and the tappet
Ø Intake valve clearance should be .005 to .007
Ø Exhaust valve clearance should be .007 to .009
19. Remove valves large screwdriver or valve spring compressor
• Place screw driver underneath the edge of the valve spring
keeper.
• Raise the keeper with the screwdriver
• Push the keeper back towards the engine block
• Rotate flywheel and pull valves out
20. Remove valve springs and valve spring keepers
• Be sure to keep the valve springs and valve spring
keepers with the corresponding valve
• Always put the stronger/heavier spring on the exhaust
valve
21. Remove the flywheel
flywheel holder, 15/16” socket and
breaker bar, plastic mallet flywheel
puller and 7/16” open end wrench
• Hold the flywheel with the flywheel holder and use the
15/16” socket and breaker bar to loosen the flywheel nut
• Remove flywheel nut and starter cup
• Take the flywheel off the shaft
Ø Lift upon the flywheel and gently tap the end of the
crankshaft with a plastic mallet or piece of wood and
a hammer
or
Ø Use the proper flywheel puller
§ Thread the flywheel nut back onto the shaft
just so that the top of the shaft is just below
the surface of the nut
§ Thread flywheel puller (using the top nut/self
tapping screws) down into flywheel deeply
§ Turn nuts on the bottom of the puller down
and tighten them
§ Start applying pressure to the flywheel by
tightening the middle nut evenly on each side
§ Remove flywheel puller by loosening the
bottom nuts then the top nuts/self taping
screws
§ Remove large flywheel nut
§ Take the flywheel off the shaft
22. Remove and inspect flywheel key
• Don’t loose flywheel key
Day 3 (sections 1, 2,
23. Remove oil sump pan
3/8” socket, speed handle
emery cloth, and plastic mallet
• Place engine on it’s side
• Remove any burrs, rough spots and/or rust from crankshaft
with a emery cloth
• Remove oil sump pan bolts with a 3/8” socket and speed
ratchet
• Tap oil sump pan with a plastic mallet to remove oil sump
pan
24. Remove oil slinger
25. Remove camshaft
• Tappets should remain in the proper position before
removing the camshaft
• Be sure to notice how the groove in the camshaft
aligns with the dot on the crankshaft gear
• Remove camshaft by lifting it from the block
26. Remove tappets
tape
• Be sure to label the tappets with a piece of tape in
order to be able to replace them in their original place
27. Remove rod cap
5/16” socket and ratchet
• Loosen and remove rod cap bolts with a 5/16” socket and
ratchet
• Remove rod cap
• Note the position or alignment grooves when
removing the rod cap so you will know how to put it
back together
28. Remove piston
emery cloth
• Check for a ridge in the cylinder and remove it with a
emery cloth
• Turn the crankshaft to raise the piston to TDC
• Continue to rotate the crankshaft until it is free of the
connecting rod
• Reach your hand inside the engine to push the connecting
rod and piston up
• Lift the piston and connecting rod from the engine
• Be sure to notice the notch on the piston – it should be
pointing up on vertical shafted engines when
reinstalling
29. Remove the crankshaft
• Pull the crankshaft straight out
• Check the crankshaft for straightness by rotating on a
level stand, check magneto end in a drill press or place in
a lathe
30. Remove rings
• Be sure not to break rings
• Use your fingers to spread the rings and raise the
opposite side
• There is a small spring spreader below/behind the oil ring
31. Remove wrist pin
long nose pliers
• Remove snap/keeper ring using long nose pliers
• Use a punch and rubber mallet to drive wrist pin through
piston
• Be sure to drive it out through the end that the snap
ring was on
• Notice the metal tab on the connecting rod should
align with the notch on the top of the piston