Engine Skill-a-Thon Group members______

1.  Checking the armature gap

·  Use a feeler gauge to check the distance between the armature and the rim of the flywheel. Move the magnet away from the armature to do this.

·  Check the operator’s manual. What is the armature gap suppose to be.

2.  Checking spark plug

·  Check the spark plug gap on the spark plug.

·  What is the measurement?

·  Identify the parts of the spark plug.

3.  Piston Rings

·  Check the owner’s manual to find the following:

o  Piston ring end gap

o  Piston ring side clearance

4.  Checking Piston displacement

·  Measure the distance from the top of the cylinder to the top of the piston at BDC

·  Measure the distance from the top of the cylinder to the top of the piston at TBC

·  Subtract TDC from BDC. (stroke)

·  Measure the Bore.

·  Use the formula: Bore2/4 x π x stroke to find piston displacement for this engine.

5.  Torque the cylinder head bolts

·  It is important to torque all bolts to the proper specifications. Look in the owner’s manual for the specifications.

·  What is the order (pattern) that you should use to torque the head bolts? Draw it here.

·  What should the bolts be torqued at?

·  To torque the bolts, go half way to the torque number, then go to the next bolt in the order. Do the whole pattern, then do the pattern again, torquing it the rest of the way. DO NOT torque one down the whole way. You will wreck the gaskets.

·  Loosen up the bolts for the next group.

6.  Tappet Clearance

·  Set the piston to TDC and use a feeler gage measure the gap between the valve stem and the tappets.

7.  Identify the parts of the carburetor

  1. ______
  2. ______
  3. ______
  4. ______
  5. ______
  6. ______
  7. ______
  8. ______

Fuel bowl cover

Fuel cover screws

Fuel bowl cover gasket

Main carb body

Carburetor bolts

Inlet needle

Float