Chapter 10 Crankshafts, Camshafts And Lubrication; Crankshafts; Crankshaft Timing Mark; Camshaft Removal - Tecumseh VLV Technician's Handbook

Crankshafts

Do not attempt to straighten a
CAUTION
bent crankshaft. Doing so will
damage gears, and result in engine failure.
Inspect crankshaft for worn, scratched or damaged
bearing surfaces, out-of-round or flat spots on the
journal area, or a bent P.T.O. end.
When
CAUTION
lubricate all bearing surfaces
prior to assembly. Leaving these parts dry could
accelerate wear at start-up.
When installing a crankshaft, lubricate all bearing surfaces
and use oil seal protector part no. 670327.

Crankshaft Timing Mark

The crankshaft has a pressed-on timing gear. This gear
has a small dimple punched on one of the teeth on this
gear.
This dimple is a timing mark. With the crankpin at top
dead center, the timing mark should be in the 2:30
position.
NOTE
Timing marks on crankshaft gear and camshaft gear must
be aligned for proper valve timing.
10-1
Chapter 10
Crankshafts, Camshafts and Lubrication
servicing crankshaft,
2:30

Camshaft Removal

Align timing marks to relieve valve train pressure. Lift
out cam.
The camshaft has a mechanical compression release
mechanism. A pin which runs through both cam lobes
extends past the exhaust lobe and lifts the valve to relieve
compression for easier starting. When the engine starts,
centrifugal force moves the flyweight outward, moving the
pin below the lobe, allowing full compression.
NOTES
The compression release mechanism is nonserviceable.
Replace camshaft assembly if damaged or worn.
The camshaft has been relieved in the intake lobe area.
This change was made to accommodate added crankshaft
counterweight material for improved engine balance.
Compression Release
Mechanism
Crankshaft
Counterweight
Relief
695578