Crankshaft And Bearing Replacement - Boss 36 BHP PISTON Service And Maintenance User Manual

VIII. Place the pump cover into position and start two bolts (bolts must be diagonally opposed). Strike
the pump cover with a rubber faced mallet to jar the pump loose. When the tension spring can be
felt against the pump cover, the pump is loose.
IX. Insert the two remaining bolts and torque to 180 in-lbs. The bolts should be torqued in a diagonal
pattern.
X. Install the air compressor in the vehicle. Connect the air lines and wiring.

3. Crankshaft and Bearing Replacement

If it is necessary to replace the crankshaft, related components must also be replaced. Replace both
bearings, both races, the key, pump collar and pump drive pin.
I. Shut down machine and allow to cool for approximately 10 minutes.
II. Verify entire system pressure is relieved before proceeding.
III. Remove both heads, cylinders, and pistons. See Piston Ring Replacement on P. 21.
IV. Remove the bolts on the connecting rods, and lift them out. Reassemble the connecting rods to be
certain that the matched parts remain together on the same crankshaft journals.
V. Remove the pump cover, oil pump, sleeve, spring, and rear bearing housing.
VI. Remove the drive hub, and the front bearing housing.
VII. Pull the crankshaft from the crankcase.
VIII. Remove all gasket material with a single edged razor blade, or sharp putty knife.
IX. Press the bearing races out of the bearing housing.
Maintenance
Depending on the condition of the crankshaft, bearing may be replaced
without replacing the crankshaft. Replace the bearing races whenever the
bearings are replaced.
Do not allow the gasket material to fall into the crankcase. Do not nick
the head, cylinder, or crankcase mating faces while removing the old
gasket. Remove all of the old gasket material to provide a smooth,
clean surface for the new gasket. Failure to follow this procedure may
result in the need to reseal the unit later.
Do not gouge the machined surfaces when removing the gaskets. This may
cause leaks.
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