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14.2 REPLACING A CRANK/CRANK BEARING
Replacing a crank bearing is necessary when it is fractured or when the nuts of the big-end
regularly become loose. The crank bearings, the crank bearing fittings or the big-end pin
holes in the crank are damaged. Replace the crank / the bearing as soon as possible in
order to avoid any further damage to other parts, as follows (see fig 13):
1. Remove the bolts and nuts (7 & 8) of the actuating rod's connecting strips (9).
2. Remove one or both of the actuating rod’s connecting strips (9).
3. Remove the big-end nut (11) and big-end pen (10).
4. Remove the big-end (4).
5. Remove the bolts and nuts (5 & 6) and closing plates (1).
6. Take out the crank (3).
7. Remove the bearing (2).
8. Replace the defective parts and reassemble in reverse order.
Use Loctite for nuts 1 and 3.
14.3 RELIEVING CRANKSHAFT TENSION
When components of the crankshaft have been replaced, the crankshaft might run with
more resistance. The cause could be pretension. It is necessary to remedy this tension as
follows:
1. Check which big-end runs with more resistance and causes tension.
2. Use a hammer to hit the cranks in question, next to the big-end causing tension, in
order to remove the tension.
3. Check each big-end of the crankshaft for tension until the tension is removed from all
the elements.
In order to prevent damage to the crankshaft, do not use the machine before all
the tension is removed from the crankshaft.
After repair of the crankshaft, nuts should be regularly checked for looseness.
Mount the cranks in the correct manner; see the parts page for the correct sequence and
parts numbers.
