Shifting Difficulties

There are occasions when it is necessary to remove the shift mechanism from the engine.  Those with a left side shift can generally be removed entirely while those with the shift on the right will require the separation of the center cases to remove the shaft.  A snap ring inside the left case half retains the right side shift shaft.

The shift plate assembly can be removed in either case inside the primary after removal of the primary cover.  When disassembly is necessary due to worn parts or curiosity you will find it assembled in a logical sequence in this order:

1. Two 5 x 25 mm bolts
2. One locking plate
3. One cover plate #0266.101
4. One spring #0266.014
5. One fitting #0266.105
6. One plate #0266.102C with #0266.103 pin inserted or shaft 2166.118.
7. One plate #0266.013 or #4366.013, four or five speed respectively for the right side shift models. Etc.

What this is leading up to is the shaft with #0266.005, #3466.005, and #2166.005 for the right side shift models and #2166.036 for the left side models.  When you look at the end of this shaft you will note that it has a long slot across its face containing a light spring and engagement pawls.  You think it is centered.  It isn’t.  It’s slightly off center.  The shaft when placed upside down will give you; at the most, two gears.  Rotate it 180 degrees and reassemble.  This should bring all of your gears back.

The slot should be off center above center.  This will not be horizontal but turned a bit clockwise.  The plate suffix ….012, called a gear, with the pawl engagement notches must be placed correctly.  This plate will have the number of shifts available pressed into the front of the plate, these being 4, 5, or 6.

Another problem can occur with a damaged pawl spring.  If it has become weakened or bent it cannot provide adequate spring pressure to press the pawls into engagement.  It will need to be replaced.  Restretching it or rebending it won’t provide adequate tension.  The spring is an inexpensive item costing less than $2.00.  This is an extremely rare occurrence but it happens.

The service information advises you after the engine cases are closed to work the gears by hand to see that selection of all gears occur.  Use the shift lever on the splines and not a pair of pliers to rotate the shaft.  Pliers will damage the splines.  The detent plunger on the shift drum should be installed.  The hex head cam that is fastened with a 6mm nut and lock washer to a 6mm case stud should center the stop plate for the initial adjustment.  This adjustment is for firmly engaging the first and top gear.  Engage first gear.  Check to see if it is fully engaged.  Adjust if necessary.  Manually work through the gears until top gear is engaged.   If it is not fully engaged go back to first gear.  Readjust the cam.  Relock the cam and try again.  All of the intermediate gears should readily engage.   If you think to scribe a mark with a metal scribe on the cam to a reference point on the engine case this adjustment may not be necessary for future assemblies.

If the pawls are excessively worn they should be replaced.  You might have noticed that they do not engage along the full width wedge surface.  You may get by with installing them the other way around.  Damaged shift pawls do not allow a smooth engagement when shifting gears.  Missing gears is best suffered by other manufactures machines.

Check for bent shift shafts.  The shaft will drag against the cover and not return smoothly or at all.  This is more common to the right side shift models.  The only good way to fix this is by replacement.  Straightening the shaft is difficult.  On right side shift models it is nearly impossible.

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