MCSB 95-11
Revised November 1997

Shift Spool for Alpha One & Alpha One Generation II

All Alpha One / Alpha One Generation II Standard and Counter Rotation Drives


The Alpha One Generation II counter rotation drive has been changed to allow the propeller to ratchet while in forward gear. The new style shift spool assembly (818349A1) is a dual acting shift spool that allows the propeller to ratchet upon deceleration while in forward gear like the standard rotation drive does. This eliminates the possibility of the engine stalling when the boat is rapidly decelerated to an idle speed without shifting into neutral.

The new shift spool assembly will be utilized in the following applications:
All Alpha One and Alpha One Generation II counter rotation service replacement drives.
All Alpha One and Alpha One Generation II counter rotation lower units complete.
The old style shift spool (19755A2) will supersede to the new (818349A1) shift spool.

                          19755A2                                818349Al

Where is the shift spool located?

Special note about shift spools.

Do Not confuse the spool described in the service bulletin  with the "spool" shown above. The picture on the right shows a gap but, that is because the spool shaft is worn or stretched and moves in and out. It is not supposed to have any end play on the shaft. Spool have No detectable end play on the spool shaft. If you see one of these in your unit, replace it. Do not adjust it like as suggested in the older service books. The spring inside could be collapsed and/or the shaft could be stretched and could break. This applies to both the old and new style shift spool/shaft assemblies.

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