Kirbysthebest
Harley,
Not all of them do, and of course the impeller fans you mention are not all the same (other than them all having, as you mentioned, nine blades except for the one used on the pre-1976 machines) due to varying shaft hole sizes on them, although it is possible to change out the internals of a weaker motor group to those of a stronger one (e.g. from 3 amp to 6 amp), making sure you know what all the parts to that version of the motor assembly is. Here's a rundown:
Pre-1976 machines use impeller fan number 1-053004-000 with armature 1-602001-000, field 1-801002-000 and driveshaft 1-285261-000. This impeller fan has a 7/32" (0.22") diameter shaft hole size.
1976-89 machines use fan number 1-608004-000 (screw on type) with armature 1-608001-000 (3 amp) or 1-880001-000 (4.5 amp), field 1-801002-000 (3 amp) or 1-880002-000 (4.5 amp) and driveshaft 1-608261-000. This impeller fan has a 1/4" (0.25") diameter shaft hole size.
1984-90 machines use fan number 1-620004-000 (screw on type) with armature 1-618001-000 (5.4 amp) or 1-620001-000 (6 amp), field 1-618002-000 and driveshaft 1-618261-000. This impeller fan has a 5/16" (0.31") diameter shaft hole size.
1990-95 machines use fan number 1-608005-000 (slip on type) with armature 1-884001-000 (5.4 amp), 1-680001-000 (6 amp) or 1-780001-000 (7 amp), field 1-618002-000 (5.4 and 6 amp) or 1-780002-000 (7 amp) and driveshaft 1-380261-000. This fan, like the 1-620004-000 impeller fan, has a 5/16" (0.31") diameter shaft hole size.
The 886 was produced from 1987-95. It would be light blue in color if it was made before 1991. Pre-1990 machines used the 1-620004-000 impeller fan with the 1-620001-000 armature, 1-618002-000 field and the 1-618261-000 driveshaft. 1990-95 machines took the 1-608005-000 impeller fan with the 1-680001-000 armature, the 1-618002-000 field and the 1-380261-000 driveshaft.
Its predecessor, the 880, could be had with the many different motor internal groups mentioned over the years. Again, the list of what was used is listed below:
Before 1976 (these machines also had a front bearing):
1-602001-000 Armature
1-801002-000 Field
1-053004-000 Fan (0.22" shaft hole size)
1-285261-000 Driveshaft
1976-1980:
1-608001-000 Armature
1-801002-000 Field
1-608004-000 Fan (0.25" shaft hole size)
1-608261-000 Driveshaft
1980-1985:
1-880001-000 Armature
1-880002-000 Field
1-608004-000 Fan (0.25" shaft hole size)
1-608261-000 Driveshaft
1985-1987:
1-618001-000 Armature
1-618002-000 Field
1-620004-000 Fan (0.31" shaft hole size)
1-618261-000 Driveshaft
When finding either a 1-608004-000 or 1-620004-000 impeller fan today, it will (like you just said) have nine blades like the current impeller fan (1-608005-000).
~Ben