!750/2000 Starter Identification and Rebuild

[Kevin Trent <trentkc@domain.elided>]

The starter in my berlina with a '69 1750 engine was giving me an
intermittent failure by just doing nothing.  No click from the solenoid or
draw on the battery.  Fred Di Matteo diagnosed the problem as worn brushes
in the starter that were preventing the solenoid circuit from engaging
because the circuit was through the brushes to ground.

This weekend I'm going to "service" the 1750 starter, as well as a spare
starter from my pile o' parts which (I think) came from a 73 2000 engine
when I replaced it with (I think) a '71 1750 starter.

First question:  Are these starters interchangeable?    Below are the
numbers from each:

1750 number on body of motor (in 3 rows): 222; BOSCH, 0 001 211 025
1750 number on mounting flange: 2 005 822

2000 number on body of motor (in 3 rows): 322; BOSCH, 0 001 211 987
2000 number on mounting flange: 1 005 822

Both starters have 9 tooth pinion gears, have the same dimensions, are
.7ps, and use the same solenoid :  Bosch (in 3 rows): 0331; 302064; -564

Question 2:  Both starters use the same size brushes, the  2000 brushes
worn to a length of 14mm, and the 1750 worn to 16mm.  Are these lengths in
spec?  How long are new brushes?
BTW, the 1750 starter's commutator is very dirty, and the brushes show
evidence of past replacement.

Question 3:  Any advice on the "servicing" of these starters?   I ran both
on the bench before removing the brush cover, and the solenoids engage and
the motors spin up well.  I'm leaning to just servicing the brushgear only.
 I was going to polish up the commutators with emory cloth (what grit?),
then clean the gaps in the insulation between the segments.  I can stop
there, and just relube and reassemble without removing the  solenoids or
the pinion/clutch.  Is there any value in taking them all apart for
cleaning?    Every time I do something like that, it seems like I'm just
asking for trouble... 

Thanks,  ///  KCT, Powell,  Tennessee

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