Removal/Overhaul of GL1200 starter motor.
I have attempted to make this list of instructions as simple as possible so
that it could be understood by all. Should you have any questions or need
clarification with respect to any aspect of this procedure, please do not
hesitate to contact me via email at firstname.lastname@example.org
To understand why the bike must be on the sidestand for this procedure,
you must understand that the starter is driven by a gear in a drive chain
off the starter clutch. The starter is plugged into the engine casing and
engages the gear that basically hangs loose in the chain that comes down
from the starter clutch. After you pull out the starter, you will notice
the round hole. When you look into the hole, you will see the gear hanging
in the chain in the middle of the open hole. If the bike was on the
centerstand, the chain would swing over and the gear would not be in the
middle of the hole. Thusly, the starter will not engage the gear when you
go to plug it back into the engine casing. Put the bike on the sidestand
and leave it there until the starter motor is back in.
**** This removal procedure applies to the 1985 (late) to 1987 GL1200 only.
The 1984 and early 1985 GL1200 starter motor is different and can be removed
by following the instructions given for the GL1000/1100 series. The late 1985 to
1987 starter motor is easily identified by the hump on the casing near the
reduction gear case housing where it plugs into the engine.
1. Bike on sidestand.
2. Disconnect the battery.
3. Disconnect the cable from the starter motor.
4. If the bike is equipped with floorboards, remove the one on the starter
side as well as the heel/toe shifter and any connection to the shift shaft
protruding from the engine.
5. If the bike is equipped with a factory shifter, remove it from the shift
shaft as well as the footpeg.
6. Remove the exhaust system on both sides of the bike and just lower it to
the ground. This sounds involved but is actually quite easy. There are
4 exhaust nuts per side and the rear hanger bolts. You will need new
copper exhaust gaskets for the reinstallation.
7. Remove the two exhaust manifold studs from the bottom of Cylinder #4
(the rear one on the left side). Use a stud remover tool or the old
double nut trick.
8. Remove the two 8mm bolts that secure the starter motor to the engine.
Wiggle the starter out of the engine casing and away out through the
area that you created by removing the exhaust and studs.
9. Repair the starter motor as required.
10. Reinstall in the reverse order. Put grease or vaseline on the O ring
to aid in inserting the starter back into the casing.
The starter motor itself consists of three (3) main sections. Prior to
disassembly, use a scribe or felt marker and mark the casing across the
three sections to ensure that they are reassembled correctly and are
oriented to each other.
1. remove the three long bolts that hold the sections together and separate
them. Be careful as there are a series of flat thrust washers on each
end of the armature (located in the middle section). Record the
location and number of the thrust washers. Ensure they go back in their
original locations upon reassembly.
2. the end cap basically performs no function other than to cover the brush
plate and commutator area as well as center the armature shaft with its
bearing in the end of the cap.
3. the drive end contains the reduction gearing and if need be, can be
disassembled to replace the bearing. This is extremely unlikely. The
shaft should turn freely and normally only requires a cleaning and
grease application. Simply remove the gear case cover screws, inspect
the gears for wear or damage (not likely) and lubricate the gears with
grease. Align the dowel pin with the groove on the gear upon reassembly
of the gear case.
4. remove the brush plate from the end of the center section by removing
the screw at the one brush connection. Before removing the brushes,
note that one of them has an insulating sleeve over the braided wire.
The replacement must go in the same brush holder. Remove the brushes
and replace if necessary and clean the brush plate. ** Brake Cleaner is
a good general cleaner for this entire job.
5. remove the armature from the center section.
6. thoroughly clean everything using the Brake Cleaner. Although the
cleaner will dry without leaving a film, it is suggested that the
components be dried with compressed air.
7. get some extremely fine steel wool (000 of even 0000 is better) and
gently clean the metal surfaces or bars of the armature and the
commutator. Blow with compressed air.
8. using a volt/ohmeter, test for continuity between pairs of armature
bars (the long ones). There should be continuity between the pairs
around the entire circumference.
9. check for continuity between pairs of commutator bars (the short ones),
and also between the commutator bars and the armature shaft. There
should be continuity between the pairs of bars but NOT to the shaft.
10. check for continuity of the field coils. There should be from one end
to the other.
11. check for continuity from the cable terminal to the motor case and from
the cable terminal to the brush wire that protrudes at the other end.
There should be continuity from the terminal to the brush wire but NOT
from the terminal to the casing.
12. reinsert the armature back into the center section.
13. reinstall the drive end with the reduction gears.
14. reinstall the brush plate with the new brushes.
15. reinstall the end cap.
16. reinstall the three long bolts.
Test the starter by hooking jumper cables up - positive lead to the cable
connector and negative lead to the starter motor casing. The starter should
dance across the table or floor.
*** the modification made to the grounding circuit of the starter motor is
not really necessary, but if you wish to provide a more precise ground
connection, then an appropriate section of stranded copper wire will have
to be spot welded (preferably) to the brush plate with the other end
secured to the end cap via a simple nut and bolt mounted in a drilled
through hole in the cap. I suggest you seal the hole with silicone to
waterproof the area. Rather than spot welding, the end could be riveted
securely to the brush plate. Take your pick.