There are actually two different gm starters, the earlier standard hd marine starter and the newer
gear reduction starter. Its easy to tell the difference, on the gear reduction starter the solenoid and
motor are both about the same size. The earlier style starter the motor is quite a bit larger than the
solenoid. Both style starters are in use today. Either one of these starters come in clockwise and
counter clockwise rotation. The nose cone on these starters very as well such as in a diagonal or cross
bolt pattern or maybe from a top mount or lower mount location on the engine. The starter that will be
covered will be an earlier style of starter. These starters can be found in Mercruiser, OMC, Crusader,
Volvo and many other marine engines.
We will start with a starter that was removed from a boat and in a non working condition. As with this
starter most marine starters usually quit working because of living in a blige of a boat and end up
getting submerged numerous times. Rarely does the starter quit functioning because it is actually worn
First thing to do is to remove the solenoid by removing the retaining bolt for the electrical contact as
well as the two bolts that attach the solenoid to the starter. Then rotate the solenoid to release it
from the starter it is spring loaded so be careful. Once removed discard the solenoid and spring, but
keep the bolts for reassembly. Also remove the two bolts at the back of the starter holding on the end
cap. Arrows in the picture indicate the bolts to be removed.
Go ahead and pull the rear cover and casing apart. This starter is in pretty rough condition, but
salvageable. You can see in the picture where arrow is pointing a part of a broken spring from the brush
holder. The two smaller arrows point to two bolts that need to be removed to be able to pull out the
armature and flame shield from the nose cone. This shield is what determines this as a marine starter
rather than an automotive. Be careful not to loose the leather washer on the end of the armature.
The case has been cleaned here. The use of scrapers, wire brush, sandpaper, and solvent did wonders. I
removed the pins that held the brush holders and springs. I also removed the brushes for replacement
with new. The brushes were really not that bad but the corrosion was so bad I had to remove them anyway. Also I
had to add an extra brush spring from another parts starter because of the broken spring. Note
disassembly procedure of brushes so you can put the assembly back together correctly.