MD7A Starter Removal

[ckreitlein]

Here is how to remove the starter on an MD7A on a Cape Dory 30 Cutter. In this configuration, the engine is mounted backwards with the flywheel on the front of the engine facing the stern of the boat.

Tools needed:
1/2 drive socket set with up to 19mm or 3/4" socket
19mm open end wrench
17mm open end wrench
cheap 19mm box end wrench (Harbor Freight has a set of metric wrenchs for $9)
nut driver set 8mm and 10mm
screw driver
hand sledge
penetrating fluid
trouble light
angle grinder
rubber mallet

All wrench work is done from inside the cabin, on your knees, reaching back and over the engine. This description assumes neither alternator or starter have ever been removed. If they have been removed before, job should be much easier.

- Disconnect the batteries to cut all power to alternator and starter
- Remove air filter/muffler by loosing band screw and manifold hose.
- Take photos or draw wiring diagram for alternator wiring and starter wiring
- Disconnect alternator and starter wiring with nut driver set 10mm and 8mm
- Remove alternator
.... spray bolts and nuts with penetrating fluid and let sit
.....loosen bottom 17mm bolt with socket set. May need to tap socket wrench with sledge hammer to loosen bolt.
.....loosen and remove top 17mm nut with socket set. May need to tap with sledge hammer to loosen nut. Remove bolt.
..... loosen alternator top arching bracket with socket set and swing upward.
..... remove fan belt by pushing alternator toward engine, rotating on bottom bolt.
..... remove lower bolt while holding alternator and lift it out.
.... remove lower alternator support bracket with 17mm socket wrench

You are now ready to attack the starter removal. Starter is secured by two bolts/nuts - upper and lower. Upper bolt is very difficult to access. Bolt head is obstructed by gears of fly wheel and cannot be removed without removing the fly wheel. It is just accessible enough to put an open end 3/4" or 19mm open end wrench on it to hold it while the nut is removed. The upper bolt protrudes against the starter making removal of the nut difficult. The is little turning radius available to remove the nut, requiring turns of only 1/8th of a turn each time. The nuts on both upper and lower have nylon inserts which make the job that much more difficult.

- Spray everything with penetrating fluid and let sit overnight. Tap with small hammer to enable penetrating fluid maximum penetration.
- Take a cheap 19mm box end wrench and, using the angle grinder, grind down the thickness of the box end until it will fit between the body of the starter and the end of the top bolt. Do not grind off any more than necessary! Even after you grind down the thickness and see that it will fit you may find that as you remove the nut, the body of the nut prevents you from removing the wrench. If this happens, tighten the nut enough to remove the wrench and grind it down further.
- Remove the bottom nut first
.....using the 1/2 drive socket wrench and 19mm socket loosen the bottom bolt head. A socket will not fit on the nut, so try loosing the bolt head instead. With the socket wrench secure on the bolt head, tap with the sledge hammer. Keep the socket secure on the bolt head to not "round it off." Reaching over the engine to do this does not allow the leverage necessary to loosen the bolt by hand strength alone which is why the hand sledge is necessary. If the bolt turns, put a 19mm wrench on the head and attack the nut with a second 19mm wrench to remove the nut. If the bolt head will not turn, put a long 19mm box end wrench on the nut and tap that with the sledge. Once the nut is loose, remove it, but leave the bolt in to support the starter.
-Remove the top nut
.... put the ground down box end 19mm wrench on the top nut and using the sledge, tap it until it moves.
.... put a 19mm open end wrench on the bolt head to secure it from turning. This may take some effort to get the wrench on the bolt head because of the lack of clearance with the fly wheel gears.
Once it is on the bolt head, use the box end wrench on the nut to turn the nut off the bolt. Clearance will only allow 1/8th a turn, so this will take a while. Bolt does not have to be removed, so leave it... you cannot take it out anyway.
- Once the top nut is removed, use the rubber mallet to tap on the body of the starter to unjam it and knock it loose from its mounting ring. Lift it out. Remove the lower bolt for inspection. You are done removing the starter.
- All of this requires reaching up and over the engine and considerable contortions of the arms, but can be done.

With starter removed, clean up around the engine ground wire and bolt located below the starter. Test the connectivity of the engine ground wire with an ohm meter - one lead on the ground wire and the other on the engine somewhere.