Topic: Alternator Cover Replacement Procedure

[Vintageguy]

Have a 1978 750F. Want to replace the alternator cover. What is a step by step instruction for this? Do I need to remove the cover behind the alternator cover in order to unplug the alternator? I assume this is where it plugs in, but not entirely sure. Do I even need to unplug it in order to change out the cover. Thanks for any/all responses.

[BenelliSEI]

Does your replacement cover have the “coil” (see photo) already fitted inside? If it does, you just unplug all the wires and swap it over. The harness they attach to does pass through, under the transmission side cover. I usually take it all off for this swap. Good time to give them both a good scrub and change the seal on the shifter shaft.

[BenelliSEI]

If your replacement cover is empty, and you plan on swapping the insides over, take  both covers off. You’ll also find the wires to the neutral switch and low oil pressure switch in there too. You will need a hand held impact driver, for sure. Before you remove the covers, knock the three centre screws (around the HONDA badge) loose. They hold the central, fixed spool in place and are easier to loosen on the bike.

If you are in no rush, watch my 1976 Honda cb750 Project posts. I have to pull both those covers and strip them down, before getting them polished by a local guy. I’ll take a few extra photos and show the step by step, if you want? Let me know.

P.S. I usually replace the section of wire harness that attaches these components to the main harness. You’ll find the original very brittle and stiff. The insulation and outer cover often falls apart when you disturb it. These are cheap at $15-20.

[Don R]

 Good idea ^ !

[HondaMan]

If your replacement cover is empty, and you plan on swapping the insides over, take  both covers off. You’ll also find the wires to the neutral switch and low oil pressure switch in there too. You will need a hand held impact driver, for sure. Before you remove the covers, knock the three centre screws (around the HONDA badge) loose. They hold the central, fixed spool in place and are easier to loosen on the bike.

I might add: there are 3 soft copper washers on those 3 screws that hold the field coil in place: smooth them off gently with a flat file when reinstalling them tightly to the coil in the new cover, lest they weep oil afterward.

[Vintageguy]

As usual, excellent, concise, judgement-free advise. Love this Forum. Thanks to all who responded.

[BenelliSEI]

If you are in no rush, watch my 1976 Honda cb750 Project posts. I have to pull both those covers and strip them down, before getting them polished by a local guy. I’ll take a few extra photos and show the step by step, if you want? Let me know.

[MauiK3]

If you choose to clean the coil let it dry before installing.
You can clean it with something like mineral spirits to rinse gunk out of it. A light wash off with Brake Cleaner will also work, just don't use anything that will affect the insulation.

[newday777]

If you choose to clean the coil let it dry before installing.
You can clean it with something like mineral spirits to rinse gunk out of it. A light wash off with Brake Cleaner will also work, just don't use anything that will affect the insulation.

Diesel fuel is a good wash to degrease with.

[Kevin D]

John, I’m going into mine for a starter clutch repair, but I’m looking hard at that intermediate harness.
Mine intermediate harness is 53 years old and it’s never been any trouble. But I can see that wrestling it around might cause a problem. I also worry that replacement parts don’t measure up to OE.
I’ll pay close attention to anything you post up.

[BenelliSEI]

John, I’m going into mine for a starter clutch repair, but I’m looking hard at that intermediate harness.
Mine intermediate harness is 53 years old and it’s never been any trouble. But I can see that wrestling it around might cause a problem. I also worry that replacement parts don’t measure up to OE.
I’ll pay close attention to anything you post up.

Kevin…. Good to hear from you. I’ve used a few of those harnesses from vintagecb750.com and they will outlast us both! I’ll add a few photos when I pull the cover, for sure. Cheers, J.

[HondaMan]

John, I’m going into mine for a starter clutch repair, but I’m looking hard at that intermediate harness.
Mine intermediate harness is 53 years old and it’s never been any trouble. But I can see that wrestling it around might cause a problem. I also worry that replacement parts don’t measure up to OE.
I’ll pay close attention to anything you post up.

Kevin…. Good to hear from you. I’ve used a few of those harnesses from vintagecb750.com and they will outlast us both! I’ll add a few photos when I pull the cover, for sure. Cheers, J.

Me, too: I've used them on several engines and bought one for my own -sometime this winter when it gets a little warmer in the garage(!).

[Kevin D]

John, I’m going into mine for a starter clutch repair, but I’m looking hard at that intermediate harness.
Mine intermediate harness is 53 years old and it’s never been any trouble. But I can see that wrestling it around might cause a problem. I also worry that replacement parts don’t measure up to OE.
I’ll pay close attention to anything you post up.

Kevin…. Good to hear from you. I’ve used a few of those harnesses from vintagecb750.com and they will outlast us both! I’ll add a few photos when I pull the cover, for sure. Cheers, J.

Me, too: I've used them on several engines and bought one for my own -sometime this winter when it gets a little warmer in the garage(!).

There are early and late model harnesses offered
From my parts book:

31110-300-000 (Early) s/n ~1132192
31110-300-010 (Later) s/n E-2000001~

I don’t know the differences, think I’m going for the early with 11/70 build E 1068xxx

[BenelliSEI]

Kevin…. The one I have is listed as;

Alternator Stator Wire Harness, This Harness has the Same 7 Wire Plug as the OEM part and Hooks up Without Alterations. Replaces OEM # 31110-300-154

[BenelliSEI]

If you are in no rush, watch my 1976 Honda cb750 Project posts. I have to pull both those covers and strip them down, before getting them polished by a local guy. I’ll take a few extra photos and show the step by step, if you want? Let me know.

Pulled all the covers from my cb750K6 project yesterday. Wrote a detailed procedure. Check out page 13 on my build under Proiect Shop.

[Kevin D]

John, thanks for all that writing. Those two posts in your thread, 319 and 320, that would be an hour or more writing for me, plus the photos.
 I’m thinking to service the starter clutch, I will leave the coils in place on the cover, and the aux. harness is upstream.

Covers looking good.

[BenelliSEI]

John, thanks for all that writing. Those two posts in your thread, 319 and 320, that would be an hour or more writing for me, plus the photos.
 I’m thinking to service the starter clutch, I will leave the coils in place on the cover, and the aux. harness is upstream.

Covers looking good.
[/quot

Kevin…… for your work, you can just “hang” the cover off to one side. Leave it all hooked up and tie it back under the carbs. Have fun! John D.

[BenelliSEI]

Finished the alternator cover today and added a few pictures. See #340 in my K6 Project Shop File.

[BenelliSEI]

As usual, excellent, concise, judgement-free advise. Love this Forum. Thanks to all who responded.

So…. Did you take a crack at it?