Installing a Sparx 3-phase alternator. I need some help!

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Hello everyone. I had my first foray into a real Commando repair this past weekend. I bought a Sparx, 3-phase alternator and ignition system for my MkIII.

This repair is going to take longer than I had expected since I ran into a bit of a hiccup. It took forever to get the old gasket off the primary and when that finally happened, I hit a wall.

I can't seem to get the rotor nut loose. This is not a reverse threaded nut is it? :?:

I put the bike in second gear and had my girlfriend basically stand on the rear brake and that bloody nut would not come loose. it actually seems as though the rotor nut is a special size since none of my sockets would fit, so I was CAREFULLY using an adjustable wrench.

As I was really laying into that nut, everything was turning with it and I experienced a feeling of the engine sprocket being spring-loaded.

As I was trying to loosen that nut, the asembly would turn (counter clockwise) and there was a bit of movement but as I would loosen my grip a bit, it felt like the assembly would spring back as if it was loading itself or winding.

What am I doing wrong and how can I get this bloody rotor nut loose?

All help is very much apreciated.
 
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Oh dear!
You've got to get the correct socket I think it's a 1/2" whitworth. Use forth gear and the rear brake to lock the motor, load up the wrench anticlockwise and hit it with a hammer, the shock should free it unless the PO has loctited the darn thing on, then you need a little heat. For goodness sake take care not to bend the end of the crank.
Best of luck,
Cash
 
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As Cash says, a correct-fitting socket is essential and like most of the big ones on the Commando motor, they are Whitworth sizes and not American Unified AF.

I use a good strong 15" tommy bar and even then it's sometimes tempting to put an extra length of tube on it.

You are in effect winding-up the transmission so it will feel as if you are compressing something. It is not helped on the Mk111 by the fact that the rear disc has no self-servo effect and with static useage seems to "slip" instead of grip hard.

It might help to chock the rear wheel and get the braking assistant to sit on the saddle. If that still doesn't work then you need a heavier girlfriend :) (Not too heavy though or you'll have to buy a Harley or a Gold Wing !)
 
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cash said:
Oh dear!
You've got to get the correct socket I think it's a 1/2" whitworth. Use forth gear and the rear brake to lock the motor, load up the wrench anticlockwise and hit it with a hammer, the shock should free it unless the PO has loctited the darn thing on, then you need a little heat. For goodness sake take care not to bend the end of the crank.
Best of luck,
Cash

Thanks Cash.

I had the bike in second gear during my first attempt and I'll try it fourth gear later today. I don't have the proper 1/2" whitworth socket either and there is no place even remotely close to me that sells whitworth. I was using a big cresent wrench as that is what I have available.

Total nightmare.
 

L.A.B.

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A 15/16" A/F spanner size is only a tiny bit larger than 1/2" BSW (+0.018") so you could try that if you have one?
Or 24mm is a bit larger still (+0.025").
 
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L.A.B. said:
A 15/16" A/F spanner size is only a tiny bit larger than 1/2" BSW (+0.018") so you could try that if you have one?
Or 24mm is a bit larger still (+0.025").

Thank you! I was just about to ask the very question you are giving in your post.
 
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79x100 said:
If that still doesn't work then you need a heavier girlfriend :) (Not too heavy though or you'll have to buy a Harley or a Gold Wing !)

:shock: Yeah, shes maybe 110 pounds soaking wet.

I'll try choking the wheel as well. I never thought of that. Thanks!

Assuming I get that rotor nut off, anyone know what to torque setting I use to it back on?

Also the torque settings for the primary cover bolts.

Thanks.
 
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I probably should buy the BSW Whitworth sockets any way. Should I get 6 or 12 point?

Is Koken a good alternate brand?
 
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I probably should buy the BSW Whitworth sockets any way. Should I get 6 or 12 point?

Is Koken a good alternate brand to Whitworth?
 

L.A.B.

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Coco said:
Is Koken a good alternate brand to Whitworth?

Not quite sure what you mean? As Whitworth (BSW) isn't a brand, it is a thread form type.
 
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I just finished doing some work in my primary and had some issues with undoing the rotor nut this time . I use either a metric or imperial socket and a very brief blip with an impact gun .. The nut is free in a second .. No need to hold down anything ..

Getting off the subject for a second , Where did you by your Sparx kit as i am looking at going the same route ..

Thanks , and good luck
 
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Once the box was in 4th gear I tied the brake lever down to the underside of my hydraulic bench with a strong ratchet strap. I found I can get more leverage on it than my partner can give it, she's only little.
Also like Ron I've used an impact gun for things like this although my rotor nut came off OK with a long bar on the socket.
good luck
millard
 
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L.A.B. said:
Coco said:
Is Koken a good alternate brand to Whitworth?

Not quite sure what you mean? As Whitworth (BSW) isn't a brand, it is a thread form type.

Ahh, I see. I thought Whitworth was a brand like Craftsman or Snap-On.
 
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Ron Hulton said:
I just finished doing some work in my primary and had some issues with undoing the rotor nut this time . I use either a metric or imperial socket and a very brief blip with an impact gun .. The nut is free in a second .. No need to hold down anything ..

Getting off the subject for a second , Where did you by your Sparx kit as i am looking at going the same route ..

Thanks , and good luck

I got mine from Rocky Point Cycle and a single coil conversion from CNW. CNW actually sends you a nice bracket to mount the voltage regulator on (which Matt actually sent me) so I would just get everything from CNW to save your self a bit of grief. Matt at CNW is awesome and has been a huge help in getting me going with everything.
 
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Note that when you go to fit your Sparx rotor its bore is undersize to allow it to fit worn crank mainshafts, if yours is not worn then the bore will need opening up.
 
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kommando said:
Note that when you go to fit your Sparx rotor its bore is undersize to allow it to fit worn crank mainshafts, if yours is not worn then the bore will need opening up.

I did not know that.
 
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I put the primary cover and gear lever back on so I could shift the bike up to 4th to hopefully have a better grip on getting that rotor nut off.

It won't shift into 4th! :shock: Just 1st, neutral and 2nd.

WTF?

If I had any hair left I'd be pulling it out right about now.
 

Ron L

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Turn the rear wheel slightly (engine off, of course) while attempting to engage the gears. You should be able to engage 2nd, 3rd, and 4th in this manner.
 
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Ron L said:
Turn the rear wheel slightly (engine off, of course) while attempting to engage the gears. You should be able to engage 2nd, 3rd, and 4th in this manner.

Bingo!

Thanks Ron.

It's still strange why it wouldn't shift up simply using the gear lever without turning the wheel. Explanation?

I put everything back together correctly (I assume) so one would figure shifting would be like it was before I took the primary cover off.

Have pity as I'm a total noobie to motorcycle repair.
 
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Can anyone confirm that the rotor nut is regular or reverse thread?

I have been trying to take the nut off counter clock wise but I have a feeling the rotor nut is a reverse thread (clock wise removal).
 
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