Sparx 3 phase alternator, Does this look right?

htown16 · May 25, 2012

Has anyone else installed a Sparx 3 phase alternator? Here's one I have recently put on my 72 Commando.

Sparx 3 phase alternator, Does this look right?

The rotor nut has several threads showing. I used a .33 shim and the spacer behind it. The flange on the nut is against the rotor and torqued to 70 ft/lbs. The sprocket and spacer between it and the rotor are tight. The sprocket also aligns pretty well with the clutch basket so I am assuming it is seated okay.
The other concern is how far the stator is proud of the rotor. I used the factory spacers behind the stator. The outer cover fits on with no problems.
Am I worrying about things that I shouldn't.

L.A.B. · May 25, 2012

Here's a previous thread on this subject: https://www.accessnorton.com/NortonCommando/alternator-installation.6247/

pete.v · May 25, 2012

I think it looks pretty good and pretty. My only real concern is that there is enough threads engaged on the center nut.

They say that the rotor only need to to 2/3 third into the stator. I felt more comfortable having it a little more engaged by reducing the width of the stator mounting spacers. Personal preference I guess.

radiofun · May 25, 2012

Mine looks exactly like this. What's puzzling is that the Sparx rotor and stator are the same widths as the Lucas parts. Have you figured out what to do? Use a smaller spacer behind the rotor? Is this a common problem, and if so how come Sparx or Colorado Norton Works doesn't say anythining about it or provide another spacer?

htown16 · May 25, 2012

The rotor nut is fairly deep and I had to wind it on a fair number of turns to get it to this. As far as the stator sticking out beyond the rotor, I could grind the spacers down some, but then I would worry about getting it crooked. As it sits a .008 feeler gauge goes all the way around nicely.

radiofun · May 25, 2012

The rotor nut threads on all the way. So would adding a washer behind the rotor to bring into alignment with the stator be a good solution?

htown16 · May 25, 2012

Bringing the rotor out is only going to make the problem with the rotor nut worse. Is your bike currently running with the alternator like this?

DogT · May 25, 2012

I'm still trying to figure the end result of SDave's problem at alternator-installation-t6704.html the thread ended up with a treatise on 2 and 3 phase and I'm not sure if he ever got his rotor and stator in the same plane. I'd like to see what happens here too because I'm thinking about the Sparx at some point. Or maybe I'm obtuse? I am old and slow.

Dave
69S

swooshdave · May 25, 2012

DogT said:
I'm still trying to figure the end result of SDave's problem at alternator-installation-t6704.html the thread ended up with a treatise on 2 and 3 phase and I'm not sure if he ever got his rotor and stator in the same plane. I'd like to see what happens here too because I'm thinking about the Sparx at some point. Or maybe I'm obtuse? I am old and slow.

Dave
69S

rgm-belt-illustrated-install-guide-t6750-15.html#p73331

I don't recall how it got resolved but even finished the rotor wasn't fully flush with the stator.

DogT · May 26, 2012

Dave, do you remember if you used shorter spacers for the stator? I have a faint recollection of someone doing that. But then I also remember hearing that the flushness of the rotor to the stator was not that important as far as output.

Dave
69S

pete.v · May 26, 2012

DogT said:
Dave, do you remember if you used shorter spacers for the stator? I have a faint recollection of someone doing that. But then I also remember hearing that the flushness of the rotor to the stator was not that important as far as output.

Dave
69S

I did this with 1/8 shorter spacer right out of the bins at the hardware store. I brought along a mic to make sure i got 3 that were all equal.

radiofun · May 26, 2012

Mine looks just like yours, htown, and the nut is completely threaded on. so bringing the rotor out a little (~3mm) will still leave plenty of threads attached to the crank.

Given what everyone has been saying, it seems like leaving it as is, that is with the rotor and stator slightly unaligned, will work just fine. so, I'm inclined to leave it as is and not put a spacer behind the rotor.

grandpaul · May 26, 2012

All you need to do is shorten the stator spacer to the point that you just have 1/8" - 1/4" clearance to the primary drive.

radiofun · May 27, 2012

swooshdave said:
DogT said:

I'm still trying to figure the end result of SDave's problem at alternator-installation-t6704.html the thread ended up with a treatise on 2 and 3 phase and I'm not sure if he ever got his rotor and stator in the same plane. I'd like to see what happens here too because I'm thinking about the Sparx at some point. Or maybe I'm obtuse? I am old and slow.

Dave
69S

Click to expand...

rgm-belt-illustrated-install-guide-t6750-15.html#p73331

I don't recall how it got resolved but even finished the rotor wasn't fully flush with the stator.

So Dave, No charging problem even with the rotor and stator not perfectly aligned? If that's the case, I'm inclined to button her and see how she runs.

swooshdave · May 27, 2012

radiofun said:
So Dave, No charging problem even with the rotor and stator not perfectly aligned? If that's the case, I'm inclined to button her and see how she runs.

Well, that's debatable. But I did ride all last summer without any charging problems. But this year might be different.

pete.v · May 27, 2012

swooshdave said:
radiofun said:

So Dave, No charging problem even with the rotor and stator not perfectly aligned? If that's the case, I'm inclined to button her and see how she runs.

Click to expand...

Well, that's debatable. But I did ride all last summer without any charging problems. But this year might be different.

Hey RF, you seem to have very good surface area to the rotor/stator. Better than most. Recheck 10 thou all around and button er up.

htown16 · May 27, 2012

Thanks for all the input. I believe I shall button it up as is. Once I get it running again I shall use my handy dandy one ohm resistor to check the alternator output under load. Nine volts and you're good to go. If not, it won't be too much of a problem to pull the stator off and find some shorter spacers.

radiofun · May 27, 2012

Htown, I found some 3/8" spacers at the hardware store and replaced the stock ones, which were close to 1/2". Better alignment now. I think I'm good to go.

Sparx 3 phase alternator, Does this look right?

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