newbie alt. question?

Not open for further replies.
Oct 25, 2008
hi all pulled my primary cover today to inspect . found alt. wires one frayed and bare wires exposed . looks likes pulling the alt. wires out of the housing pretty tricky let alone getting them back in . pulled the starter gave me a better look.probably replace alt. any way any one walk me thru sparxs 3 phase alt. installation and regulator on mk111 thanks m.c.
Hi M.C. I don't know about sparxs alternators and such, but I did have the same issue with getting the wires through the grommet. I found that it was important to use a new grommet because the existing one was really hardened (I suppose from heat and age). Then I coated the wires with silicon isolastic grease and it was suprising how easily they slid in!
PS, as I'm sure will be obvious, that thread takes you to an overview of installation on a Triumph, so there will be some differences in implementation. Still gives you a fair idea of what's involved.
mc1011 said:
any one walk me thru sparxs 3 phase alt. installation and regulator on mk111 thanks m.c.

It should be a reasonably simple job to do, but it will probably be better to go through it once you have the Sparx kit in front of you?
1) unplug leads from stator to main harness and pull them through the grommet. You may need to orient bullet connectors so they are pulled through one at a time as it is a tight fit.

2) Remove the four nuts retaining the stator and pull the stator off the four studs.

3) Remove the large nut retaining the rotor to the end of the crank. You will either need an impact wrench or lock the primary chain with a piece of hardwood to remove the nut with a wrench or socket.

Mount the new rotor and torque the center nut.

4) Slide the new stator over the studs, using the same spacers,washers, and nuts from the original. The cable should be emerge from the outer surface at about the 5 o'clock position. Using non-magnetic (brass) feeler gauges assure you have 0.008-0.010 inch clearance between the rotor and stator completely around the circumference.

5) While this is an optional step, it makes for a cleaner installation. Remove the wires from the rectifier and remove the rectifier. Tape back the wires to the main harness. Remove the wires from each of the two zener diodes on the Z-plates and tape them back to the harness. Remove the zener diodes and fill the hole with a nice polished stainless 1/4 inch bolt.

6) Decide on a suitable location to mount the new regulator/rectifier. This can be on the battery tray or any suitable spot. I don't like mounting them on the side cover or seat pan as they then must be disconnected when removing the seat or cover. I often make a simple aluminum bracket to bolt to the battery tray and mount the regulator/rectifier vertically.

7) Usually the grommet in the inner primary cover is hard and you now need to put three wires where there were two. I have been able to force the wires into a new grommet, but usually I will get a larger grommet or carefully drill the hole in the grommet larger to accept the cable. Many people seal this with RTV, but I don't find it necessary.

8 ) There should be sufficient wire length to connect the three leads from the stator to the three yellow leads of the regulator/rectifier, depending on where you decide to mount it.

9) Connect the black regulator/rectifier lead to the negative side of the battery and the red lead to a good ground or the positive side of the battery.

10) You will now find that your charge indicator light no longer works. Some people have found that connecting two of the yellow leads from the alternator to where the Green/Yellow and White/Green wires on the solid state assimilator restore the function. I have not had any luck with that, possibly due to a problem with the assimilator. In any event I remove the assimilator and tape back the wiring and install a "voltage switch" which turns on the charge light when the voltage is less than something like 11.5 volts, and goes out above 11.5. This is not much better than the original assimilator, but is easy to wire as it goes across the battery (or any normally powered wire and a suitable ground), and a wire to feed the light.

You could also wire in an ammeter or voltmeter, whatever you want.

OK guys what have I forgotten to mention here?
Sounds about right Ron. I overcomplicated things; remembering now the reason I had to deal with LH threads and other such was I was actually in there to do a 520 x-ring conversion, involving removing whole inner primary, and while I was in there decided it was a good time to do the Sparx upgrade.

Having said which, I recommend the 520 x-ring upgrade as well.
Isn't the mkIII a 3-phase already? Just fix the wires (soldering, heatshrink tubing, RTV) and leave it all stock. It has worked fine for over 30 yrs.
batrider said:
Isn't the mkIII a 3-phase already?

No, the MkIII had the high-output 180W single-phase (two-wire) RM23.
newbie alt.

thanks you guys are great .glad i pulled alt. nut wasn't that tight and had a little play on rotor on the keyed shaft.just waiting for parts.thanks again i'll let you know how it goes .m.c.
Not open for further replies.