Another failed Sparx stator

I like seeing the thoughtful satisfying protective custom lead mount. I zip tie the cord to the mounting boss and also leave in fastened on removing inner cover and don't disturb the seal passing out the cover either. What we must put up with till they come out with electricity generating mufflers.

Tim_S said:

I've had more than one sparx rotor go flat on me the last couple years. Lost it's magnetism.......usually the stator encapsulation comes apart but never had the wires burn like that.
Let us all know if they give you a new replacement please.........

Tim_S

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I had a brand new Sparx rotor loose its magnetism and of course its ability to charge. When I removed the stator looking for an answer as to what had happened I noticed the the nuts and washers didn't stick to the rotor, that was my ah ha moment. I had gotten it from AMR in Tucson and Mike sent me a new one right away. Don't ride that bike as much as I should so I am not sure how it's doing. I had purchased 2 at the same time, one for my Domi 88 and the other for my 74 850. Just recently, on my regular ride a 74 850 Commando the insulation around the wires broke and shorted out. Tried to do a fix but that didn't work either.
I wish that who ever makes the replacement stators would use Teflon coated wires and mold the wires coming out to run parallel to the stator instead of coming straight out. I know wish in one hand and.....in the other.

John in Texas

A few points about the Sparx 3 phase alternator system:

1) They run tighter, clearance wise, than almost any other stator/rotor combination; more gauss means more power, and over a wider RPM range.
2) Nortons stators (regardless of mfg.) mount on the three studs that are threaded into the inner primary case which is fastened to the drive side engine case with 3, 1/4-20 x 5/8 hex head bolts, not a lot. Mk3s don't seem to have this issue with the "double deck" above the starter/rotor system.
3) Even if the inner primary is PROPERLY fastened to the drive side engine case, imagine the torque load those 3 fasteners bear when you whack the throttle at 3000 RPM?
4) Triumphs have next to no Sparx failures. Studs tapped into drive side engine case.
5) Sparx Norton failures display heat/melting symptoms predominately between the 1:00 and 3:00 positions.
6) Sparx alternator systems are no longer available to me from and importer that was importing over $200K a pop; you got that kinda change?

The bottom line for me is that the Sparx 3 phase system was incorrectly designed for fitment for the bulk of Nortons, some even with properly torqued fasteners, but with excess manufacturing tolerance in the relationship between the drive side engine case and the inner primary cover. I suspect that the Chinese (or other profit minded entity) designed the Sparx 3 phase system to the center of the Norton factor tolerances.
I have personally warranted 3 systems and I couldn't find enough ketchup to make them palatable. I no longer sell any thing Sparx, Although I have one of their 3 phase units on my '72 Mk 1 Combat that is (currently) performing yeoman's service, go figure...

If my Sparks fails I'll probably share some fault by letting it hang by the wires while doing other work.

Adrian1 said:

Al-otment said:

Problems I've noticed with the later Lucas stators is that the cable sleeving is not heat and oil proof and goes hard, fractures and then allows hot oil onto the alternator wires and subsequently the insulation on these cracks and a short results. I've sleeved the alternator wires with the heat resistant fibreglass/acrylic sleeve, using epoxy resin to seal it to the stator. http://www.vehicle-wiring-products.eu/V ... heatresist. More customer fettling that's required on new parts.

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Well actually these are oil cooled stators :wink: FWIW the older Lucas stators had no encapsulation and did their job for many years - as is the original one in my 1957 Enfield Crusader still does.....

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Having worked (now retired) in high power electromagnetics for over 40 years, I can comment on "encapsulation".
Based on the magnetic strengths effect on the wires in the stator, the varnish coated wires can be physically be moved each time the magnetic field moves through the wire. In a case of very high fields I have seen fat wires JUMP when a high power field get passed through the wire. I will assume British electricity uses the same physics as what I worked on...
After long term use, the wires of a NON potted coil will chafe on each other and eventually short to each other. This is why the high power coils were potted ...which was to physically restrain the wires against chafing.
I believe the stators were potted for this reason. Poor vacuuming processing will fail to fully hold the wires and eventually fail electrically.
A high current load will move the wire and an open wire will not be moved...

Guy`s bear in mind Lucas have not produced new Stators between 1995 - 2014

So if you have a genuine Lucas unit the insulation could be hard and brittle

concours said:

grandpaul said:

Looks like some damage to the wiring insulation against the inside face of the primary cover. Could that have contributed, or caused the problem?

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Nary a mark inside the cover, I looked :idea:

The burn mark up at 2:00 is telling.

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Failure analysis of electromagnetic components was part of my job for a good part of 10 years.
Most likely NOT shorted to ground in any way :?:
Since it's a 9 pole, cut all 9 sections apart and don't disturb the potting.
Do an OCL measurement and resistance measurement I'll bet both are low due to a partially shorted coil...now turned into a self energized heating element :mrgreen:

Then dissect/remove potting to verify and maybe find voids in the potting?

dynodave said:

concours said:

grandpaul said:

Looks like some damage to the wiring insulation against the inside face of the primary cover. Could that have contributed, or caused the problem?

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Nary a mark inside the cover, I looked :idea:

The burn mark up at 2:00 is telling.

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Failure analysis of electromagnetic components was part of my job for a good part of 10 years.
Most likely NOT shorted to ground in any way :?:
Since it's a 9 pole, cut all 9 sections apart and don't disturb the potting.
Do an OCL measurement and resistance measurement I'll bet both are low due to a partially shorted coil...now turned into a self energized heating element :mrgreen:

Then dissect/remove potting to verify and maybe find voids in the potting?

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You are correct in the failed units I tested. Shorted windings -but not to ground.
No sign of rubbing.
I didn't go far enough to be able to say if it was incomplete potting but that would be most likely. Jim

i've gone through a number of encapsulated stators over the years. the brittle exit wiring was a common problem. i always wonder why none of the manufacturers simply installed a set of screw terminals, rather than the vulnerable pigtail. would make both maintenance and repair to the wiring much simpler.

speedrattle said:

i've gone through a number of encapsulated stators over the years. the brittle exit wiring was a common problem. i always wonder why none of the manufacturers simply installed a set of screw terminals, rather than the vulnerable pigtail. would make both maintenance and repair to the wiring much simpler.

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+1

I have fixed a number of stators with brittle shorted wiring over the years by grinding into the potting and following the wires to the other side of the stator and soldering in new teflon insulated wires. The teflon coated wires last pretty much forever.
It might have cost an extra .50 cents each to use teflon wire originally. Jim

Has anyone experienced any issues with the Trispark stators? Are these made by Trispark, or do the get them from an OEM?

Tri Spark stators were produced in China

Not sure if they will be around much longer though as TRI CORE / Sparks is pulling out and selling off his stocks at present

Frankie17 said:

Tri Spark stators were produced in China

Not sure if they will be around much longer though as TRI CORE / Sparks is pulling out and selling off his stocks at present

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I think you mean SPARX (Tri-Cor England)?

Tri-Spark is a different (Australian) company.

hobot said:

I like seeing the thoughtful satisfying protective custom lead mount. I zip tie the cord to the mounting boss and also leave in fastened on removing inner cover and don't disturb the seal passing out the cover either. What we must put up with till they come out with electricity generating mufflers.

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Here is a picture of my Sparx stator. It has been in my bike for about 8 years. As you can see the insulation has broken away from the wiring .

Ugh Peel had similar Sparx damage after a crank nut came loose to swirl around but was able to put RTV between to keep on trucking. Peels over rev event rubbing rotor into stator laminates heated the nice green resin to nasty toasted dark brownish color but was able to sell it off to someone thats still charging with it. Luck of the draw can get any of us so to me its another manhood will power tester not to quit the ongoing hassles cutting into ride time with decreasing life time left.

To be fair though my and my buddy Wes Suzukis have vital electrics fail and forums on all moderns are full of warnings and work arounds on rather harder to access and find and fix faults, usually by some other brands components.