3 phase vs single phase

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Oct 29, 2023
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I have a 3 phase set up on my 1975 Commando. the stator is cracked and breaking up. Can I just replace it with my single phase stator without changing anything else? Just plug it in and go?
I have heard that the 3 phase stators can overhear, crack and fail.

Tks
 
I had the same problem. After burning up two 14.5A 3 phase stators, even after increasing the rotor/stator gap, I went back to my original 10A single phase stator and now all is well (hooked up to my Trispark 3 phase regulator like kommando stated). No charging issues even with a cNw electric starter (I also have all LED lighting). Trispark now only recommends and sells the 10A single phase stator for use with their regulator.
 
The instructions on the Tri-Spark regulator/rectifier states that it can be used with either 2 or 3 wire stators.Finding a 10.5 amp 3-phase stator can be a challenge
Mike
 
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The current 'Lucas' is a copy with the Lucas brand licensed/rented by Wassell to add a thin fragile coating of genuineness.

There are 'Lucas' 10.5A 3 phase around, how they perform in terms of longevity compared to the 16.5A I have no knowledge.

 
I burned up two 3 phase in short order on the 74' Commando I just rebuilt this past winter. I attributed it to having adjusted the primary chain too tight, causing excessive crank flex, and sloppy tolerances from the stator and rotor manufacturing. I also run the Tri-Spark MOSFET. In my frustration, I bought a Sparx 3 phase and had .010 shaved off the rotor, which is also a Wassel/Lucas replacement. Then, using a strip from a soda bottle as a spacer/gauge, I turned the engine over about 1/8th of a rotation each time and marked where I was still getting a tight clearance. Next, I used a Dremel to take away material from each place I experienced a clearance issue. Sounds extreme, I know, but after $400.00 burning up, I was willing to try anything. The Sparx stator is much cheaper than the Lucas.
Looser primary chain and more clearance and I am getting 14.6 Volts at the battery when revving the engine. So far, so good. I have installed several 3 phase stators and Tri-Spark MOSFET on unit Triumph using the soda bottle spacer and have had no problems. I think the over-tight primary chain pulling on both the gear box and the crank shaft have played more of a role than heat generated electrically. I admit, I am just a hacker and make no claim to know anything. I just have suspicions ....

IMG_8585.jpeg
 
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I burned up two 3 phase in short order on the 74' Commando I just rebuilt this past winter. I attributed it to having adjusted the primary chain too tight, causing excessive crank flex, and sloppy tolerances from the stator and rotor manufacturing. I also run the Tri-Spark MOSFET. In my frustration, I bought a Sparx 3 phase and had .010 shaved off the rotor, which is also a Wassel/Lucas replacement. Then, using a strip from a soda bottle as a spacer/gauge, I turned the engine over about 1/8th of a rotation each time and marked where I was still getting a tight clearance. Next, I used a Dremel to take away material from each place I experienced a clearance issue. Sounds extreme, I know, but after $400.00 burning up, I was will in to try anything. The Sparx stator is much cheaper than the Lucas.
Looser primary chain and more clearance and I am getting 14.6 Volts at the battery when revving the engine. So far, so good. I have installed several 3 phase stators and Tri-Spark MOSFET on unit Triumph using the soda bottle spacer and have had no problems. I think the over-tight primary chain pulling on both the gear box and the crank shaft have played more of a role than heat generated electrically. I admit, I am just a hacker and make no claim to know anything. I just have suspicions ....

View attachment 124432
Don't use Diet Cola bottles, - you won't get enough clearance 🤣
 
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