[TR7RVMan]

Hi nhojk1, Short or open in wiring or voltage regulator.

What does bike use for rectifier, regulator?

Stock disc rectifier & zener diode, modern electronic regulator or what?

Has chain rubbed through wire? Can you see melted or heat damaged wires going into wire harness, or in rectifier/ regulator areas or anywhere else?

Can be a fight to remove. Rotor can get glued to stator. Pull both as a unit.

If stator metal poles rubbed rotor it can wipe magnetism out. Melted plastic can be cleaned off, but often not easy.

I’ve only seen two melted. One wire chafed & shorted on frame. Melting stator allowed poles to rub rotor. Both were obviously junk.

The 2nd one Tympanum regulator went open circuit. Stator overheated & partially melted, sagging & put plastic on rotor. Wire to stator & all chassis wiring was good.
New stator, modern regulator (used Lucas brand) cured. I cleaned plastic from rotor, reused rotor. Still working good.

Lots of options for replacement parts. Depends on what you want.

Stuart is expert on this subject. Follow his recommendations. Upgrade to high output 3 phase is wise choice. Requires modern regulator. Unless you are determined to keep all stock, upgrade is the way to go. The Asian Honda type regulator is good plan & doesn’t take much space.
Don

 

[TR7RVMan]

Hi Stuart, On the Bonnie I replaced stator & rotor on some years ago, one wire from stator had insulation worn through to ground. So direct short to ground.
The new parts cured problem.
Was it the short the real cause?
If the chain cuts wire, it’s a short to ground while conductor is touching chain. Then open after wire is worn through.
What is the effects to stator?

Ive not seen many 650 with cut wire, but the 3 row chain I’ve seen a few as chain is wider than metal tube.
This is important stuff. Hate to replace stator just to have it fail again! Seen that recently as you know.
Don

 

[TR7RVMan]

Hi, The inside of rotor should be threaded for puller similar to the original AAU. I've never personally pulled one. You may need to shorten stem of original puller or use slide hammer version puller. I'm not a fan of screwing in 5/16-24 bolt & knocking it sideways. However maybe just screwing in 5/16 bolt will act as puller & pop it off.

Regarding oil pump, I just received my new Morgo pump. Very high quality in every way. Of course I quality controlled it. Not a trace of leakage, absolutely perfect in every possible way. Finally a repro part that is actually quality! It indeed has a little more volume that original 650 pump, as both pistons have a little larger diameter, but less than the oval port genuine original Triumph T140 pump introduced in 1973. Morgo is for sure worth the $$. I've had a fair number of pumps off & apart. I always bench test them even new. Be sure to bench test your new Morgo. I've personally never had long term success with reseating balls. I won't do it anymore. Yes, lapping with fine compound can work. I've observed the seat wears oval & crooked. So even after lapping, reseating you often end up with a compromised surface that puts ball slightly offset. A new Morgo is never a waste of money if you old pump fails test. If old pump passes leak test & visual inspection of plungers, drive block etc. It's good. No reason to change it. Funny thing, new Harris pumps rival Morgo for price. I ordered from Morgo direct. I've seen so many failures trying to fix worn pump seats (even by me) I just won't do it anymore. Quality of all the aftermarket pumps is dubious. So it puts Morgo a world ahead.
Don