Triumph 750 stator and rotor alignment issue

1979 Triumph T140E, a little over 8K miles, and by the condition I believe it. The clutch plates were stuck, so I stripped and cleaned the primary, putting new cush drive rubbers in since it was apart. Problem I noticed when I first removed the cover, is the rotor seemed to be sunk in about 1/2" from the edge of the stator ! Surely this can't be right ? :? Checked all the parts by the parts book, nothing missing ... and the sprocket to rotor spacer was the correct one. Anyway, I installed a thick washer ( .120" thick) from a Norton crankshaft, with the stock spacer, to try and make the rotor more flush. It's better, but still not flush. But then, I had to remove some of the end of the timing pointer for it to not rub ! :? Is this normal with later Triumphs ??? I'm sure my 650s weren't this bad. The picture below are WITH the additional .120" washer. Comments please ...

I believe it's normal.

nortriubuell said:

Is this normal with later Triumphs ???

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Yes that seems normal, I believe it doesn't cause any loss of electrical output
Here's a photo of my '78 T140V.

nortriubuell said:

I'm sure my 650s weren't this bad.

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Your 650 Triumphs would have had a narrower duplex primary chain instead of triplex (unless any were very late '73- 650 models ) which is why the stator is positioned further out on the 750 models.

nortriubuell said:

I installed a thick washer ( .120" thick) from a Norton crankshaft, with the stock spacer, to try and make the rotor more flush.

I had to remove some of the end of the timing pointer for it to not rub !

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I don't think there is much clearance between the rotor nut and the inside of the primary cover, so the extra spacer is probably OK-as long as there is some clearance between the nut and the cover?

Well, ya come to the rescue again L.A.B !!! Sure appreciate your pics too. As long as it doesn't cause a drop in electrical ouput, OK I guess. (Sure don't SEEM, or LOOK right though.) I've got a 1971 650 on the bench now, and it's not near as bad. :? Well, perhaps i'll take that spacer back out then, thanks alot L.A.B. !!!

The same question was asked in reference to a Commando a day or so ago. The topic was well-covered some time ago (L.A.B. has kindly put a link on the recent Commando post) and regular contributor Ludwig did an experiment where he put the rotor in a lathe and moved the stator in and out while measuring output to try to find the optimum position. he found it didn't make any appreciable difference at all as long as there was some reasonable amount of overlap between the two. This seems counter-intuitive however almost every later British bike seems to 'suffer' from this syndrome and I think L.A.B. has hit the nail on the head when he alludes to different chain widths and space requirements, This charging system was developed earlier than the later and larger British models, which needed to have beefed up primary drive systems to deal with more power, duplex and triplex chains resulted and the existing stators and rotors were obviously found to produce sufficient charging for their needs.

dave M, thanks for the additional information ! I finally got it all together and rode it, and it's charging at 14 VDC above idle. 8) Runs great, and got 50 mpg with some hard riding. It's also started first kick ... each time I've started it. Really fun to ride too, but noticed the back end is kind've "wallowy" at 80+ on curves. Maybe these OEM 32 year old shocks need replaced ???