Tri-Spark Ignition Rotor

[aso215kd]

While preparing to remove the inner timing cover, I found the Tri-Spark rotor and stator had significant wear on them rather than the 2mm clearance.  Come to find out, the rotor would not set down far enough below the stator ledge.  Has anyone else had to address this issue?
Cheers,
David

[limeyrob]

Could it be excessive end-float?

[aso215kd]

Thanks limeyrob, but no, thank goodness.  I called the Tri-Spark folks in Australia and they said there is an optional rotor that is shorter for certain applications.  Apparently the A-65 is one of those applications.  The previous owner obviously wasn't aware of this.  I have to say the bike was running fine with the the rotor and stator grinding on each other, but chances are it was waiting for me to be 100 miles from home before failing.
Cheers.

[limeyrob]

Makes sense. Many years ago I fitted a Lucas RITA to an A65. There wasn't  RITA kit for the BSA, only the Bonneville and I recall it was a very tight fit that took a certain amount of filing.  Worked great.

[limeyrob]

This popped up in my YT feed this morning (slightly creepy) but at 9:50 he's installing the stator and rotor so you may be able to see the length difference.
https://www.youtube.com/watch?v=cNzcDWOtFSQ
 

[aso215kd]

Yes sir, slightly creepy.  I ordered the shorter rotor and a replacement/updated stator in the event there is heat damage to the stator.  Thanks for your input.

[Allan G]

sounds like you have a later idler pinion (1970 onwards) fitted with an earlier (pre 1970), the later pinions have a reduced portion at the end which the later oil seal runs on, but it also pushes the rotor further outwards. I would verify what you have fitted first.

Whilst its presently working fine, the machining action of the two parts may cause the magnets to loose some magnetism - leaving you stranded.