classic motorcycle forum

Just how do you "set the timing by moving the magneto gears"  ??
Or is that the time honoured method of tapping the gearwheel onto the taper, and then locking it with the nut ...

Whatever... within half a tooth would be enormously better than it is now.

Are you clicking it into neutral in the last little bit while rolling to a stop.
And from 2nd, or 1st
Or attempting it once stopped.

Neutral (deliberately) has a lesser notch to it, to prevent the 1st to 2nd shift from hanging up.
It can be a very finicky adjustment of the clutch to get this action just right.

Whomever rebuilt it could have improved/changed/altered this ?
Changing the gearbox oil can sometimes work wonders with the action too.
Ain't old bikes fun !

Do we have an example of a Waratah that is not an exact Excelsior model ?

I must have skipped class that day. Or my memory has slipped a cog.
And I saved all posts under W
Inc some from elsewheres .....

Thanks for that. I do have a couple of Mk XVI-A engine numbers (prefix AXF) from Waratahs so that will work.

I'm a bit confused because the Villiers book (Browning) says the Mk XVI-A has an "aluminium deflector piston" while Waratah guff in late 1935, for its 1936 model, says two exhaust ports (tick), 67x70 (tick), detachable alloy head (tick), full roller big end (tick), extra long gas tight bronze main bearings (tick), but "alloy flat top piston"!

The XVII-A (BYX prefix) had the flat top piston, but ball mains!

Not to worry - it's a 250 (notice I didn't say 247 or 249!!) Villiers. Should be enough.

Yes, R, all Waratahs from Excelsior from about 1930, prior to that from Sun Cycle & Fittings. Even Excelsior frame numbers, but not necessarily exact Excelsior models.

Cheers

Leon

Hi Billington,

In your photo the rubbing block is well past the opening ramp: when it is in this position the points gap should be about 0.012".

For most of the rotation of the magneto the points should be open about 12 thou; for the rest the points should be closed. Only when the rubbing block hits the ramps and begins opening the points will the gap pass (instantaneously) through 0.003". (And again when closing, but this plays no role in the spark.)

When BSA talks about the points being open 0.003", they mean that the rubbing block has hit the ramp and the points have opened about a quarter the way to fully open (0.012"). This defines an exact point in the rotation of the magneto.

You've asked for help, we've provided it with care an attention. Have you considered accepting it? Humour us. Try it out.

Cheers

Leon