classic motorcycle forum

Are you guys ensuring that the clutch lifts perfectly evenly and squarely ?

If it worse when hot, then things have expanded a bit.
Backing off the springs a shade may be required ?

Are you snicking into neutral in the last bit of rolling to a stop.
And tried changing the gearbox oil....

My little Waratah 125 was bought from the original owner - decals still (mostly) visible.
He bought it from Williams Bros in Wentworth Ave in Sydney with his army demob pay.
And then rode it the 400 odd miles out to Hillston.
Think he said it took 2 days, but not sure on that.
At 30 mph, thats 13 hours !
Used all his petrol rationing coupons (4 ?) to do it.

Surviving bikes show differences in those toolboxes also, so its not just brochure creep ?

P.S. Tom Byrne in Wentworth Ave was the Excelsior Dealer then. 
About 100 yards up the hill from P & R Williams.
From advertising, the Excelsior was either 5 or 15 shillings dearer.
Byrnes did Triumphs also, and went on to become the main BMW Dealer.

Powerhouse Museums example
Their thick gold pinstripe is different to my thin gold twin pinstripes.
Maybe someone got it wrong ?
https://en.wikipedia.org/wiki/Waratah_motorcycles#/media/File:1948waratahmotorcycle.jpg

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 !

No wonder the factory was getting back lotsa bikes with faulty running !
Sounds diabolical.

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 ...

I was involved in the earlier posts !
Having a just postwar 125cc.
Bought from the original owner.
Identical to the Excelsior bar the black (vs maroon) and the decals.
And a few shillings in price.
The 2 shops were only a hundred yards apart in Wentworth Ave.

But don't recall exploring how this evolved pre WW2 ?
The Meritor wasn't mentioned ?

It is not entirely clear (to me) what method you are now going to use to set the ignition timing,
but I'd comment that if it is not going to verify that it is sparking at that 3/8" BTDC at full advance,
then we might be back to square one ?

And, the fuzzy logic of "hot gases" escapes me also. If BSA increased the tappet clearance, it is
very likely that they found the valve was growing with heat, until it lost any clearance.
At this point it may/would/could start losing compression - which may make them
a) difficult to restart
b) begin to burn a valve, since the hot gases would/could be continuously escaping.
And this would not be good.
Hopethishelps
Have fun !

Thing is, if it was shite in the float bowl it would cause problems whether hot or cold..

While this is quite true, I have found that cold engines are very sensitive to this,
and once warmed up they will start near regardless.
Even if they then run like a dog - but this instantly tells you something is up.

Could the easy start spray to make it start be because of a weak spark ?
I have enough old iron that I keep a spare magdyno on the shelf.
This ensures they never play up !
The 1932 version may be a bit pricey for this, and it can be a lot of work to swap over.
But worth considering if this persists ?

Someone here had persistent starting problems, and borrowed such a spare maggie to try.
It proved equally difficult, but in the course of this the earthing path was improved.
Instant success !  Think laterally ?

Sounds like a failing condensor again, doesn't it. !
Do you know what the rebuild used - not a NOS one, we hope. ?

Another possibility is vapour lock.
Have you checked to see how warm the carb/manifold is when you pull up.
Those heat insulating tufnol type gaskets were added to many a model,
to help prevent this happening in hot weather.

So if you pour icy water over the carb and it still won't start, then try it over the maggie.
Preventing water ingressing to inside the works - a tricky situation.
Have fun, tell us how it goes ...