What have you done with your bike/s today?

[muskrat]

G'day Col.
No worries mate. First did a few short laps around Lithgow, about 15 minutes, not a hint of smoke. Then dropped the primary off to check the timing (Boyer) but didn't need to touch it 35 degrees @ 4K. Then I punted her up and down Scenic Hill twice. I now consider her "run in".
I do need to get a new carb before I do any serious miles. The slide is like a prick in a shirt sleeve and the flange is warped so much I had to use a 1/16" O ring to seal it. Classic Bike Spares has one, https://www.classicbikespares.com.au/product/amal-premier-aluminium-932-carburettor-rh/   the last time I bought one it was 1/2 the price! Ho Hum.
Cheers

[Joolstacho]

Musky, I've received my JRC carb and I'm dead impressed with the quality. Beautifully made, straightforward installation, spare jets, gaskets, nuts, fuel line, all included, -half the price of an Amal in Oz anyway).
No, I haven't run it yet.

[muskrat]

G'day Jools.
I have a pair of them (Keihin PWK) on my cafe. Yes they are a good carb. I did have a bit of trouble tuning the twins on the modified A10.
CBS are just up the road so could have it by Friday. JRC's would be 3-4 weeks away.
Thanks for the thought.
Cheers

[orabanda]

My friend Leon's A7 LS is arising from the ashes in my shed.
This bike is from Collie, in Western Australia; it last ran in the 1950's.
His father commenced the restoration 30 years ago, but conceded defeat last year, and gave the bike to Leon. I have been assisting Leon with the restoration for 14 months; his dad doesn't know the rebuild is underway.
Two weeks ago it started; first kick!!
Leon will surprise his father with a trip to my shed soon, where he will be able to hear it run.
When Beesa Bill was alive I bought his alloy clutch pressure plate for my plunger & rigid A10's.

This plate is a worthwhile mod; Beesa Bill's legacy was to leave the drawing on his website; made a plate for Leon's bike yesterday and fitted; 0.002" run-out and a lovely light feel.
Richard

[Worty]

Ok, what the %^&* is happening.  Put the ATD on the bike a couple of days ago and it ran fine for 10m.  Went out today, got 20m down the road, opened it up to overtake a car and ....... bang spit bang.   Got recovered, whipped off the timing cover and .... fibre gear stripped again.

So, I reckon old fibre gears deteriorate with age regardless of appearance.  When I took the ATD off, the teeth seemed to crumble under a bit of pressure from a screwdriver - the modern gears don't do that.

I have now decided to rebuild both of the new units, and a another spare from the bits I have left over.  I reckon this is the answer as this is the fourth ATD I've demolished in 10k miles.  In case you ask, the timing gear pinion is fine, the maggie is not seized in any way, and I don't thrash the nuts off the bike.  To date, ATD failures have been 1) Gear stripped for ??? reason; 2) Unit starting to fall apart due to poor riveting from my 'mechanic friend'; 3) Catastrophic failure due to bob weight pin coming out and 4) Gear stripped for ??? reason.  Both 1) and 4) were old gears, 2) and 3) are self explanatory.

So, off the road for rebuilding .......... again.

[muskrat]

G'day worty.
WTF I think a change of name to Noluck is in order
I'm not sure but I think I remember seeing somewhere alloy pinions for the ATD.
I have an alloy non ATD pinion running Boyer on both of mine. I can't see why one couldn't be machined to suit the ATD.
Cheers

[Worty]

TBH Musky, I'm thinking the same.  Ok, maybe if the maggie seized up big time, the timing gear pinion could shred an alloy gear, but what's worse, an engine full of fibre fragments or an engine full of aluminium fragments.  In any case, how many times does the maggie lock so solid it'd shred an aluminium gear????

If there is a 'ready to go' aluminium replacement out there, let me know.  If not, a good business idea is open for someone to exploit.

In the meantime, I'm going to rebuild three units with modern fibre gears.  After all, one of the modern ones did last around 6k miles and was only replaced because my 'engineer friend' couldn't rivet the bloody thing together properly.

[Worty]

Exactly SHM, I reckon the gears were very old and had deteriorated to the point they'd got brittle.  Having an ally gear should be no problem, unless one has a catastrophic maggie seize up, but then you'd have the same problem as a fibre gear in trying to extract bits and pieces via the timing cover and sump gauze.  The new gears look far less 'swollen' than the old ones - maybe the answer is right there??

The only other reason I could think of for failure is putting a bit of load on the fibre gear against the pinion when tightening the ATD nut, but I'd have thought that was negligible.

Incidentally, any more ideas of how to lock the maggie up when tightening the bolt??

[Colsbeeza]

Worty and SHM,
 Last time I did the timing I was able to hold the ATD from moving.  I looked up my notes from March 2021 and had written this - "I used a screwdriver to prevent the ATD from rotating whilst tapping the bar on the socket. The screwdriver was inserted from front and beneath the ATD, and held against one of the flyweight holders". To avoid damage to the fibre wheel.
First attempt was successful. Il
I'll have to wait until next time to remember exactly how.
Col

[groily]

Priory Mags lists ali gears for use with ATDs or without.
Had one for ages on an ATD  on mine. It was good.
Some said 'it will be noisy'. It wasn't.

The 'fail safe' point re fibre is an irrelevance - ever seen a fibre sprocket on a Notrun?! All AMC twins use steel gears for the mags - fool proof.
In my life I've had 2 fibre ones go, 40 years apart. Four in a row is OTT and very bad luck Worty unless there is 'something else' at the root of the problem. Take it your armature is straight, no flop in bearings and the gear turns close-to-true?

Can't think of a better or easier way to hold the armature in position than through the earth brush hole.

(Whatever turns you on SHM!)

[Worty]

Priory Mags lists ali gears for use with ATDs or without.
Had one for ages on an ATD  on mine. It was good.
Some said 'it will be noisy'. It wasn't.

The 'fail safe' point re fibre is an irrelevance - ever seen a fibre sprocket on a Notrun?! All AMC twins use steel gears for the mags - fool proof.
In my life I've had 2 fibre ones go, 40 years apart. Four in a row is OTT and very bad luck Worty unless there is 'something else' at the root of the problem. Take it your armature is straight, no flop in bearings and the gear turns close-to-true?

Can't think of a better or easier way to hold the armature in position than through the earth brush hole.

(Whatever turns you on SHM!)

The maggie is straight from Priory, so no issues there.  I reckon I was unlucky with only the third failure, where the bob weight pin came out.  Two of the others had gears made of cheese, and one was a pathetic rebuild by my 'engineer' mate who couldn't rivet to save his life.

I'm going to try new fibre gears first, and see if they are ok.  Prior to this catalogue of problems, one ATD with a new gear lasted quite some time and only failed because of the bobweight pin issue.  The other one that had a new gear failed beause of the crap riveting issue.  This tends to suggest that a properly built ATD with a new fibre gear should be ok for the foreseeable.  I'll probably wish I'd gone for the ally gear in the end, although I still balk at the thought of ally shavings floating around the engine.

As for SHM, my mind is now full of unwanted images of how you motivate yourself to service your bike.  A sort of sado-masochist approach to motorcycle maintenance.

[Angus]

Hi Groilly and all. Owning a Norton (model 7), that become a notrun they do use a fibre spocket but for the dynamo  . 2nd one has just shredded and I am going steel. They are supposed to have a clutch so if the dynamo locks up it slips but something is wrong in there and so its a dynamo rebuild and a steel spocket, then find where the fibre has gone as no sump plate 
RDFella Its Andrews Holiday time and He has a backlog of emails I phoned him and he got me my bits next day

[groily]

Hi Groilly and all. Owning a Norton (model 7), that become a notrun they do use a fibre spocket but for the dynamo  . 2nd one has just shredded and I am going steel. They are supposed to have a clutch so if the dynamo locks up it slips but something is wrong in there and so its a dynamo rebuild and a steel spocket, then find where the fibre has gone as no sump plate 
RDFella Its Andrews Holiday time and He has a backlog of emails I phoned him and he got me my bits next day

Yup, fibre pinions in magdynamos, most of.
Some of the earlies (pre-war and pre MO1) used steel  - and no clutch.
The clutch thing is a 'some and some' question. Yes, it's supposed to slip to prevent troubles spreading as it were, but I tend to do 'em up tighter than Lucas said to avoid slippage in normal use, which grooves the 'plate' under the spider diaphragm something rotten ( and also creates a lot of heat). Some of the pattern spiders have no real spring to them anyway, compared to the originals so I don't believe the low Lucas torque figures necessarily apply. Teeth do get shed on these, 'tis very true - loads of grease in the end housing is a must because it's a PITA job to have to replace one if everything else is good. (And new ones do need a tweak to fit, in many cases.)
Is stating that ali gears are available, I wasn't particularly recommending them, just pîcking up on the question posed. In fact, I went back to fibre on my A when I got round to building a good ATD with a new gear, but not for any real reason except the mechanism was slightly better than the one on the ali. No shavings anywhere, though, so I don't think that's a serious problem if the gear has the right diametral pitch etc.

[RDfella]

Grrrrrrr     Took the GF out for a spin this afternoon, having replaced clutch pushrod and changed clutch plates last week. As soon as I pulled onto the main road, I thought - that's smooth. Or rather, slipping. Won't take any more that about 1/5 throttle or revs climb immediately. Top gear is a no-no.
This time I put ATF in the primary, instead of 2050. Worse than ever. I realise rigid and plunger owners are unlikely to suffer this, as those clutches were thoughtfully shielded from oil, but how S/A owners who put oil in their primaries get on I've no idea. Normally I run my chaincases dry, but put oil in this one when I fitted the elec starter, due to the extra gubbins in there requiring a splash now and again. My present thoughts are to drain the oil and run dry as usual and if the starter lasts 'till the winter, I'll then rip the clutch out and replace with a plunger item. Assuming the dome will fit inside the cases .....

[Worty]

Sorry about this RD, but I have oil in my s/a and never had a problem with slip - use 20/50.  Just can't think of why it might be slipping.  It would seem that my bike is more likely to shred ATD gears than suffer clutch slip????????????