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Messages - 33d6

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1
British Bikes / Re: Hot Start Problem
« on: June 29, 2025, 03:15:33 AM »
Of course the magneto could fail after little use. Age and how it has been stored since last done can have serious consequences regardless of mileage done.
I’m currently amusing myself with three radio controlled helicopters. All N.O.S, all received in their original unopened packaging, all looking perfect but all non running due to battery failure through sitting around for the last ten years or so. Electrical equipment can do that if left sitting. Look good externally but moulder away internally. Very frustrating but that’s how it is.
As R says it could also be vapour lock. Side valve engines do tend to run hotter than their OHV equivalent and I have seen some poorly thought out fuel line arrangements as well as R’s failure to fit a Tufnol heat barrier twixt carb and cylinder.
Nevertheless I tend towards electrical failure as my own experiences with vapour lock have been on stinking hot summer days with the engine smelling like a fifty year old fish and chip shop on a busy Friday night. Not just a mere hot start issue.
Tell us how you get on.

2
British Bikes / Re: ACME aussie bike
« on: June 11, 2025, 10:49:41 AM »
This bike is still on eBay but now down to $4k. Maybe this is one of those reverse auctions where the price keeps dropping until someone starts to bid?
I’ll keep watching (if I remember).

3
British Bikes / Re: Villiers XIIC 148cc doesn’t run anymore
« on: June 08, 2025, 09:57:02 AM »
There isn’t much comfort in checking the mainshafts for truth. New mainshafts aren’t to be had. Villiers mainshafts of the period are integral with the flywheel. They can be be ground circular undersized up to .005-.010” off but the centres have to be unmarred and dead true plus be set up dead true to the big end assembly. Not an easy job. I’ve chewed this job over and over, reluctantly coming to the conclusion it’s probably just as easy to make the whole assembly new from scratch. Either way is a drama.
On the plus side the two crankshaft halves are identical which is both a blessing and a curse as it both makes the job easier but is wide open for enthusiastic owners to unwittingly end for end the crank assembly when putting things back together. The wear patterns are different for each side so end for ending speeds up the wear rate until the original patterns reassert themselves.
Old British two-strokes are of dead simple construction but quite subtle to get running really well. Charging in with lots of enthusiasm rarely ends well.

4
British Bikes / Re: Villiers XIIC 148cc doesn’t run anymore
« on: June 07, 2025, 02:42:45 AM »
If you have pulled the engine apart and removed one bush it is best to replace the bushes on both sides to make a proper job of it. Replacing one bush alone is usually just a short term repair, replacing both has long term benefits.
I don’t know of anyone supplying these bushes but as they are so easy to make I just make my own. They can be made of any common phosphor bronze bearing material, there is no benefit in using anything fancy or special. This is a very ordinary job for any skilled machinist.

5
British Bikes / Re: Villiers XIIC 148cc doesn’t run anymore
« on: June 02, 2025, 08:46:46 AM »
Villiers advised up to .008” wear was acceptable. Whether bushes or crankshaft are worn is irrelevant. It is combined wear that counts. Essentially though, if it’s an easy starter, leave well alone. I find the major problem with old Villiers engines is that owners can’t resist pulling them apart to then find they’re never quite the same afterwards.
I think the fussiest area revolves around the ignition timing and the points. The points cam is on the end of the crankshaft so is directly affected by mains bush/crankshaft wear plus the points pivot hole in the points box wears so the action of the rocking pivot point gets erratic. It’s fascinating to watch when using an ignition timing light. You have this blurred line wandering 4-5 degrees each side of the timing line.
I don’t worry overly much about overheating. All cast iron fixed head two-strokes running a cast iron piston run hot. They cannot do otherwise. Just be enthusiastic with the oil.


6
British Bikes / Re: Villiers XIIC 148cc doesn’t run anymore
« on: June 01, 2025, 11:49:58 PM »
Yes, that is correct. The vertical surface of the deflector  faces the transfer  port.

7
British Bikes / Re: ACME aussie bike
« on: June 01, 2025, 07:14:11 AM »
As an aside that may explain the common problem of finding wheels for various projects. In my apprenticeship youth it was common to see various workshop mobile devices rolling around on motorcycle wheels. Oxy/acetylene sets spring to mind. Much easier to get a large wheeled set across a muddy plant park to the dozer you were working on than the usual indoor set with tiddly little cast iron things. It was traditional for the apprentice to get the muddy and clumsy jobs in the far end of the plant park. Particularly if it had been raining for the past few days.
We had a variety of odd carts with odd motorcycle wheel set ups. All for lugging various bits and bobs around and what’s the point of having an apprentice if he isn’t the one doing the pushing and pulling?
Now I know there wasn’t an alternative wheel source.

8
British Bikes / Re: Villiers XIIC 148cc doesn’t run anymore
« on: May 31, 2025, 05:56:41 AM »
Personally, it sounds like a fuel problem. Not enough fuel getter to the carburettor. Could be anything from a blocked air hole in the petrol cap or half blocked fuel tap but I particularly distrust modern in-line fuel filters. They are not made to to pass a mixture of petrol and oil.
Best of luck.

9
British Bikes / Re: ACME aussie bike
« on: May 31, 2025, 03:58:40 AM »
It’s a fine line between ‘manufacture’ and ‘assemble’. Acme erected their own frame. Who made the tubing? Who made the lugs? I would expect Australian made tubing, but what about the lugs? Did buying the Webb forks include the headstock lug? I don’t know.
What about the wheels? The hubs were imported but what about the spokes and rims? I would expect spokes to be made locally but what about the rims? Dunlop were popping them out by the gazillion. Could local manufacture compete given the economies of scale?
So it goes on.
What Bennet & Wood did was no different from many other small motorcycle factories of the time. Lots of proprietary parts but their own vision. I’ll accept ‘maker’.

Last thing. The prewar Acme silencer was merely a Coventry Eagle job mounted upside down. Postwar C/E were gone but there was now a thriving local aviation industry looking for work. Pressing out Acme silencer halves was no different to pressing out lightweight aeroplane bits and pieces. Problem solved.

10
British Bikes / Re: ACME aussie bike
« on: May 29, 2025, 04:04:58 AM »
The tank is right and the joy of these little lightweights is that they are made up from proprietary parts from a multitude of different firms. What parts of an Acme were actually made by Bennett & Wood? Very, very little.
It’s not like finding all the parts for a 1947 Norton or Triumph where you always have some numbnut looking over your shoulder saying things like “Oohh, you’ve got a chrome plated giggle pin there. They didn’t do that until engine number such and such.” Or some other equally tomfool remark. No one ever looks at an Acme in that way.
Yes, it’s no cheaper to restore a lightweight than anything else. So? What’s the problem? It’s a hobby and people pursue hobbies for fun.
If you’re not enjoying it why are you doing it?

11
British Bikes / Re: ACME aussie bike
« on: May 29, 2025, 01:40:09 AM »
Well, no more parts missing than the average stripped down chook chaser and as far as a “comp” engine goes, it still has the bog standard Villiers carb on it. I suspect the Tilbrook head is the sum total of the ‘comp’ tuning.
Parts are dead easy, everything for the engine is available off the shelf, the headlight is a generic VEC /Miller jobbie, a Bantam saddle and tail light assembly will drop straight on and mudguards are available from WA. And of course the exhaust system as shown on the Powerhouse example is straight James ML readily available of eBay. Parts are absolutely no problem.
Painting, plating and tyres, etc, are a different story. The cost involved are little different from doing the same on much more fancied machinery. Just because it’s a lightweight doesn’t reduce labour prices.
Good luck to the seller, he tells a good story but its still just a noisy chook chaser as it stands.

12
British Bikes / Re: Ariel Arrow Flasher?
« on: May 19, 2025, 05:41:00 AM »
I wouldn’t be surprised if they used the same harness for both.
It could’ve been more practical to just have one harness for both versions. Have two harnesses and you can guarantee mistakes sooner or later at every level of the game from the factory stock room to the dealers store to the owner ordering the wrong one anyway. They probably would have done some sort of cost/benefit analysis and concluded a one size fits all was cheaper and less hassle in the long run so went that way.
We’ll probably never know.

13
Identify these bikes! / Re: Villiers stationairy engine
« on: May 14, 2025, 12:52:47 PM »
As you remark Leon, placing trust in auction house puffery is moving on to shaky ground. Even the auction houses warn you against it.
So far as engine swaps are concerned a major virtue of Villiers engine was they didn’t change from year to year so you could safely exchange engines without worry plus of course for years Villiers powered bikes were so poorly regarded that it made more sense to replace a worn out engine with another less worn secondhand one than actually spend money refurbishing one. After donkeys years of these old bangers being mauled about its bizarre that we should expect the numbers to match up.
As you say, it’s only the ones with an established provenance that make sense. Provenance is all.

14
Identify these bikes! / Re: Villiers stationairy engine
« on: May 14, 2025, 02:23:36 AM »
Villiers would add an extra letter to the engine prefix for various reasons, not all of which I yet know but no matter what the underlying engine remains the same.
I do know the extra ‘F’ refers to FIXED ignition. Previously Villiers had clamped the magneto backplate onto the protruding main bearing bush. Slackening off the clamping screw allowed moving the backing plate back and forth to get the ignition timing just so. Villiers even fitted an advance and retard lever to the backplate to facilitate this. It didn’t work. Getting the clamping force just right, loose enough to move but tight enough to stay put otherwise was nigh impossible. Some factories fitted some sort of device to hold the lever in place but these have mostly disappeared over the years.
The idea of slackening off the clamping screw to tweak the ignition just so remains a good one, just make sure you tighten it up again afterwards.
In the end Villiers not only dropped the idea but went further and mounted the backplate permanently in a fixed position, hence the additional ‘F’.
This came late in the XII-C’s life. The earliest engine number I have is GYF 10421, first registered in May 1939.

15
Identify these bikes! / Re: Villiers stationairy engine
« on: May 13, 2025, 03:41:44 AM »
In broad terms an alloy Villiers piston is 1/3 the weight of its cast iron equivalent. Thus the engine runs more smoothly as there is so much less weight moving up and down the cylinder. Further to this it takes much less power to move the lighter piston in the same fashion so the extra power required to move the heavy cast iron piston is now available for the rider to take advantage of. Finally the alloy piston disperses heat better than cast iron so the engine can be worked a little harder with no detriment.

So the upshot is the same engine with an alloy piston runs more smoothly, revs more willingly, is a little nippier and stays a little cooler.

Cast iron has its virtues. Given care a cast iron piston will last indefinitely running in a cast iron cylinder. It is easy to work and requires little if any heat treatment. It is also cheap. In some circumstances an operator may value these virtues above those offered by an alloy piston.




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