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Technical Tips


by Colin Flannery

Way back in the mists of time I was a spotty apprentice at a Buckinghamshire garage that sold Cyclemasters and of course the early machines did not have a dismantleable silencer system.  We had a way of de-carbonising which was a 100% efficient and lots of fun too ... it works well with a steel exhaust system that is not plated.  An oxyacetylene welding torch with a No 3 nozzle is lit and placed in the top end, whereupon the carbon deposits will glow.  The acetylene is then turned off and the burning carbon front will advance, being fed by oxygen alone, the progress of the burning being monitored by watching the dull red area of the exhaust.

Smoke will pour out the end as the oily deposits are removed and there may be an occasional bang as gases ignite at the flame front, so it's best to do it outside.  Ideally send the Missus out and keep upstream of the smoke to avoid smelling like a kipper.

First published - April 1997

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Hints & Tips for Cyclemasters

retrieved from "Magic Wheel" magazines by Roger Worton

Holes in Cyclemasters

  1. The term "drying up" is given to the sort of engine failure which is caused by the shortage of fuel.  Blockage of the filler cap vent hole (by excessive polishing - polish - or by under-excessive polishing - grease & dirt) will cause an air lock in the tank.  Much more noticeable when the tank is full.
  2. The small hole in the bottom of the "CM" cover is there for a purpose.  The magneto needs air just like we do.  Without it condensation and burning of the points may be caused.  The hole also reduces any tendency for condensation caused by the intermittent heating and cooling of the surrounding metal.
  3. There is an 1/8" diameter vent hole in the aluminium casting immediately behind the cylinder base, just in front of the rear suspension bolt.  Its purpose is to release pressure inside the clutch housing when the engine gets hot.  If this hole get blocked, oil may be forced through into the magneto area.
  4. Any air leak into the inlet pipe between the carburettor and the crankcase will upset the mixture and consequently cause bad performance or difficult starting.  Make sure the inlet pipe flange gasket is sound and the two securing screws are tight.  Make sure the carburettor body is pushed onto the inlet pipe as far as it will go or air will be drawn into the mixture through the slots in the carburettor body.
  5. The Bantamag has three holes in the flywheel and owners of the Cyclemaster ask which one of the three should they use for setting the points.  Two of the holes have setting instructions, but one has the mystic letters "CW" and the other "CCW". These letters simply mean ClockWise and Counter-ClockWise.  The crankshaft of the Cyclemaster revolves counter-clockwise so that is the hole to use when setting the points.  "Why have two sets of instructions then?" I hear you ask!  The answer is that the Bantamag was fitted to several other engines and some went round the other way.  This point does not arise with the Series 90 magneto fitted to wheels from no 76751.

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Modernisation of Villiers ignition electrics

by John Harrison

  1. Remove the insulation and all the original wire (both thick and thin) from the coil former.  Unsolder the beginning of the thick wire from the metal of the coil body.
  2. Using 20swg enamelled copper wire, solder onto the original soldered earth connection and wind approximately 180 turns onto the coil body; try to finish at the termination end.  Scrape off the enamel and connect to the hole in the side, screwing down the grub screw to make a connection. 
  3. The HT (High Tension) is now produced using a Honda 50 (AC) type coil. The new coil is earthed and connected to the points along with the output of the coil you have wound. 
  4. I suggest that when you have got the system working you remove the LT coil and encase the windings in Epoxy resin to protect them from mechanical vibrations.

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How to make Cyclaid drive belt rims

John G Hughes

The dearth of Cyclaid belt rims and recent advertisements hunting for them, have prompted me to explain how I made mine.

Although the original rim was made of steel, I decided to make one out of copper first, as this metal is easily wrought, and then go on to make a steel one with the knowledge and skills I had learnt.  In fact, the copper rim (painted black) works so well I have not yet bothered to make one of steel!

The first thing required is a wooden disc 12¾" in diameter. ¾" blockboard or chipboard is ideal.  You will need about 50" of ½" copper water pipe.  This is first annealed by bringing it to red heat and then quenching in cold water.  Copper in this state will bend easily around the disc, but do beg or borrow a plumber's bending spring to stop the tube from flattening.  Allow the ends to curve past one another by 6" or so, to ensure they describe a true curve where they will meet.

Using a fine tooth saw, cut through both pipes where they pass.  Gently pull the two cut ends into alignment.  It is probably a good idea to anneal the copper again here.  I didn't, in the belief that the work hardened metal should be better able to resist the engine's forces.  But later on the copper was hard to work.

The next stage is to silver solder the ends together.  You may find that some sort of clamp is necessary; I was lucky, the two ends stayed perfectly in place during soldering.  Silver solder is the amateur engineer's 'dream glue'; it will allow you to fabricate almost anything, with a strength not far short of steel.  (For those not familiar with it may I recommend: "Soldering and Brazing" by Tubal Cain, Argus Books Ltd?)

You should now have a continuous circle of tube of 12¾" inches internal diameter.  The problem now is to cut right round the outer edge of the tube, just off centre.

I did this with a 14" hacksaw - it wasn't easy!  It may be easier for people with access to a big enough lathe, to mount the tube on its wooden former, and pierce it with a narrow tool.

Next, keeping it true on the wooden disc, open out the cut.  First with a screwdriver, then pliers when you can get them in the gap.  Work around the rim a bit at a time, don't try to open up too much in one place.  Finish off the long side with a hammer on a flat surface.  You now have a J-section ring.  Again with pliers and a little at a time, turn the short edge outwards and, after inserting a bit of ½" bar or rod in the channel, hammer this edge down.

The rim should work and transmit the power in this basic form, but a few refinements are advisable.  From about 6" of 1¼" × 1¼" hardwood I made a male and female shape of the required V-section.  After putting one half in the vice, I worked round and round the rim with hammer blows on the other half former.  It wasn't very successful!  Steel blocks would have worked much better.  However, after squeezing around the inner edges with a Mole wrench and a lot more hammering with the blocks, the result was quite acceptable.  Remember that, on a pulley of this size, the belt contact area does not have to be perfect to have a much larger grip than the little engine pulley has.

Lastly, because copper is softer and more easily deformed than steel, I soft soldered strips of brass to reinforce the back of the rim where it is bolted to the spokes.  Short lengths of alloy strip (about 3/4" × 3/8" × 1/8"), drilled and tapped 4BA, behind each spoke complete the operation and you are now ready to spend even more time than you did making it, in trying to get it central and running true on your wheel.

Paint the rim black; shiny copper would look wrong - and give the game away!

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Cyclemaster parts

by Keith Walker

My local bearing stockist informs me that:

Most bearing suppliers will give you 40% - 50% discount if you ask for it.

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Mini-Motor Restorations

by Derek Rayner

As with all small two stroke motors, it is recommended that during restoration and renovation, as well as attention to the magneto and compression, the oil seals and bearings are also changed.  Due to the technicalities of the two stroke engine and the 'sump' acting as a pressure vessel, it is necessary for the 'sump' to be gas tight.  Crankcase seals therefore are most important in this respect.

To help fellow Mini-Motor owners, since ours has recently received the bearing/bush treatment after the Stowmarket run on which it performed less than satisfactorily (it now performs admirably), the following are the items obtained from our local dealers (Bearing Services Ltd - but Edmunds Walker are probably just as good and I am sure there are other similar places).

Total cost about £20 - for a world of difference.

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How to apply varnish fixing transfers

  1. Separate the backing paper from the retaining tissue just at one corner of the transfer. 
  2. Lightly and evenly coat the printed area on the back of the transfer with varnish. Avoid polyurethane varnishes as these will attack some transfers, Raleigh recommends "Copal" varnish for its cycle transfers.  When the varnish is extremely tacky (after 10 - 15 minutes) the transfer is ready to apply. 
  3. With the aid of the guide lines printed on the backing paper, position the transfer on the machine.  Press down lightly.  Now carefully remove the backing paper starting from the corner you separated at the beginning.  Then press down harder, removing any air bubbles. 
  4. Using a piece of soft material (eg cotton wool) soaked in water, saturate the tissue until it slides off or disintegrates. 
  5. Any excess varnish can be removed using another piece of soft material dabbed in white spirit.  Dry off the surplus spirit with a dry piece of soft material. 
  6. Allow the transfer to dry for at least 24 hours before handling it.  A final coat of varnish over the transfer will help to protect it. 

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