AJS & Matchless Owners Club

Technical Tip (25) Extra leverage on your nuts!

admin2 — Thu, 19 Apr 2012 18:24:13 +0000

In an emergency on the road when your only tools are what you have with you, for extra leverage to free a stubborn nut, fit the jaws of another open-ended spanner into the other end of the one you’re using, but be careful and watch your knuckles!

Richard C’s 1951 Matchless G9 500cc Twin

admin2 — Sun, 25 Mar 2012 16:41:20 +0000

I bought this bike nine years ago off a well known Suffolk dealer and fell in love with it because it looked so beautiful. I had been looking for an early twin in good condition and this one seemed to fit the bill perfectly, and the price was good as well so I treated myself! Over the years I’ve owned her this bike has covered a lot of miles and a lot of rallies, club runs and so on, but not without incident. I soon discovered that the “full restoration” she had undergone was less precise than I would have wished. To be honest, the best bit was the paint, for a number of mechanical and electrical issues have cropped up over the years and investigations revealed weaknesses and inadequacies in her restoration.
Poor starting was remedied by having the magneto overhauled professionally. What a difference! The dynamo packed up and was carefully serviced with the help of a section member well-versed in things electrical. The wiring (which was mostly in one colour, why do people do that?) was sorted and crimps replaced by soldered joints; old style bullets replaced the garishly coloured modern ones and a new wiring diagram was drawn up.
All the threads in the cylinder heads have been helicoiled as they were so worn and after two years of my ownership I found that large amounts of oil were being burned by the right-hand cylinder. A local engineer equipped with the appropriate measuring tools told me that a poor, previous rebore had resulted in an egg timer-shaped bore! A rebore cured that, but the Clent Hills Jampot Rally of 2010 proved to be a disaster. The bike came with an oil tap which needs to be turned on before starting up and turned off to reduce wet sumping. Following the Sunday rally run lunch stop I set off only to break down with complete loss of power, needing the breakdown service’s assistance. Back at the rally site a glance down revealed the oil tap in the “off” position!!! The engine seizure, however, proved to be very minor and swift clutch grabbing by yours truly had minimised the bad effects. Inspection showed no bore damage and minimal piston scoring (I suspect the oil tap is letting a fair amount seep through). Damage was rectified and in 2011 the Bishop Auckland rally beckoned. The old girl had been riding well (up until then) so I felt confident.
Optimism is often misplaced and the rally runs were exacting, over those northern hills. My G9 became a G4.5 firing on the right-hand cylinder regularly and the left-hand one intermittently. Subsequent investigation revealed a recessed exhaust valve that had hammered itself into the cylinder head. The valve seat was loose, as was the guide. The piston was looking sorry. So was I.
All is now put right, however. Expensive machining plus lots of expensive, new bits have got her back going again, although she does require running in, and we are once more on the road, but at a sedate pace for a while. The paint still looks pretty good though and with a new kick-start rubber she’s a treat, so there’s no stopping us this year!!

Technical Tip (24) Scrub your parts with confidence!

admin2 — Sun, 25 Mar 2012 16:14:27 +0000

Without a powered parts washing machine, the workplace can easily get awash when you need to wash grimy parts clean with turps , Gunk or whatever other solvent you favour,

A plastic potting tray from a garden centre is the solution. They are about 2 feet square, sturdy and leakproof with raised sides and it will keep the mess contained whilst you clean the parts you’re dealing with. It can then easily be stored on its edge out of the way till next time.

Technical Tip (23) Improved brake switch bracket

admin2 — Sat, 18 Feb 2012 12:05:32 +0000

The heavyweight bikes ’55 to ’61 were supplied with the brake light switch mounted on a bracket that sits on the rear wheel spindle, clamped in place by the spindle nut. Unfortunately, as soon as this nut is loosened, for adjustment of chain wear, for instance, the spring on the switch moves the bracket and positioning is lost
Solve this problem with a small screw fitted through the bracket to rest on the bottom of the spindle slot in the swinging arm and stop it moving. To allow the spindle nut to seat properly, the screw head must then be cut off flush and the screw riveted over lightly to stop it coming loose

Technical Tip (22) Dealing with new dynamo brushes

admin2 — Mon, 16 Jan 2012 17:40:08 +0000

Bedding New Dynamo brushes

After fitting new brushes to your dynamo, before the cover is fitted, start the engine and then, whilst you let it tick over for a few minutes, just press gently on the brushes to help them bed in and make the best contact

Technical Tip (21) Spark plug threads in cylinder head

admin2 — Fri, 23 Dec 2011 11:57:35 +0000

A simple tool for the maintenance and repair of cylinder head plug threads can be quickly made out of an old spark plug. Carefully file four “V” grooves up the length of the threaded part with the Vees angled slightly to the left to give cutting edges to the grooves.
Heat up and quench to harden the new “plug tap” and it can happily live in your tool box until it’s needed.

Technical Tip (20) Dating a Post-War Burman Gearbox

admin2 — Thu, 24 Nov 2011 20:49:55 +0000

If you are viewing a basket-case or need to check whether a bike all started life together, it is useful to know that all Burman boxes carry a date identification.
Before 1952, the stamping for boxes starts with “G”. The later B52 boxes after 1952 start with “GB” .
The following number stamped on the box indicates the year it was built and the letter shows the month. Remember, though, production of the following year’s models always started after Plumstead’s summer holiday break, so a 1954 model could get a September ‘53 box
To check which model a box was originally fitted to, refer to Christian’s Archives-“Burman Transmission” (via LINKS)

Technical Tip (19) Greasing single-sided hubs easily

admin2 — Wed, 19 Oct 2011 11:00:20 +0000

Greasing single sided hubs easily

The grease nipples on these hubs are awkwardly placed just where you can’t easily get a straight push on a grease gun.
Take a length of wood of the right size to fit between the spokes and cut a recess halfway along its length to locate the cap end of the gun. Place the nozzle of the grease gun on the greasing point and slip the wood into place.
By pressing both ends of the wood, greasing is accurately done with no messy loss of grease

Technical Tip (18) Replacing Early Twin Cylinder Heads

admin2 — Sun, 25 Sep 2011 10:09:40 +0000

1. Put engine into high gear so as to use the rear wheel for turning the engine.

2. Right-hand cylinder: turn engine to compression t.d.c. (inlet pushrod has just gone down and piston is at t.d.c.); fit head, taking care to ensure rockers are in the pushrod cups; finger tighten the cylinder head nuts (with spacers and washers underneath!)

3. Turn engine forward so that left-hand piston is at compression t.d.c. and proceed as above. This ensures minimum strain on head nuts that would have occurred if tightened against valve spring pressure.

4. Fit manifold and fully tighten manifold nuts

5. Working in a diagonal pattern torque cylinder head nuts to 22 foot pounds

When the bike is fully re-assembled start engine and run until warmed up but not too hot. Re-torque nuts to 22 foot pounds. Leave engine to cool over night. Gently ride bike for 100 miles then torque down the nuts again to 22 foot pounds. Final re-torque after 500 miles.

Technical Tip (17) Improve You(r) Dipswitch!

admin2 — Fri, 26 Aug 2011 19:24:08 +0000

The motorcycle dipswitch is a cheap and crude device and there’s always the risk of the rider fumbling and being accidentally left in the dark, so when converting to brighter 12v lighting, fit the same reliable method of headlamp dipping used on motorcars. A small relay, called a latching relay, is required and will easily fit in the headlamp shell. One beam or the other is always connected and switching is by a push button on the handlebar. A vehicle electrician will help you identify the part you need and wiring is straightforward. (Mine came off a VW in a scrapyard.!)