The following are a collection of new items that may help you to overcome old problems. These items have been featured in Jampot the monthly AJS and Matchless Owners Club magazine. Join the club now!

Modifications

Twin Primary Belt Drive
This feature in September 1997 issue of Jampot ran to five pages of detailed information concerning the modification of an alternator twin engine to primary belt drive. When the modification was complete the only externally visible differences were a 1/4" thick spacer between the two halves of the alloy primary chaincase and a breather pipe running from the back of the timing chest up to the oil tank. The new 6 spring four plate clutch, front pulley and 25mm belt have to be run dry which necessitates blocking off the normal engine breather and making alternative arrangements. The clutch which fits straight onto a standard AMC gearbox mainshaft has 68 teeth whilst the front pulley has 36 teeth. Minor modification to the inside of the alloy chaincase was required to ensure that there was no fouling of the new assembly.
The clutch, belt and front pulley was supplied by Bob Newby Racing www.bobnewbyracing.co.uk

Magneto Timing for Singles
This feature in July 1998 issue of Jampot described a lower mag drive sprocket which could be simply adjusted to give 2.5 degree increments to the timing. This lower sprocket consists of a sprocket with 12 holes, the rear flange with 13 holes, a large washer with a locating pin and a nut to hold the assembly together. To adjust the timing simply remove the nut and the large washer rotate the sprocket in the required direction and the relocate the washer/pin and tighten the nut. No more fighting with the top sprocket on the tapered shaft of the mag!

Other articles that members have submitted over the years have helped to solve the following problems:
1.  How to torque down Twin head nuts. This is not as easy as it sounds due to recessed seat on the head.
2.  How to sleeve a badly scored oil pump for a heavyweight single.
3.  How to modify the Stop Light switch bracket for a Model 31
4.  How to modify engine mounting plate to get a decent clutch cable run for CP Gearboxes.
5.  How to modify a standard heavyweight road frame into a trials frame.
6.  How to hold a centre stand spring in the bound mode for easy fitting.
7.  How to avoid rear wheel wind up on full width alloy hubs. Its a pity I had to experience this before the article appeared.
8.  How to fit a crankshaft oil seal to the inner alloy chaincase of a twin.
9.  How to fault find/modify mag and coil ignition systems.

If you are not receiving the Jampot you are missing out on many years of accumulated knowledge plus the opportunity to write in with either your own problems or solutions to problems that you have overcome.

How will you manage when Leaded Petrol is no longer available?

From January 1st 2000 leaded petrol as we know it will no longer be available in the UK. Lead Replacement Petrol will be available until 2003 but will not be sold by all garages. Various additives have been available for a number of years which claim to overcome this problem but until recently no recognised research body had tested these products.

The Federation of British Historic Vehicle Clubs (FBHVC) is now endorsing four Lead substitute products as being adequate for normal driving. Twelve out of the forty or so manufacturers that make such additives put forward their products for extensive testing by the Motor Industry Research Association (MIRA).

Each product completed a 70 hour test programme including a 20 hour period of accelerated wear testing at full throttle and full load. Tests were also conducted with normal leaded, unleaded and low-lead petrol for reference purposes. The four products that passed this rigorous testing are:

These products must be used at every re-fuelling and used strictly in accordance with the manufacturers instructions. They must not be mixed, once a product has been chosen stick with it. These Valve Seat Recession products must not be used in any vehicle fitted with an exhaust catalyst.