AJS & Matchless Owners Club

East Suffolk Section

Richard C’s 1951 Matchless G9 500cc Twin

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.
G9 aOptimism 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!!