I have heard that confession is good for the soul. It seems that a few of us have years of guilt to cast off.
My first bike was a 1957 BSA A7. I was a 17yo farm boy in 1968 and just finishing High School, no licence and I had to get my older brother to ride it home. It blew a cylinder base gasket on the way home. So before I had ridden it, I stripped the top end down. My only previous experience was dismantling a 1946 BSA C10 when I was 15, new rings and re-assemble.
Neither Dad nor brother had any mechanical skills, so I was on my own
. The small end bushes were knackered, so I replaced them myself using a bolt and washers etc. The gudgeon pins would not fit, so I had to open the small end bushes a little didn't I? Having no mechanical tools or experience, I found a round rat-tail file in Dad's farm shed. Now that did the trick thought I. I later told a workmate about the rat-tail file and he said "You did what???"
Not long after, a persistent rattle demanded another strip down.
By this time my confidence had become enormous
, so I ventured into the bottom end. I felt lots of movement in the Timing Side, so bought a new T/S bush, heated up the case and dropped it in. What a great job thought I.! Gee I was a real motorcycle mechanic!!! I got new cam-ground high-compression pistons and had someone else replace the small end bushes.
Knowing nothing about line-reaming or end-float, I slapped the crank back in, assembled the motor and was ready to start it.
I could not kick the thing over. I just stood on the kick starter and nothing happened. So off with the chaincase, and I turned the crank over using a Stilsen (adjustable toothed spanner) for about a half hour.
I had the sense to realise that normal oil would be too thick, and the only thing else I had access to was the farm tractor's 44-gallon drum supply of diesel fuel. I filled the oil tank with diesel. After a further hour of Stilsening, it had freed up enough to go to the next level. No spark plugs of course ( I had worked some things out)
Our farmhouse was at the bottom of a slight hill of 200 metres long. I pushed it up to the top several times, and ran the bike down until the motor turned quite freely.
Then drained the diesel, re-filled with oil and kicked it over. It started quite well. I became aware of excessive frothing in the oil tank, so had to drain and refill the oil several times until the frothing stopped. There was a bit of noise in the top end, and a seizure followed caused by the larger diameter pistons hitting the head. I had not chamfered the head to allow for the higher crowns. I filed off the excess metal from the skirts, ground a chamfer on the head and slapped it back together.
Anyway the A7 ran beautifully and reliably for another year, before a 1959 Matchless 600 twin with purple metalflake tank and aluminium guards stole my heart. It was in the window of a bike shop in Newcastle (NSW). I swapped it for the A7. The Matchy went terribly until three weeks later I discovered that it was fitted with an air slide which was in the closed position. I eventually sold that to my mate Phil (photographed). The last I remembered of the A7 was seeing it on display in the bike shop window with a large sign - "New Engine with Cam Ground pistons". I couldn't hide quickly enough
.
I hope I have moved along a little since then.
Col
