A brief flirtation with a 7R
The single overhead camshaft 7R AJS was known as the Boy’s Racer – a production racing motorcycle the lads could afford and tune. It was the mainstay of the 350cc class from its introduction in 1948 to the mid 1960s.
In 1959 I bought a second-hand 1951 AJS 7R for 100 quid from Laurie Jamieson in South Australia. I didn’t enquire about its previous history. In retrospect I wish I had. Not that there was anything wrong with the bike. We push-started it in Laurie’s driveway and it had that wonderfully rich cammy sound, so I happily handed over the folding stuff and proudly drove home with a 7R in my trailer. My first race with it was at the Port Wakefield circuit north of Adelaide. Prior to this a couple of mates and I took it to a long stretch of straight bitumen for a fuel mixture test, checking that the plug was the right shade of grey. I lived at Tanunda in the Barossa Valley. The nearest piece of tarmac with relatively little traffic was located at the foot of Accommodation Hill, heading from Truro to Blanchtown. This was flat mallee country. We used to do the testing soon after day-break on a Sunday morning, when there was little chance of traffic, and hopefully even less chance of the cop at Truro turning up, who had a wide-spread reputation for being particularly diligent. He did eventually ping me, but that’s another story. The memories are priceless. What a pleasure it was, on a cool pristine morning, to take in a few lungs full of the dew-soaked aroma drifting in from the surrounding mallee saltbush – soon to be trumped by the even more exotic redolence of a few good sniffs of BP Racing Fuel as we carefully poured it from a 4 gallon drum into the 7R tank via a funnel. Even more priceless are the memories of the push-start. The patter of 6 or 7 quick steps and then rrrrrrrRRRRRRMMMMMM – the air-cracking burble of a 7R being warmed up. Followed a few seconds later by a chorus of magpies and crows from the surrounding bush complaining loudly about having had their sleep disturbed so early on a Sunday morning. And the colour of the plug? Just the right shade of grey. We went through this same ritual test run of the 7R before each race meeting. There was no mechanical reason for the test. We hadn’t done anything significant to the engine that might have required a different jet. I think we did it mainly for the sheer pleasure of listening to the 7R in the Australian bush on a cold Sunday morning.