"The Arcanum build began when I picked up a ‘78 Yamaha SR500 from a guy in Newcastle, it was an Australian complianced and delivered bike and came with a second Aussie complied frame. The SR was sold as a “non-running, hasn't been started in 10 years bike” so I knew I'd have my work cut out for me, but it did allow me to get it cheap."
"I've always loved the quirkiness that An-Bu Custom Motors has brought to the Japanese custom scene, and I'd had my eye on their fairings and seats for a number of years, so I placed my order and prayed the fairing and seat would arrive without damage. Every single part came off and I rebuilt the bike in stock form into its matching numbered frame. Obviously the bike was still a non-running bike so the first week was spent digging chunks of old fuel out of the carby, replacing the battery, checking compression and releasing its seized clutch. The SR runs a dry sump with the oil in the frame and I found loads of thick gelatinous oil deposits, blocking the oil pump feeds, returns and filters; it was a mess. However, at the end of that week, the bike fired up in a flurry of black and blue smoke as leaves and crud shot out the exhaust. A couple of laps around the block confirmed the clutch was almost gone, slipping at anything over 2500rpm and the steering head bearings and brakes were highly suspect."
"With 8 weeks until Throttle Roll the build started. The fairing, tank cover and seat had arrived and there were plenty of rough edges to sort out, but first was to strip enough of the stock bike back to mock everything up. The tank cover is a cool trick. It's made by Posh and fits over the stock tank of a late model SR400, so a suitable late model tank was sourced. The tank cover is about 2inches longer than the stock tank, so the seat mounts and a tail loop were fabricated first to ensure everything would fit. The hardest part was knowing that in the less than 8 weeks I had left I had to line up suppliers (sandblast, powdercoater and paint) to ensure that everything would return in time for the next stage, but I couldn't send anything out until I had a solid mock up to fabricate everything I needed."
"I had intended to bore it to 535cc and port and polish, but time was against me and I'd managed to get it running really strong with great compression anyway. As they say, “if it ain't broke, don't fix it” so the top end was left alone. The engine was cleaned up and painted whilst bolting on a Keihin FCR39 for the extra horses. Ohlins at the rear and Ikon front springs with fully rebuilt forks, tapered steering head bearings, wheel bearings, rebuilt master cylinders, rebuilt callipers with braided brake lines, new slotted discs, a brand new reproduction wiring loom, modified for the Daytona Verona digital gauges with a smaller gel battery and all electrics sitting in the fabricated tray beneath the seat which was welded rather than bolted in.
With 24 hours to go until delivery to the show, I was still tweaking and checking. I haven't had it on the dyno yet, but I expect it will exceed my last 500 which was putting out 35Hp and ran a 14sec quarter mile, so I can't wait to get it fine tuned and give Arcanum a run down the track."
For the full length feature story and more amazing shots of the Arcanum grab a copy of Tank Moto issue 5 now.
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