Dave’s Yamaha WR450 Malle Mile bike
This amazing Yamaha special turned out to be one of the biggest headaches I’ve ever worked on. That’s no reflection of builder and owner Dave, whose work is amazing. I just couldn’t get the damn thing to spark! I am grateful for his patience while we tried several possible solutions.
In the end it turned out to be simple bad luck. The original Yamaha CDI unit, which had worked fine before the loom build, was dead. According to CDI specialists Rex’s Speedshop, old units can go pop when confronted with healthy voltage for the first time in a long time. An Ignitech replacement was the answer – as it so often is.
The bike itself is extraordinary. The WR450 motor sits in a modified Yamaha XS500 frame with a custom oil tank, Öhlins forks and shocks, hand-made mudguards and number boards, a vintage Yamaha tank (probably a DT series) and a one-off high-level exhaust. Electricals: LED warning lights and tail light, M-Blaze indicators, aftermarket headlight. The lithium battery sits in a heat resistant 3D printed box.
The stock WR charging system isn’t suitable for a lithium battery so we got Rex’s Speedshop to rewind the stator. Alongside a MOSFET regulator rectifier we hope it will be enough to make the battery behave. There just isn’t room for a traditional battery with enough guts to turn the starter over.
With all the delays, Dave couldn’t get the bike ready for this year’s Malle Mile, but it should be there in 2022. I can’t wait to see it.