1972 Yamaha YR5
I’ve owned this YR5 since 2005 and had it on the road since 2007. It was always destined to be a bit non-standard as I had to cut the original cylinders off with a grinder and use RD ones. I ran it in mildly modified trim (jetting/allspeeds) until the end of 2016 when I decided to reverse the gentle cosmetic deterioration of the years and also make it into something more suitable for trackdays.
Main mods are tuned cylinders, RD250B cases and gearbox, Vito crankshaft, 28mm Mikuni racing carbs, Powerdynamo generator with Zeeltronic programmable DC ignition, JL pipes and HVC rearsets.
I finished the main build in summer 2017 and managed to run it in, get it dyno tested (a very reasonable 51bhp at the wheel) and get out for a trackday at Cadwell which proved the concept.
However, it also showed some flaws so I’ve been sorting these over winter. I used RD cases to solve the issue of crank seals blowing out and allow the use of a closeratio six-speed gearbox and did a few other minor bits like fitting a better clock set-up. She’s back together and just needs gearing to suit the new gearbox. Fingers crossed she’ll be spot on now.
“IT WAS ALWAYS DESTINED TO BE NON-STANDARD – I HAD TO CUT OFF THE ORIGINAL CYLINDERS “