With RZ500s becoming somewhat of a rarity, the Japanese import RZV500 makes an ideal alternative boasting a number of upgrades, and easily fixable restricted power... Words: Jeff Ware, Photography: Alexandra Cooper
I have to admit that I am a certified RZ nutter. My first road bike was an RZ250FN and I’ve had a few RZs over the years as well as RDs. Currently I have an RZ125 of all things. Rare little beast here. But one bike I’ve never owned that I have lusted after since I was 16-years-old is the mighty RZ500.
RZ500s are getting harder to come by these days but a good alternative is a Jap import RZV500, the alloy framed Japanese domestic mode – which is more readily available with low kilometres and will set you back around $15,000-$20,000 AUD.
The RZV500R features upgrades not found on the RZ500N such as the hand welded alloy frame, braided brake lines, air assisted forks with rebound adjustment, cast alloy brake and gear levers, alloy clip-ons and graphics.
The entire package weighed in at 9.1kg less the steel framed model. But sadly for the Japanese, the RZV was restricted to an underwhelming 64hp thanks to restricting the internal diameter of the exhaust pipes and with jetting. This is an easy fix…
Aside from the above changes the RZV500R is mechanically the same as the RZ500N we received here. The 50-degree V4 twin crankshaft two-stroke engine was seriously trick in its day but also overly complicated. The GP YZR500 featured rotary disc induction like the successful RG500 Suzuki.
Yamaha chose to go with reed valve induction and a YPVS powervalve system to broaden the powerband of the RZ500. The lower pair are fed through crankcase reed and the upper pair via the cylinders.
The Mikuni round side carburettors are mounted on 90º manifolds on the sides of the engine behind the fairings and have complex cabling and airbox shape. The lower expansion chambers exit normally, under the engine, but the rear cylinder pipes are complex and cross over each other to achieve tuned length then exit under the tail unit.
The dual crankshafts are geared directly to the clutch and there is a counter-balancer driven off the front crank. The gearbox in the RZ500 is a six-speed close-ratio unit with cassette-style removable gearbox and unusually the outer main bearings and a separate troichoid oil pump lubricates the gearbox. Two-stroke oil is injected via Yamaha’s Autolube system.
Chassis-wise the RZ500 is also complex. The forks on the RZV are air assisted with hydraulic anti-dive and prone to fork seal leaks. The rear shock is horizontally placed under the engine and uses the lower crankcases as a mounting point.
The front wheel is a tiny 16in and rear a huge 18in. This is because the under seat area is occupied by the YPVS servomotor, battery and rear exhausts.
1984 – 1986 YAMAHA RZV500 SPECIFICATIONS
Engine: 499cc liquid-cooled 50-degree V4 two-stroke
Claimed power: 90hp (64hp Japan RZV) (64kW)@9500rpm
Claimed torque: 50ft-lbs(65Nm)@8500rpm
Dry weight: 196kg
Fuel capacity: 22L
Chassis: Hand welded aluminium frame
Suspension: 37mm telescopic forks with anti-dive, rear preload and rebound adjustable underslung monoshock
Front brakes: Dual 267mm rotors with twin-piston callipers.