Smoking days gone by
The RD500LC was the first of its kind, borne out of an exceedingly short lived period when a small, and intimate, group of mid capacity two-strokes supposedly mimicked the world of the GP racer.
Before this brief period of two-stroke nirvana, we had a decade and a half of limp, but none the less exciting to ride on the road, two-stroke twins and triples. These all featured simple, yet staggeringly effective, technology but, were all styled along the lines of the roadster with no fairings and other trappings fitted as standard. As such, the RD500, along with the Suzuki RG and Honda NS that followed, is a breed of machine unlikely to ever be seen again with few bed fellows to share garage space with. The sight of many separate exhaust pipes belching out the blue haze so loved by the two stroke fan yet hated by the greenies and emission regulators, needless to say who won that battle. A quarter century or so later and the RD500 is still there at the top of most people wish list, maybe not to actually own one, that would be to labour and financially intensive but certainly to have a ride on a bike that was so closely styled and modelled after the real thing.
There can be few motorcycle experiences better than a two stroke when it raises its game and lifts up onto the pipe. The sense of urgency that the exhausts display has few peers when it comes to two wheels adrenaline rushes. Even if the modern diesels out gun the RD in all areas the feeling when the needle rushes through the power band is top stuff. The look, the sound and the feel are all unique to the period but thankfully the bike does come with a few mod cons to aid day-to-day ownership. Anti dive brakes were an attempt at sorting out the excessive front-end dive under braking and to some extent this does work but not without considerable cost. The braking feels wooden, with a lot of lever travel used up in the actuating of the anti-dive system, while the front-end stiffens up way beyond what feels safe, especially under severe braking. On the plus side, the power valve system cleans itself every time the ignition is switched on, indicated by the three stage whirring noise before the engine bursts into life, while the autolube feeds the correct amount of lube into each of the four cylinders. This is the world of the kick start though, no electric boot here; the hefty alloy lever has to be folded down and out by hand before a good sharp kick has the V-four burbling away, puffs of blue smoke stuttering out of the rear end, while the whole bike shakes in anticipation of what lies ahead.
What is it like?
As GP replicas go, just because the spec sheet suggests it mimics a racer, the real world experience does not always indicate that to be the truth. Yamaha promised the biking world a real GP Racer riding experience, and we all waited with baited breath. The reality was a watered down, sanitised version of those fire breathing race machines. While King Kenny had 150 plus BHP pushing along around 140kgs, Joe Bloggs was offered a mere 90, and even then it was held down by a third more weight, still this was enough to impress most and was certainly sufficient for the public roads with its variable surface and weather conditions. Any biker who had previously ridden, or even sniffed the air following a two-stroke engines belch, was looking forward to sampling the “real deal” on the road. When the RD500LC finally arrived, the anticipation was still there, the PR mans work had been accomplished and then some. All thought that for the asking price of £2995, we were getting something that King Kenny would have been proud of.
As two strokes go the big RD is a pussycat, despite churning out decent horsepower and torque figures, the two peaking at the same time in the perfect love match. Yamaha claimed 100 plus bhp but in reality mid 80’s is more like it with many achieving way less due to poor set up of the complex engine and carburetion. Handling is in a league of its own, not due to a particular sharpness or competency, but rather a headstrong and single-minded approach shown by the V-four. Sometimes it does your beckoning; while at other times you are merely a passenger sat enjoying the ride while the bike does its own thing. The fat, 16-inch front tyre commands the show, often overriding the rider’s wishes and certainly bullying the rear end into doing its dirty work.
Forgetting going around corners for a short while, getting out of them is where the RD comes alive; get the needle anywhere above the 6000rpm mark on the tacho and the engine clears its throat, taking off with an enthusiasm unique to the world of the stroker. Each cylinder has an electronically operated, variable exhaust port, which when all four are set up in sync allows the otherwise peaky two-stroke to behave rather more like a four-stroke. Engines can be weak, with around 20k predicted before a major bottom end overhaul. This sort of work isn’t for the faint of heart as the engine has many components to contend with while the cranks themselves use many special parts and tools in the pulling apart and putting back together again. A simple thing like a leaking fuel tap can wreck the main bearings in no time at all while the top end of the engine is typically two-stroke in its fragility, so abandon all other hobbies when purchasing an RD500LC as it will take over your waking moments forever.
All of this aside however, and few would not leap at the opportunity to sample a GP race replica, even if the Suzuki RG500 is just that little bit closer to the experience and the Honda NS400R by far the most refined, if a shade slow.
Yamaha RD500LC Model history
The RD500 isn’t a true V-four, but rather two 180-degree crankshafts taken from the TZR250 and arranged so the cylinders sit 50 degrees apart. This layout requires a power-sapping balance shaft simply to iron out the sharp and high intensity vibrations as the revs build up and isn’t the ideal configuration. The closeness of the top ends to each other also leaves little room for the carburetion, the two banks of twin 26mm Mikuni’s sitting facing outwards and their the inlet tracts wind their way through 90 degrees before entering the engine. Even then things are stacked against the norm, the front pair of cylinders are fed directly into the crankcases as per a modern two stroke design while the rear pairing have a more conventional inlet system via the rear of the cylinder wall. This uneven engine design has confounded many a tuner, hopeful they could make the race rep into a real goer on the track, since the day the big Yam entered the scene. The exhaust did little to help out either, the lower two follow conventional thinking and at least look like a pair of expansion chambers but the upper set twist and meander their way out the rear of the seat, once again creating almost two completely different engine configurations even though they are firmly bolted together. Two versions were announce in 1984, the steel framed one intended for the UK and Europe and the alloy framed model, this was considerably lighter while looking virtually identical with many seeing action in the southern hemisphere in the hot bed Australian of production racing with riders like multiple world champion Mick Doohan cutting his race teeth on one. Suzuki announced their answer during the latter part of 1984, the RG500 Gamma once again styled alongside the GP race bikes but in the case of the Suzuki much more so. No punches were pulled in the design and development of the square four Suzook and it eclipsed the Yamaha in a big way when it arrived in the dealer showrooms during 1985.
For 1985, the RD500LC got an update within the engine to smooth the excessive vibrations causes by the 50-degree layout and also, a new ignition providing a shade more power in the upper reaches of the rev range. The writing was on the wall however and within the next two years the RD had disappeared from the Yamaha line up altogether.
Yamaha RD500LC Specifications
Engine – liquid-cooled 4-cylinder 2-stroke
Capacity – 499cc
Bore/stroke – 56.4 x 50mm
Power – 90bhp @ 8500 rpm
Torque – 48ft-lb @ 8500rpm
Carburation – 4 x 26mm
Transmission – 6-speed wet clutch chain final drive
Frame – square section steel tube
Suspension – 37 mm telescopic forks. Rising rate monoshock rear
Brakes – 270 mm discs 2-piston calipers. 270 mm disc 2-piston caliper
Wheels – 120/80 x 16 130/80 x 18
Weight – 178 kgs
Top speed – 135 mph
Wheelbase – 1350 mm
Fuel capacity – 22 ltrs
RD500LC Timeline
1984 RD500 LC Mk1
The first of the RD500’s, the 47X model, emerged to a stunned world.
1985 RD500LC Mk2
Several minor but no less important changes were implemented for the revised version of 1985. The balance shaft was re calibrated and was now driven via the rear crankshaft instead of the front one; this was aimed at reducing the high frequency vibration experienced once the engine was in its power band, while the upper exhaust pipes grew longer stingers on the silencers. The ignition switch sat within the top yolk casting too, making the later version instantly recognisable from a rider’s eye view.
Yamaha RD500LC Gallery
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