Most XS500s in the UK seem to be rolling wrecks. A pleasant surprise, then, to find one that was both whole and actually shone with repressed vigour! Not surprisingly, it was an import - from Japan rather than the States. The motor’s the main point of conjecture on this bike. A vertical twin with pistons moving up and down alternatively, DOHC's, eight valves and an infamous chain driven balancer system that must've inspired the Superdream's designers. This was a 1974 model, so very advanced for the day. Not their first vertical twin design - the famous XS650 made their name in the genre, although the TX750 had much more in common with the 500.
The XS500's mill has a bit of a reputation for self destruction, though a few past UMG tales indicated that it wasn't a total turkey; its 50 horses and agile chassis making for a moderately useful tool. The import had only 8500 miles on the clock, though the dealer refrained from suggesting that it was owned solely by a little old Japanese lady. The two grand price tag was a bit of a laugh, and I didn't really believe his protestations that it was a coming classic. Cash was mentioned and after some hard haggling I could have it for 1400 notes if I was willing to forgo the guarantee.
A quick blast had confirmed that the motor had plenty of poke, that the chassis still tracked true and that the engine noises, though harsh, didn't sound terminal. The deal was done there and then, I rode home as happy as a vicar in a bordello. A quick bit of speed testing revealed a top speed of 108mph, which no amount of further thrashing bettered. Acceleration was vivid with the rev counter in the 6000 to 10000 sector but below those revs the engine felt very unhappy. A combination of whirring balancer chain and the off-beat nature of the engine pulses. The mill smoothed out nicely as the power came in, though at the top end of the rev range it began to thrum through the machine a bit.
Some more on the road experimentation revealed that fuel was a poor 45mpg, the drive chain - admittedly old - needed a daily tweak and there was a disturbing tendency for the motor to clatter to a halt at tickover revs and then refuse to catch for a few desperate minutes. At this point I did the decent thing, or attempted to. Yep, the cheap engine alloy was in full rot mode. I found this out when I went to do something as simple as change the spark plugs, which had corrosion welded themselves into the cylinder head. The latter is a vastly complex piece of work, renown for burning out valves and spewing out oil once things go out of adjustment.
I was tempted to give the plug-wrench a hefty tap with my hammer, but the thought of the plugs breaking in half stopped me. After some muttering, half a can of WD40 was emptied over the plugs and left overnight. They still didn't want to budge so a short sharp tap was applied. The left-hand one twirled out as if nothing in the world was wrong but the other one creaked and groaned all the way out, taking some of the head's thread with it. The plugs looked ancient, original fare. A dab of Araldite was added on the upper thread of one of the new plugs to compensate for the depleted thread in the head. Great care needed on the plug-wrench.
The new plugs all but transformed the engine. Easier starting, better sub-6000rpm running and no more cutting out. That left me free to concentrate on the chassis. A single front disc and rear SLS drum didn't add up to major stopping, not helped along by the pads being Jap crap that were glazed with age. Fortunately, the disc and caliper were identical to early XS650s stuff, meaning parts were actually available in the UK. Even with a couple of EBC pads the braking wasn't exactly vicious but at least I had a reasonable idea of what was going to happen. Engine braking, by the way, made the motor clatter like it was falling apart.
The suspension was original fare. The forks looked very similar to the XS650's, though the 500 weighs a lot less than that venerable twin. Both the forks and shocks were weak on the springing and had little damping. A used pair of Konis were adapted to fit the back end and some stiff springs added to the front forks. That let the conventional tubular chassis do its business without the previous falling apart at speed feel. There was still a mild weave at 90mph plus speeds, traced to a slight amount of play in the swinging arm but I could live with that - given the state of most of the metal it was likely the spindle was seized in, the only way to get it out involving its destruction!
Though the general finish wasn't far off showroom condition the approach of autumn rains heralded an outburst of corrosion, the machine rotting from the inside out. Before I could deal with that the clutch began to play up. The gear change itself had always been wonderfully slick, reflecting the bike's minimal mileage and Yamaha's expertise in this area. However, with the clutch slipping at high revs and rattling at low rpm, the change became quite stiff and relatively easy to put into a false neutral. I had little choice but to whip the engine cover off. Anyone who's played with old Jap alloy will know that nothing's that easy...
I actually had to drill a couple of the corroded screws out! A first for me, the old hammer and chisel routine had always sufficed in the past even when the impact driver failed. I didn't completely ruin any threads but what should've taken half an hour actually ended up consuming a whole weekend. All that effort was rewarded with the realisation that the clutch's bearing was shot, which had in turn done for the plates! It took two weeks of phone calls to locate someone who had broken an XS500 - the reward was a good clutch unit for a fiver! When you can find them, parts are ridiculously cheap because there are so few XS500s left rolling on the road.
As to the chassis, by the time winter had turned to spring there wasn't much paint left on the frame and even the tank was bruised with rust! An amazingly rapid degradation, which I patched up without taking the bike tight down to its component parts. On the good side, the valves never needed any adjustment, the carbs required a balance once and the engine thrived on frequent, 1000 mile, oil changes. The clock was reading 14400 miles by the time March turned into April and the roads were ready for some serious mileage.
At this point, the amazingly uncomfortable seat decided to fall apart and the front bars started acting weirdly. The latter down to the front wheel bearings dying a death. Easy enough to replace via the bearing factors but a pain nevertheless, making me realise I was on a bike that was self-destructing as I rode it along. The usual complaints and praise about XS500s - poor engine life and good chassis - appeared reversed on my particular example.
By 16000 miles I decided enough was enough and it was time to get shot of the bike whilst there was still a whole machine left to sell. 1200 notes in the advert, I was happy enough to settle for 900 quid. The new owner had a garage full of defunct XSs. No accounting for love, is there?
Duncan Hughes