Most UMG stories on the Yamaha SR500 are full of mechanical horrors and even mention many chassis problems. I have owned my 1980 example from new and have done to date 62738 miles. The bike is still on the original piston, bore, crankshaft, camshaft and gearbox. I did put in a new set of piston rings at 38000 miles, when I took the opportunity to re-seat the valves, fit new rockers and a camchain.
The engine was ridiculously easy to work on, apart from a few bolts that stripped their threads and had to be helicoiled. I put the good shape of the engine down to two things. I changed the oil every 750 miles and live out in the country, so the minimum journey I do on the SR is 8 miles. I also do a proper engine service every time I change the oil, again very straightforward.
The chassis, I must admit, did start to decay alarmingly after the first five years, despite the large amount of tender loving car expended on it each weekend. In six months she was in a terrible state, shedding chrome and paint like there was no tomorrow. Over that winter I took her down to the frame, blasted off all the crud and had most of the cycle parts nylon coated. As I had already fitted rubber gaiters to the forks they were saved from the usual pitting.
The refurbished chassis has not shown any signs of a repeat performance. The same could not be said for things like wheel bearings (every 9000 miles) or swinging arm bearings (every 6500 miles). The steering head bearings do about 18000 miles. When any of these bearings exhibit the slightest sign of wear the chassis throws a massive wobbly. You either fix it fast or end up being scraped off the tarmac. Why they should suffer such short bearing life, even when I regularly grease them up, doesn’t make any sense to me. But there you go.
The engine is not very powerful. Even if it were able to rev high and fast, the vibes once past 6000rpm would dissuade you from such indulgence. I rarely cruised the bike above 75mph, although I have had the ton on the clock on a few occasions. As I don’t like motorways this is no great loss. Vibration is present at most revs, but in the lower range is the sort of background buzz that lets you know the engine is working whilst not causing bits to fall off or fracture.
Unfortunately, the engine does not have the great gobs of torque associated with big British singles and really needs 5000rpm or above to motor. This effectively gives a 1000rpm power band if reasonable acceleration is needed. The motor will run down to 35mph in fifth if you've a mind to, but pulls extremely slowly from there on. Opening the throttle rapidly just gasses the motor up.
One curious aspect of the SR motor is its two stroke like need for spark plugs. You know when one is needed because it'll refuse to start. The engine needs a big lunge on the kickstart at the best of times. I've never managed a first kick start from cold. Sometimes it’ll fire up on the second kick, other times on the 22nd. It can be exhausting. If any component in the induction or ignition system is not up to scratch it will refuse to start until that component is rectified or replaced. Starting on a hot engine is usually a first kick affair.
Starting became really difficult after the fourth year. I replaced just about everything I could think of, trying to trace an intermittent fault. I had noticed that after I banged the bars in sheer frustration a few times the motor would suddenly agree to fire up once prodded. This led me to examine the kill switch, which was all corroded and evidently shorting out in some manner. Once this was removed from the circuit starting went back to normality.
Batteries were another source of irritation. Cheap ones lasted for less than six months, expensive ones for 12 to 18 months. I tried extra layers of rubber mounting but it did not aid longevity. A new regulator and rectifier unit off a Honda helped for a while until it exploded into flames. I put on the old components, deciding that poor battery life was a better bet than setting fire to the Yamaha. I suffered none of the ignition problems that have been reported on this model, perhaps because I never rode the bike for long in the heavy vibration sector.
The biggest fault with the bike was the front disc brake. I must admit I am used to drum brakes and biased in their favour. I actually expect brakes to last for 15 to 20000 miles before needing any attention other than the odd bit of adjustment. Imagine my horror, then, when I discovered that the SR’s caliper was prone to seizure every 4500 miles and that even when in good fettle didn't want to work in the wet. Even in the dry, the brake was only just capable of pulling up the SR from the modest speeds I employed.
I thought I had the solution when an acquaintance blew up an XBR500 (at a mere 34000 miles). I put on his front end. For a few months I enjoyed brilliant stopping power, plenty of feel and it worked as well as the best drum in the wet. It soon started making weird twanging noises which turned out to be the disc rapidly thinning down to an unacceptable level. How ridiculous can you get? I was forced to put the old SR front end back on. What a let down!
Even with the poor brakes, I never fell off the SR. I ride in a restrained manner, always aware of what is going on around me. I have been doing this for the past thirty years to good effect and much inner enjoyment. I found the Yamaha, once the suspension was suitably modified, to be a taut little runabout with the kind of sure-footed feel that will readily be familiar to any owner of a British middleweight.
This is complemented by my choice of tyres, Avon Venoms, which are cheap, last well (12000 to 14500 miles) and grip the road with a reassuring tenacity. In a similar British vein the bike now sports a neat Goldie silencer, although the lack of chrome on the downpipe detracts from the overall appearance of the system.
For the first couple of years I suffered from horrendous chain wear. 5-6000 miles a throw and inconveniently frequent oiling and adjustment intervals. The back end was always awash with oil thrown off the chain. In a fit of pique I set about making my own chainguard, using an old CD175 item I happened to have laying around. I cut this up and modified it to fit the SR. Then used that as a mould for GRP. Much sanding, filling and painting later saw the emergence of a deep black full chain enclosure. The engine breather was directed into the case, so I never had to worry about oiling.
All this hard work improved chain life to about 12000 miles. With the bit between my teeth, I had some sprockets made up to take an O-ring chain. That was more like it... 22000 miles! This was about the same as a cheapo British chain used to do on my Triumph 500 back in the sixties (with no chain enclosure). The big difference was that the Triumph had a huge 21 tooth gearbox sprocket where the SR had only 16 teeth. The Japanese have never been bothered by this anomaly.
The above may seem a lot of effort to go to, but it was just the kind of personal touch that can be made if you want to stick with one machine for a long time. It should pay for itself eventually. I have also modified the riding position to suit my body, with slightly higher but narrower bars and footrests relocated a few inches back from stock. With a recovered seat sporting dense foam long distance comfort is assured. I have done as much as 750 miles in a day without regretting a moment of the experience. I am no purist, so if I find, for example, a better headlamp or handlebar cluster whilst browsing in the breakers, I'm quite willing to experiment.
The SR is now suited perfectly to my needs. I realise that the engine is getting a bit long in the tooth, but were I to spend thousands on a new bike there would be so many things that I did not like about it that I would have to spend another large sum of money modifying it to my tastes. The Japanese have certainly mastered the art of building good engines and frames but they now have abandoned the practical side of motorcycling. I shall just have to hope that the SR keeps running long enough for them to get their act together.
Simon