Thursday 30 December 2010

Yamaha TZR125


Young I wasn't but I still wanted a bike to buzz around on. I needed a mix of power, economy, light weight and reasonable handling. Most bikes which had more than 20 horses were either too heavy or too lacking in economy. I wandered around several dealers, turning down expensive HP offers and ignoring their laughter when I demanded good economy. The magazines were flicked through but nothing inspired. A friend of a friend's son had just passed his test (illegally!) on a derestricted TZR125. I didn't really want a stroker but it was offered for a weekend's test ride.

Most older readers have a prejudice against two-strokes. Visions of Norman Nippy's, Bantams and fragile early Japanese howlers filling their minds. It was immediately evident that the TZR was way ahead of those old horrors. Trilled into life the first mild kick of the lever, hardly any exhaust smoke. Derestricted to 22 horses, the 124cc stroker single was able to rumble along at low revs without any problems. Went a bit more urgent at 5000 revs but didn't really pile on the power until past seven grand when the tacho swung vividly around to 11000 revs!

The engine was fitted with electronic ignition and the famous power valve (YPVS) system. Along with clever porting, made the motor both pleasant at low revs and quite fierce at the higher end of the range. I don't weigh all that much and the TZR hit the scales at less than 250lbs. This power to weight ratio gave the bike a harder edge than my last bike, a GSX250 Suzuki four stroke twin. Both died a death, as if slamming into a brick wall, at 90mph. More than fast enough for me. Over the weekend, the fuel worked out at 68mpg (compared to 45mpg from the rather worn Suzuki), which was just about acceptable.

The TZR looks quite racy but has a sensible riding position and half decent saddle. Fine, if like me you're on the small side, but its compact nature probably wouldn't suit those with bigger frames. Taking the wifey on the back revealed that excessive mass had an immediate effect on performance and ruined the marginal suspension. But she wasn't keen on pillion work and was looking for an excuse to avoid the motorcycle experience.

The clock read 14,200 miles. The price was £775. There wasn't anything else remotely interesting in that price range, so I ignored my reservations and did the deed. Wearing an open-faced helmet, goggles and an old Barbour jacket, I received a few odd glances as they were in strong contrast to the flash Yamaha. I always had a laugh at the poseurs who wandered around Southampton town centre in full leathers, all oddly baggy in the wrong places once the riders were standing upright.

All went well until the first time it rained. I found the narrow, 17 inch front tyre liked to wander a bit (in the dry). Nothing a tight grip on the low, narrow bars wouldn't keep under control. The switches, by the way, were a touch too small for my fingers encased in proper leather gloves - none of this Gortex rubbish, just thick hide. But when the rain splattered down on the tarmac I found that the front tyre was all too ready to skate over the road. In my humble opinion, a good case can be made for slow reacting 19 inch front wheels on bikes that are light in mass and low in power. Tyres also last longer (9000-10,000 miles in the TZR's case).

The TZR could certainly do with a modified front end or maybe some better rubber than the cheapo Japlops. I had to ride really gently in the wet, try to avoid using the front disc and generally live more in fear than happiness. Time and experience did help a little, after six months it no longer seemed such a great problem as during those first few weeks. Perhaps I'm just a BOF! You wouldn't have guessed that, though, from the fast progress I made through the traffic.

Even more fun was had on country roads where the bike could be ridden flat out. If the front end was a tad imprecise, the lack of mass meant it could be chucked from side to side with hardly any muscle input. On the power, the exhaust wailed, whilst the immensely strong Deltabox frame kept the bike from getting seriously out of hand. The only limit on the extent to which it could be hurled over was the tyres' grip - I only used another replacement set of the same brand because they were available very cheaply.

On the motorway I had to ride the little stroker flat out to avoid looking like an accident waiting to happen. Full of visions of being mowed down by impatient car drivers or becoming the cause of a pile-up. Even ridden like that it bettered 50mpg against a normal average of close to 70mpg - the derestricted TZR's are more economical than their restricted cousins! With a 12 litre tank I could get over 175 miles before having to search for a petrol station. By then the seat was becoming more than a little uncomfortable, though I have done over 400 miles in a day without setting the piles off! Overall, it was pretty easy to become one with the machine and adapt to the way it loved to sing along at ten thousand revs. In fact, large and sensible four strokes of modest power became rather boring to ride.

In 18 months the Yamaha managed to clock up 27000 miles before it started to smoke and rattle. Shot piston rings and bore, but replacements were readily available and easy to fit. I cleaned up the powervalve and fitted a new but heavily discounted exhaust as the old one's matt black finish turned crappy. The engine had a new lease of life and I was a happy man again.

There you go, then. It might not look it, but the TZR's a rather sensible motorcycle for those on a strict budget but who are not yet ready to be consigned to the C90 hordes. I'm tempted to fit a front end off an old British twin to sort out its handling, apart from that it's a bit of alright. Fills my day with lots of fun and makes sure I don't become old before my time.

Alfred Dunning

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I could not believe my luck - my cousin had got his girlfriend in the club and was being forced into a hasty marriage, the only way he could raise the necessary dosh for the mortgage deposit was so sell his beloved, 1988 Yamaha TZR125; prime meat with only 5000 miles of abuse on its clocks. It was even the derestricted, 21hp model. I had the cash and a deal was struck within minutes.

I am an old hand at this motorcycling lark, even if I say so myself, so you can imagine my surprise when I discovered I had bought myself a real fun machine. 21 horses is not all that much but when the bike only weighs 231 pounds dry and sports a Deltabox frame, the motorcycle is able to make the maximum use of what power is available.

I soon found that the Yamaha is the supreme town machine, once my ancient body had adapted to the sporty riding position there was no holding me back. Flicking up and down the delightfully fluid six speed gearbox, keeping the revs in the critical 7000 to 10,000rpm band and riding on the brakes (a single disc of ferocious power and good rear drum) I was soon doing all kinds of mad things in town at speeds more befitting a juvenile delinquent.

If its minimal mass aided flickability, acceleration and braking, it did make for a tiring ride over bumpy and neglected roads. A firm grip was needed on the bars and a certain disdain for the way it was thrown about. Suspension was able to cope with minor irregularities and even high speed bumps in out of town roads, but the kind of pot-holed neglect effected by our local town council went straight into arms and backside in a most disconcerting manner.

Fortunately, the Yamaha remained supremely controllable and I always managed to sneak the ever so narrow single cylinder stroker through the narrowest of gaps that even a C90 commuter would have second thoughts about. There was a kind of exultation in burning off a row of cars, careering past them in the right gear at about twice the advisable speed, assured that if things went seriously wrong and some bored out of his head dork decided to do a sudden U- turn, the Yam could be braked and flicked simultaneously out of harm's way.

Not that the TZR would let you ride in any other way. Sustained slow speed work the machine did not like, oiling its spark plug and running as if it held a grudge against the world. On one occasional, in the wet, when slowed by two lorries blocking most of the road, the plug oiled up just as I was trying to overtake. Death seemed imminent as the vehicles converged rapidly on the space I wanted to shoot through, until suddenly the plug cleared, the front end reared and the machine shot forward like some mad Pitbull about to devour a child. The handling on one wheel was decidedly skittish and only the willingness of a car driver to mount the pavement stopped metal hitting metal. Things become much worse if you forget to replace the spark plug every 5000 miles!

With a weird combination of 16" rear wheel and 18" front, shod with Roadrunner and Jap crap respectively, wet weather riding was always interesting. The tendency of the front wheel to slide away from under you and the rear to step out an inch or two made damn sure the throttle was treated with care and some degree of planning ahead was necessary. 230lbs may well be too little for reassured wet weather riding.

The Roadrunner lasted for an inordinate length of time - over 20,000 miles, although the front only lasted for 15k, perhaps down to the frantic way I employed the front disc. Eventual fitment of a set of Michelins firmed up the handling and gave massive reassurance in the wet.

The bike was generally stable on the open road and just about the quickest thing I've come across to get through a series of hairpin bends. It was so much fun that on many occasions I turned around and did my favourite bits of road again and again. Top speed was normally 90mph but the elusive ton on the clock was achieved a few times - quite literally down a steep hill, with a strong wind behind. Quite fierce vibes buzzed up from the motor as it was thrashed into the red through the gears.

This showed up a surprising quirk in the TZR design, it seemed to become more economical the faster you went - imagine your defence in court, that you were trying to save the environment by running your engine at its most efficient speed! In town it rarely did better than 65mpg, but on the open highways it was no problem to achieve 70mpg. This is better than the 12hp restricted model which a friend's son owned and does 50-55mpg!

If the machine's reasonable on fuel it's main running costs come from chain and sprockets which last little more than 8000 miles and front disc pads which are even worse at 6k, although I work the single disc so hard that it glows red hot in the dark! Pattern chain and sprocket sets are only twenty notes, so their early demise is not as bad as it could be. Also the rear shoes are still original and unlike the front, which required a 10,000 mile strip to avoid seizure, needed no attention.

With 29000 miles on the clock I was rather alarmed to find the front forks juddering badly under braking. This was traced to a cracked disc! I spent many a sleepless night fitfully imagining what would have happened if it had failed at a critical moment.....the replacement from a nearly new bike in a breaker only cost £15 and is given a daily look over.

Another expense is the battery which rarely lasts for much more than 15k, evidence of its poor state being constantly blowing front bulbs. With 41k on the clock the rest of electrics have behaved themselves, no ignition or charging problems. Even the switches are original and still work as nicely as ever.

Maintenance is a doddle. There's hardly anything to do. Checking the oil pump setting occasionally and changing the gearbox oil every 10,000 miles, the rest takes care of itself. Ridden hard the bike uses about a litre every 500 miles, less fervent craziness improves that to about 750 miles to a litre. That compares well with changing three or four litres every 1000 miles, and is a lot less hassle than on a four stroke.

Using good quality oil in the engine means that the normal stroker blue haze is pretty minimal, only in evidence on starting up or under very hard acceleration. The watercooled engine has been extremely reliable since I've owned the machine, it seems to thrive on being thrashed, preferring it to pottering about in commuter mode. I can see absolutely no need to let such a machine near a dealer for servicing.

It's still on the original exhaust, thanks to the oil coating from the two stroke process, although externally the black finish has turned rusty. There are quite a few aftermarket systems available that claim to boost power but I have to admit I'm not that enamoured by the stock wail and don't want my head subjected to the noise of Allspeeds and the like. Tank paint is still good but there are specks of rust breaking out all over the chassis, especially on the screws.

The Monocross rear end is still stock and shows no sign of wear despite the fact that I have not stripped down the shafts. The shock became a good imitator of a pogo stick after 30,000 miles but as the bike itself has always done a good pogo hop over bumps I haven't bothered to replace it. The front fork seals went at 15k when I was imprudent enough to slop in some thicker oil and went again at 25 and 33k even when I used the proper grade. The pitted forks doubtless don't aid longevity.

Even at its current mileage, the engine comes to life first kick, I can detect no diminishment in acceleration, top speed nor economy and it gives every impression of wanting to run and run. That's in contrast to the machine of my friend's son which was dead after only 15000 miles (despite being in 12hp form) - the motor seized solid and almost spat the youth off the seat. The dealer diagnosed a seized motor due to a lack of oil.....he had forgotten to fill up the tank! I bought the machine off him for a few hundred quid, so it seems I'm set up with enough spares for the next few years.

Gerald Parker