Tuesday 17 January 2012

Kawasaki AR125

The hundred quid hack was all I could afford. It didn't even run but was whole. That was what the 125 world had come to. Anything interesting was either expensive or a wreck. Sometimes both. I pushed the bike the six miles home. None of the bikers who sped past bothered to stop.

The AR isn't the most flash 125. But it's been around for yonks with lots of spares in breakers. That's where I headed for some engine parts. I'd stripped the top end off the AR to find a ruined bore and piston. The small and big end bearings were okay, so I had a lucky escape. Forty notes secured a barrel and piston.

The watercooled engine was easy to work on. I'd had lots of practice tuning old mopeds. The only thing to watch was for the studs stripping in their threads. Either a torque wrench or a good touch were needed. Old gaskets smeared with Hermatite were used in the reassembly.

The AR had been standing for so long that the tyres had rotted and corrosion had obscured much of the chassis. The breaker gave me some reasonable Jap tyres, skinny enough to suit a push-bike. I spent a whole weekend cleaning and patching up the chassis.

It was all together for the beginning of the week. A reluctance to start was down to a duff spark plug. Riding off to work I was a bit worried by a misfire below 4000 revs. It threatened to kill the engine dead. I was given some fish-eyed looks as I stoked the throttle up at junctions.

Coming home it ran better. I guessed there was some crud in the carb from standing so long. The Unitrak back end felt a bit loose. Pot-holes sent the bars into some fearsome twitches. It more or less went where it was pointed. Until the front tyre exploded. I was only doing 25mph. Managed to pull over, both feet down to control the wobble.

It wasn't the tyre that had gone but the cast front wheel. A crack ran through one of the spokes and the rim. I've never heard of any other AR's doing that. It must have been in an accident. Not very inspiring. Some desperate pleading secured a corroded wheel for £35.

Luckily, the bike was still where I'd left it parked the next day. There was no way it could be pushed or pulled along with the wrecked wheel. AR125s only weigh 230lbs but that's too much to single-handedly drag across town. Curious juveniles gathered as I did the transplant. They seemed surprised when I was able to ride the bike away.

The AR was less than five years old but looked worse than most 20 year olds. I still hadn't passed my test, so couldn't derestrict the motor. Its twelve horses was good for 75mph. But only down a hill with a following wind. Usually 65 to 70mph was the most it'd buzz up to.

The gearbox operation was one of those acquired arts. I'd experienced worse on an old Honda moped. But not much. Gears once firmly engaged didn't slip out again. To the extent that the box would sometimes lock into gear. Depending on the ratio this could be amusing or hell. The only way to change gear then was to let the motor cool its heels for ten minutes. The mileometer suggested the engine had done 21000 miles. The gearbox two to three times that.

Apart from these minor irritants the motor was holding together well. The chassis appeared to be rotting away beneath me. Fork seals lasted 500 miles. Calipers gummed up every time it rained. Which was pretty much every day. The rear brake locked solid sending the bike into a wild skid. When I hit it with the hammer the alloy housing cracked. My mates reckoned it was I who was cracked from riding such an old dog.

This litany of minor disasters carried on as the months and mileage piled up. The silencer cracked around its circumference and fell off. I wasn't sure if it was the vibes or rust. Or a combination of the two. It didn't matter what I thought. The engine thought it was a restricted fifty with a violent, chainsaw wail. I popped into the breakers before they locked me away.

Still, the engine ran. It belched a bit of smoke in town. Would oil its plug after fifteen minutes of slow work. If it wasn't cleaned out with a fast blast a new plug was needed. Cleaning the old one was a waste of time. I had to carry a couple of spares just in case. With everything sorted there was a broad range of power. Better than most other 125s. Fuel was good, at 60 to 70mpg.

When the wobbles finally became too terrifying I took the back end down. Parts from breakers saved a lot of hassle in reconstructing the UniTrak and swinging arm bearings. The only difficult job was removing the swinging arm spindle. The blows from the hammer jarred my body. God knows what they did to the little Kawasaki.

That just left the front end in a rather sad state. Pitted forks, a wrecked caliper and worn out tyre. It was cheaper to exchange it for a newish one at the breakers. Total cost of the cycle parts was £65. I enjoyed putting the shiny bits back together.

I wasn't disappointed with the stability. Just the slightest fluttering flat out. Town work was a breeze. It could be a real giant killer. The thing to catch me out was the mirrors. They hung out a long way, would hit the sides of cars when I wasn't paying attention. I just kept going, no point giving a cager a chance to beat me up.

About 8000 miles after the rebuild the silencer started pissing out steam! The cylinder gasket had finally failed. I quite enjoyed leaving behind huge clouds. New gaskets sorted the problem. I noticed that the piston was a bit scruffed but the bore looked fine.

In one of those silly manoeuvres that you curse afterwards I was involved in an accident. I decided to do a sudden ninety degree turn. Some cyclist had assumed I was turning left rather than right. He went over his bars into my lap. AR and I toppled over. I cracked my helmet open, was left a bit dazed. The next thing I knew I was frog-marched into an ambulance and spent hours in hospital. I kept insisting on leaving but they ignored me.

The police had carted the AR away, were reluctant to return it to me. The cyclist was threatening to sue me. I had visions of never ever again being able to insure a motorcycle. The AR had a few dents that were sorted with filler and paint.

After that incident it never seemed to run so well. It may have been all in my mind. It veered slightly to the left. The mill kept grinding out vibration every time I tried to crack 70mph. There was not much that could be serviced. All I did was change the transmission oil and check the fluids.

I guessed that the next engine rebuild would involve replacing the crankshaft. The gearbox was also becoming even worse. That all added up to a major expense. It'd be cheaper to fit an engine out of a crashed bike.

I kept the AR until I passed my test. Not an ideal contraption for this purpose. It looked a little loud in the bright yellow I'd applied. If the gearbox seized during the test I'd be deep in execrement. It didn't. I polished the whole bike until it shone and put it in MCN for £350. I accepted £300 and bought myself a crashed Suzuki GS450.

Kev

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I was a bit dubious about a seven year old Kawasaki AR125. Not helped any by the open carb, loud spannie and chortling youthful owner who couldn't live without blipping the throttle. He reckoned the watercooled stroker single had a complete rebuild, almost to race spec, 4000 miles previously. He was only selling it to take his sick mother on her last holiday!

The test ride revealed that there was no power below 6000rpm, thereafter it came in like a crossbow bolt going off. This highly reprehensible, if not illegal, little missile almost endeared itself to me when I became lost in the gearbox, ending up in second instead of fourth with a wide open throttle. The owner's grin wasn't diminished by the spectacle of me scraping along on the numberplate in maximum wheelie mode. He confided that she was a smashing little number and I couldn't find it in my heart to disagree.

For the next couple of weeks I displayed a commendable caution on the throttle until I'd grown fully confident in both my own and the bike's abilities. Weighing in at only 300lbs meant that the AR was dead easy to control but was also thrown about by road shocks, side winds and the airstream of large vehicles. The desired path was often ruined by such obstacles, making the AR both frustrating and even a little dangerous.

The crazed nature of the power delivery didn't help one bit, but then it did sport something like 30 horses instead of the obligatory 12 judging by the way the howling engine would shove the Kawasaki up to the ton! Unfortunately, the suspension had not received much attention, was worn to the point where anything above 70mph threatened to turn cataclysmic.

The first time I hit a big bump at speed I thought I was going to die. The bars seemed to lurch right out of my hands, shake wildly for a hundred yards, leaving the whole bike in the kind of lurches I'd only experienced previously in a fairground. Below 70mph the suspension was still capable of holding the plot in line.

Rather than do anything expensive like buy new suspension components I hit the breakers for stock carb, filter and exhaust, only £25 for the lot. With these fitted I was immediately impressed with the new found civility of the motor, with plenty of torque between 3000 and 8000rpm. Top speed was radically reduced to about 80mph, which was still better than stock - the internal porting mods were not totally subsumed by the restrictive induction and exhaust mods.

Another cause for joy was the 75mpg economy instead of a pathetic 40mpg previously. Starting had also become a first rather than sixth kick affair, even if the spark plug would still oil under extended town use. Sometimes it'd clear up under a bit of throttle abuse, other times I had to change it for the spare that I always carried, not being a complete novice in the ways of strokers.

The engine went through oil at the approximate rate of a pint every 100 miles, which seemed excessive, as shown by the amount of exhaust pollutants. Idling for more than a minute left the immediate area covered in quite a dense fog. If the wind was blowing the wrong way I had to inhale a very painful amount of burnt off oil, that left me coughing like an eighty year old asthmatic.

As the engine had soon started rattling like the piston rings were breaking up I had no intention of adjusting the oil pump to a milder setting. I was relieved to find that other AR's rattled just as noisily as mine despite the watercooling and there was no immediate drop off in performance.

A good engine can be most easily sussed by the presence of a slick gearbox. Despite having its own oil supply, lubricant needed to be changed every 1000 miles if a passing resemblance to a grinding machine was to be avoided. Even with new oil my box was far from easy to use, suddenly finding false neutrals where it'd been previously polished. After a while I became used to it and smooth engagement of gears became the norm rather than the exception.

It was important to maintain the sprockets and chain in good shape to keep the gearbox working. Effectively, this meant replacing them every 7500 miles! Yes, utterly pathetic for such a light, low powered motorcycle but I did use the cheapest set I could buy. Huge quantities of oil were thrown off the chain, by the way, leaving the back end and any pillions not sporting waders deep in grime. I did have a passing thought of using some kind of condensing mechanism on the end of the exhaust to divert the oil that was spewing out on to the chain!

Apart from regular chain adjustments, spark plug replacements and putting oil in the tank, the rest of the bike was relatively free of maintenance chores. The first on the road failure was the result of this wanton neglect - the back tyre had picked up a nail and ended up shredding the inner-tube. The wobble when the final deflation occurred was intense enough to cause us to run off the road, completely out of control. I narrowly missed being mashed by a couple of cars and almost felt relieved when we hit some grass, sliding along until a fence stopped our progress.

Damage was minimal, the AR being narrow with everything well tucked in. I sprained an ankle which sent shudders through my body whenever I placed any weight on it. A van driver actually pulled over, insisted on running bike and I to my house some five miles away. He was an ex-biker who bitterly regretted his marriage and mortgage, regaled me with tales of misdeeds on an RD400. He also agreed to buy the AR off me, until he figured out what would be his wife's reaction. My ankle took a lot longer to recover than the AR.

The second on the road failure occurred after about 12000 miles of abuse. The piston seized up when we were rolling along at about 60mph. The locked up back wheel sent my heart rate crazy until I hit the clutch. The reason for the failure was that I never bothered to check the coolant level which had dropped so far that there was only steam left in the radiator. I knocked on someone's door demanding a bucket of water as a temporary solution. I received some very funny looks from the old girl but she eventually acquiesced and the engine cooled off after a while to loosen up the piston.

The journey home was accompanied by terminal rattles and enough smoke to have fire engines rushing to the scene. When I took the cylinder off I was relieved to find that the bore was okay, the rings had just collapsed into the piston - only thing was that the small and big ends were shot! Oh well, the AR was about due for an exchange crankshaft.

The bike was only off the road for two weeks, allowing me to also fit some new bearings in the rear suspension and put in a nearly new shock. The rebuilt motor, as is often the case, performed less well than of old even with 250 miles of careful bedding in. Top speed was only 75mph (under favourable conditions, usually it was only 70mph) and fuel consumption was around the 60mpg mark. The stability had improved noticeably, allowing me to hammer along flat out whenever possible, so journey times were often shorter.

The third failure was down to the generator burning out, blowing every electrical black box on its way to oblivion. This ain't a common demise, used bits readily available from breakers but I found that a lot of the wiring had turned brittle, a rewire becoming necessary. I never did get the indicators to work properly again, but hand signals and a loud horn sufficed. The lights and switches were pretty much what you'd expect on a bike of this size, adequate rather than in any way brilliant.

A further 9000 miles were done after the rebuild, with just the electrical hassles by way of trouble. I'd owned the bike for just over two years, which was more than enough for me. I yearned for something newer, bigger, faster and flasher. As it was back in 12hp spec by default rather than planning I had no trouble selling the AR to an eager learner for what I'd originally paid. I'd had quite a few expenses along the way so it wasn't a free ride but I felt I'd had good value and plenty of good times out of the experience. They ain't bad bikes overall.

Dick Williams