The Yam RD125LC is still one of the most popular lightweight bikes, so my further experiences with the LC previously reviewed in the UMG may be of interest. As the LC's speedo approached 30,000 miles I felt some foreboding of imminent expensive mechanical or electrical disaster.
The bike has now reached 35000 miles and I will relate its recent history. My LC is a 21hp model, which with an Allspeed and bigger main jet can reach 90mph. Petrol consumption is only around 60mpg and as the Allspeed rusts through after only three years I am tempted to revert back to stock and enjoy improved consumption of 70mpg. I have owned the bike for over seven years from new and have full service records so can give reasonably accurate wear rates for tyres, etc.
I use the bike's performance whenever road conditions allow but never over rev it. Rear tyre life has averaged 4500 miles and front 11,500 miles. Chains last about 9000 miles and sprockets 11,500. Heavy wear reflects performance which is better than some 250s. Chain and sprocket sets are relatively inexpensive. Front brake pads have been replaced once in 35000 miles but the rear brake shoes three times.
Electrical replacements in the machine's life to date have been the indicator switch at £17, flasher black box £12, temperature gauge sensor £17 and battery which lasted seven years. The bike passed 30,000 miles and continued to perform well, however at 33000 miles slight traces of clutch slip were noticed if the bike was accelerated hard. After another 1000 miles the plates and springs were replaced for the first time (£18). At 34500 miles increased oil consumption was noticed together with some piston noise, indicating a worn bore. Up to this time the cylinder head had never been removed...
I am very attached to the LC after owning it for so many years. It seems to have more character than most Jap bikes and has certainly been the most reliable bike I have owned in 30 years of motorcycling. I decided to restore the bike to as new condition.
The restoration turned out fairly expensive, mainly due to cosmetic damage caused by a series of prangs in '87, which in retrospect were caused by my trying to go faster than my reactions could cope with. Anyway, the road is hard, so this series of prangs without personal damage had the desired effect and I slowed down and stayed on. The headlamp fairing, panels and tail were repaired and repainted by Dream Machine, who did a good job.
The engine was overhauled by my local Yamaha dealer who sold me the bike originally and has maintained an interest in it. The bottom end was found to be perfect, the bore was worn and bored to accept the first oversize piston. A new piston with rings cost £27, a new gudgeon pin £4, the small end £6 (it looked perfect but was replaced as a precaution). New gaskets were fitted throughout. I think the engine has worn really well, considering its small capacity and high performance.
I next turned my attention to the cycle parts. The handling had deteriorated as I found when challenged by a DT125LC rider on a twisty road. I saw him off but nearly frightened myself to death in the process. I realised the rear shock was worn and replaced it with a new Yam shock for £60. Roadholding is now good, but not as good as my TZR125.
The front disc's piston had partially seized for the second time, it was rectified and Goodridge hose fitted, the brake becoming superb. The rear brake seized due to all the salt on the road in winter. The six speed gearbox is still perfect and superior to that of the TZR!
The LC looks almost as good as new. The motor, which I'm now running in carefully, is as smooth and quiet as ever. I look forward to many more happy years with this machine.
Vince G Dusang
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There are some bikes that get into the mind so deeply that they are hard to shake off. In 1985 I learnt to ride on a brand new Yamaha RD125LC. A fantastic year's riding followed with only the consumables replaced. Test passed, there followed a couple of years on RD350s which were even more fun but a bit finicky and unreliable. Then came a job with a car and no bike until 1992 when the job disappeared and I suddenly needed some kicks.
Enter a 1986 RD125LC with 30,000 miles on the clock. This one was derestricted, the watercooled single cylinder motor putting out about 20 horses. It wailed and screamed, shot off up the road, which resulted in a big smile which I couldn't hide from the vendor. My face was all lit up judging by the way he refused to budge on his price. Well, it was a one owner in good cosmetic condition and I'd had a big pay off from my employer.
These bikes are neat bits of engineering, Yamaha at their best. With watercooling and a reed valve, the motor wasn't exactly simple but very robust for a stroker and pretty easy to control even in derestricted form. By modern standards the styling might've looked a little dated but I think it has a quiet charm all of its own that in ten years time will still be attractive.
I seem to recall that my bike didn't weave at 70mph like the one I'd just bought. I put it down to the passage of time, rose-tinted memories and all that. At least until the weekend when I poked around the chassis. There was some movement in the rear wheel. I thought the bearings were shot but the wheel spacer had been replaced with ill-chosen washers. A visit to the breaker and the large sum of 50 pence procured a proper spacer.
The RD might have an old fashioned tubular frame but it's a good one with plenty of rigidity to withstand its 220lbs and 20 horses. With the back wheel sorted its stability more than matched my memories even with as much as 85mph on the clock. Because it weighed so little bumpy roads would give me a pounding and let the chassis bounce around on its springs. It always felt controllable and never seemed to come close to a speed wobble.
There was a sharp outpouring of power from 6000 revs onwards. The kick seemed out of all proportion to the machine's cubic capacity and power output. Part of it must've been down to the directness of the two stroke power cycle, part down to the low mass and the final part down to the way Yamaha had matched the reed valve with the exhaust system. The 12hp version tended to die a death at 7000 revs, which whilst an ideal restraint on learners would've been boring for the more mature motorcyclist.
Derestricting the motor removed some of the friendliness at low revs, although the engine still ran it sort of burbled rather than crackled. Even in 12hp form it had quite an appetite for spark plugs that was even worse in my bike. Every 800 miles I had to put a new one in, to avoid a motor that spluttered and coughed when in town. When the thing suddenly caught with the throttle wrapped open, the front wheel would rear up as the power screamed in, and I'd have to throw myself forward with a back wrenching viciousness.
It was a lot easier to change the plug before it gave any trouble. Modern oils meant that there was little of the coking up of old, with only the mildest cloud of burnt oil out of the exhaust. With electronic ignition there was nothing to do to the engine other than check the oil tank level and change the gearbox oil (every 2500 miles).
Deciding that I'd keep the bike for a while it seemed like a good idea to rip the rear swinging arm and mono-track suspension out to grease the spindles. A wet and wintry autumn was threatened by the weather forecasters. Everything came apart easily, the as new bearings were well greased. Because of the lack of protection from the rear mudguard, the area is attacked by all kinds of gunge. The spindles can be quick wear but they last okay if given a six monthly strip down and grease. It makes all the difference.
The past owner had obviously gone to some lengths to make the RD long lasting. The chain was an O-ring job that hardly ever needed any attention (plain chains wear out in about 5000 miles). The electrics were mounted on extra rubber and smeared with Vaseline (flat out, the engine gets a little tingly which can affect the stock electrics). The forks had gaiters and the calipers had been rebuilt. The alloy on the wheels and forks never corroded because they had been coated with some clear varnish.
Before the winter set in for good I thought it'd be neat to do a week's touring to really test the limits of the RD. They do lose a lot of their go with a pillion on the back. The mass also crushes the rear shock and makes the bike bounce all over the place. I limited myself to a small tent, a few clothes and a sleeping bag. I want to enjoy myself not get into a fighting match with a grossly overloaded bike.
All went well as I headed for the Scottish lowlands, some 150 miles from my home. I was able to hold 80mph on the motorway, the tiny handlebar fairing doing a surprising job of keeping off the wind and the motor wailing nicely. Then the rain started falling and didn't stop for the next four days. I ended up in a Glasgow hotel dodging around the town in between rain bursts, having dumped the RD in the hotel's garage. Glasgow is a weird place with areas of massive depredation, which had me legging it pronto and lots of old, interesting buildings in the centre. I never fully understood the Scottish sense of humour and was happy to head for home.
It was still pissing down, I was soaked through within minutes but persisted, riding the Yamaha on the edge of its Metzeler tyres. On the motorway there was no choice but to hustle along at 80mph, the cars would've thrown me off the road if I went any slower. The rain became really frenzied, visibility poor and my brain responding to my frozen extremities with pain messages on a par with an exposed nerve from a rotted tooth.
About a 100 miles from home there was a horrible, grinding noise running through the engine, screams of tearing metal not so much heard as felt through the chassis. I hit the clutch just after the back wheel seized solid. The momentary skid was vicious enough to have the back wheel all over the place. If I'd been a moment slower I would have been thrown down the road, torn asunder from an 80mph assault on the concrete surface.
As it was, we had hobbled to the hard shoulder where I sat on the bike, water dribbling out of my clothes, soaked so far through that my underwear squelched whenever I moved. Like a beacon in the middle of a sea of swirling madness the rescue service's telephone stood ten yards away. I dragged my body, carrying about a ton of excess water, to it and got the AA to come to my rescue. Before they turned up I'd managed to change into some dry clothes by draping the tent over the telephone, so narrowly missed out on the joys of dying from pneumonia.
It took me a good month to become interested in the RD again. The engine had obviously seized (with 39000 miles on the clock) and was going to cost lots of dosh to repair. What had happened was that a big bit of the reed valve had found its way into the engine, leaving the bore scarred and the piston broken. The crankshaft felt like it was due for some new bearings so I started hunting down a secondhand mill.
Several breakers were visited before a suitable motor was found, out of a crashed bike that still sported its L-plates, so I was pretty sure that it was in 12hp form and not unduly thrashed. Putting this engine in my frame was painless but I bought a new reed valve just to be on the safe side. I soon had the motor set up in full power tune and a few spins on ice covered winter roads revealed that it was, indeed, a good ‘un.
The year was started off in good form by showing a mate on an CB250RS who was boss. The Yam was more than a match for most four stroke 250s, being almost half the mass and not having that much less power. It was a real ego boost to burn off these bigger bikes and at around 60mpg fuel was just as good, if not better.
The sight of a well put together RD350LC stopped me dead in my tracks. More nostalgia and dubious memories. The owner turned up and only wanted £500 for a quick sale. It was in such nice condition that I could not resist despite the bad recollections about its lack of mechanical reliability.
I kept the 125 for a while, but it seemed to lack the verve of the bigger bike in direct comparison. The only thing I really missed was the economy, as the RD did no better than 35mpg and tore through the consumables at a rate that must've made tyre, pad and chain manufacturers extremely rich. But the kicks seemed to make that worthwhile. The 125 went to a good home, some forty year old who wanted to get into biking. I gave him a blast on the back of the 350 to show him what he had to look forward to.
J.K.
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I will start well into my biking career with an RD125LC. A Mk.1 full power model of 1983, costing a mere 175 quid- cheap at the time as it appeared to be in very good condition. Already fitted with a K&N filter, jetted carb and a very, very loud Micron pipe, ear-plugs were essential! Two weeks was all it took for the local plod to give me a choice - keep the illegal pipes and take the consequences (probably life imprisonment) or fit something quieter. I chose a legal Micron.
I still recall my fist blast down the road After a selection of small four strokes, the same handful of revs and dropped clutch saw me off up the road like a smart suited git to a Volvo auction - scared myself shitless. From then on I was hooked on strokers. There's nothing quite like the frenzied howling of a good stroker.
Over the next two years I amazed myself. I generally keep a bike about six months before boredom or self-destruction sets in. Somehow the RD was different, never boring and a massive grin factor on each and every ride. However, it was not long before problems began to emerge. The dreaded sound of piston slap began to filter through the induction and exhaust roar. Not the kind of thing to ignore, not unless you wanted the joys of a stroker motor seizing up at high speeds.
Without undue haste, I quickly beat it into submission with a rebore, piston and rings. The rebore was done by a mate down the road for a tenner and the piston and rings purchased from the local Yamaha dealer. About a week after the rebuild, screaming across town, the bike started to slow down. No matter how much I twisted the throttle no more power was available. Down through the box, full throttle, again to no avail. Heat rose off the engine as if it was going nuclear.
I stopped in a lay-by to let the engine cool down. Resulting in 25mph in top gear at full throttle. I was overtaken by an old codger on a step-thru! At least the bike made it the three miles home, no need to test my endurance by pushing it. On stripping down the piston looked like I'd taken a file to it; scored was an understatement. Matched by the bore - another rebore, piston and rings, and a weekend's rebuild.
Back on the road, the RD was great fun to ride after I'd run it in properly. A bit peaky, due to the mods, and after one Saturday morning's porting job (copied from an article in Performance Bike) the revs reached dizzy heights. Nothing below 8000rpm, but from there onwards to 13000rpm it was just a blur. Countryside and tarmac just merged to add to the confusion. Once I became used to it, great fun!
The single front disc with braided hose gave a good feel. I can't exactly say it was progressive but you always knew what was going on. Until coming out of my garage one afternoon, at a fair turn of speed, applied the front brake, started to slow down then all of a sudden the lever came all the way back to the bars. Stamped on the rear pedal and stopped just short of the road.
As soon as I regained my nerve I took a look. A small hole had appeared in the braided hose, looked as though the hose had chaffed the fork guide. The fun began when I tried to fit a new hose. Easy to remove, the new one went on a treat, but when it came to bleeding the caliper, forget it. The caliper was seized solid, no way I could shift it. Off to the local breaker for a replacement for all of a tenner.
The new brake lasted for half a dozen pumps on the lever. Drained the system again, the only area left to check was the master cylinder- its rubber skirt was split. Yet another trip to the breaker but at least I was soon back in business.
MOT time again. Yes, I do believe in being legal, which includes tax and insurance. It's the MOT I hate the most- your pride and joy's pulled apart in front of you, then the smug git turns around with that grin. You've failed! This time it's the rear wheel bearings.
Taking the back wheel out was fun. The use of bricks and a piece of wood to keep the bike upright; no centrestand. On finally pulling the wheel out the sprocket's side bearing just fell out. I must admit I never even noticed it was that bad, but it wasn't the bearing causing the slack- the hub itself had worn away! Chemical Metal was smeared around the new bearing before it was fitted! Passed the MOT the next day.
The chassis was next. A nice spray job in red and yellow, which faded into each other. To give it a real sporting look I fitted a single saddlle and old seat hump, to which the light and numberplate were bolted. Overall, quite an impressive pocket rocket.
Fun was had fitting a new set of tyres, although they lasted for two years. I was quoted a ridiculous sum for fitting the new rubber to loose wheels. I found out why when the tyre lever slipped, came flipping back in an attempt to take out my kneecap. Instead it whacked my shin! Aaaargh! Brought tears to my eyes.
Other bruises came from the time I tried to split an endless chain. The hammer and punch routine left my fingers well bloodied. Even when the rivets moved a little, I finally had to grapple with the oily mess to get it apart. It's worth fitting a HD chain as adjustment's quite frequent due to the fiery power.
Another year, another MOT. A quick ring of the local dealer for an appointment only to find the only time available I couldn't make it. A friend was given the honour of riding the bike there, only to come back an hour later with a fail. A free retest if I could fix it fast, the rear bearing gone again. No time for Chemical Metal. I hammered the boss so that the material spread inwards, producing a tight fit for the bearings. Nice and tight, one MOT pass. Soon after that I passed the driving test, the bike quickly sold in favour of an RD250LC- what else could I buy after so many happy years on the smaller Yamaha?
Lippy
I still recall my fist blast down the road After a selection of small four strokes, the same handful of revs and dropped clutch saw me off up the road like a smart suited git to a Volvo auction - scared myself shitless. From then on I was hooked on strokers. There's nothing quite like the frenzied howling of a good stroker.
Over the next two years I amazed myself. I generally keep a bike about six months before boredom or self-destruction sets in. Somehow the RD was different, never boring and a massive grin factor on each and every ride. However, it was not long before problems began to emerge. The dreaded sound of piston slap began to filter through the induction and exhaust roar. Not the kind of thing to ignore, not unless you wanted the joys of a stroker motor seizing up at high speeds.
Without undue haste, I quickly beat it into submission with a rebore, piston and rings. The rebore was done by a mate down the road for a tenner and the piston and rings purchased from the local Yamaha dealer. About a week after the rebuild, screaming across town, the bike started to slow down. No matter how much I twisted the throttle no more power was available. Down through the box, full throttle, again to no avail. Heat rose off the engine as if it was going nuclear.
I stopped in a lay-by to let the engine cool down. Resulting in 25mph in top gear at full throttle. I was overtaken by an old codger on a step-thru! At least the bike made it the three miles home, no need to test my endurance by pushing it. On stripping down the piston looked like I'd taken a file to it; scored was an understatement. Matched by the bore - another rebore, piston and rings, and a weekend's rebuild.
Back on the road, the RD was great fun to ride after I'd run it in properly. A bit peaky, due to the mods, and after one Saturday morning's porting job (copied from an article in Performance Bike) the revs reached dizzy heights. Nothing below 8000rpm, but from there onwards to 13000rpm it was just a blur. Countryside and tarmac just merged to add to the confusion. Once I became used to it, great fun!
The single front disc with braided hose gave a good feel. I can't exactly say it was progressive but you always knew what was going on. Until coming out of my garage one afternoon, at a fair turn of speed, applied the front brake, started to slow down then all of a sudden the lever came all the way back to the bars. Stamped on the rear pedal and stopped just short of the road.
As soon as I regained my nerve I took a look. A small hole had appeared in the braided hose, looked as though the hose had chaffed the fork guide. The fun began when I tried to fit a new hose. Easy to remove, the new one went on a treat, but when it came to bleeding the caliper, forget it. The caliper was seized solid, no way I could shift it. Off to the local breaker for a replacement for all of a tenner.
The new brake lasted for half a dozen pumps on the lever. Drained the system again, the only area left to check was the master cylinder- its rubber skirt was split. Yet another trip to the breaker but at least I was soon back in business.
MOT time again. Yes, I do believe in being legal, which includes tax and insurance. It's the MOT I hate the most- your pride and joy's pulled apart in front of you, then the smug git turns around with that grin. You've failed! This time it's the rear wheel bearings.
Taking the back wheel out was fun. The use of bricks and a piece of wood to keep the bike upright; no centrestand. On finally pulling the wheel out the sprocket's side bearing just fell out. I must admit I never even noticed it was that bad, but it wasn't the bearing causing the slack- the hub itself had worn away! Chemical Metal was smeared around the new bearing before it was fitted! Passed the MOT the next day.
The chassis was next. A nice spray job in red and yellow, which faded into each other. To give it a real sporting look I fitted a single saddlle and old seat hump, to which the light and numberplate were bolted. Overall, quite an impressive pocket rocket.
Fun was had fitting a new set of tyres, although they lasted for two years. I was quoted a ridiculous sum for fitting the new rubber to loose wheels. I found out why when the tyre lever slipped, came flipping back in an attempt to take out my kneecap. Instead it whacked my shin! Aaaargh! Brought tears to my eyes.
Other bruises came from the time I tried to split an endless chain. The hammer and punch routine left my fingers well bloodied. Even when the rivets moved a little, I finally had to grapple with the oily mess to get it apart. It's worth fitting a HD chain as adjustment's quite frequent due to the fiery power.
Another year, another MOT. A quick ring of the local dealer for an appointment only to find the only time available I couldn't make it. A friend was given the honour of riding the bike there, only to come back an hour later with a fail. A free retest if I could fix it fast, the rear bearing gone again. No time for Chemical Metal. I hammered the boss so that the material spread inwards, producing a tight fit for the bearings. Nice and tight, one MOT pass. Soon after that I passed the driving test, the bike quickly sold in favour of an RD250LC- what else could I buy after so many happy years on the smaller Yamaha?
Lippy