Yamaha RD125LC restoration

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Mark Rouse had been without a bike for 26 years when his mate Chris Tring found him the dream machine from his youth, a Yamaha RD125LC. It started him on the path to resto redemption...

ark Rouse has missed out on bikes. At 16 he’d had a Yamaha RD50MX and did that thing of nailing it about with his mates on their 50s. For one afternoon he got to ride an RD125LC, too, and loved it – vowing that it would be the next bike he’d own. Sadly his parents and grandparents thought otherwise and, at 17, helped with the money to buy a car instead. Four wheels became his new passion and the bike scene passed him by.

Five years later he met a bloke who lived in the flat upstairs from his girlfriend (now wife), Emma. He struck up an immediate friendship with that man, Chris Tring, never suspecting that 22 years later Chris would help him buy that RD125LC.

“Chris has been a great mate since 1992,” says Mark, who also left this photoshoot to Chris given that he couldn’t get the time off work. “While all that time he’s been into bikes I’ve never joined him in that. Then a couple of things happened. First, about two years ago Chris took me on the May Day run down to Hastings on his MV Agusta F4. It was agony on that pillion, but the excitement of all those bikes got me thinking it was time I got one. Then my father-in-law passed away and it prompted Emma and I to get on with life, not wait. I remember sitting on a beach in Tenerife, idly flicking through eBay on my mobile, when I looked up RD125LCs. I showed Emma and she just said, ‘Go for it.’
It was time to revisit that childhood dream.”

Chris, as it turned out, was an ideal mentor. Bikes are in his blood, and he can recall his first resto was an RD250LC back when he was about 22: rebuild, new paint plus performance mods. He’s continued on since then. He’s not a total classic buff though, for while he’s been restoring a Honda MBX125 (seen in PS’s Restoration Advice, February 2016 issue) he’s also been going over an eight-year-old MV Agusta Brutale. ‘Pimp’ would be a very unkind term, but he’s certainly transformed it with striking new tri-colour paintwork, repainted wheels and some sweet detailing. Helping to restore an RD125LC was well within his capabilities.

The bike you see here was found by the pair at a local dealer specialising in imports. Flagged up on eBay, they shot round there and found the RD sitting in a container – with several other bikes leaning up against it.
“As ever, the better the bike you start with the easier the job will be,” says Chris. “This was a good one. Being a Swedish RD meant it was a bona-fide, full-power model. But as well as that it was all there, with 9000 miles on the clock. I said to Mark, ‘If she runs, we’ll take her.’ It did, and with a little haggle I got the dealer to drop from £950 to £800.”

The pair took the RD back to Chris’s workshop. Mark was shocked to find that within two days they had the bike broken down into hundreds of pieces.

“I work in the motor trade and to do the same with a car would just take so much time and space. I was amazed and impressed at how quickly work progressed.”

The first setback they experienced was seized swingarm bearings, quite a common fault given that the phosphor bronze bushes almost never get to see any maintenance. It’s not a happy find, either, given the swingarm bolt also goes through the rear engine mount. Days of soaking the bushes with releasing agent, then a good belting with hammers, eventually got the swingarm freed. Needless to say the bushes and bolt were replaced.

The engine was first up for some fettling. It didn’t need a rebuild, but it needed some sorting. “It ran lumpy when I tested it and I immediately figured it might be the crank seals, as they’d have dried up from years of standing,” explains Chris. “We looked online for a lead on renewing these and found a useful video on YouTube, which showed the technique and special tools needed.

“We bought the parts and tools necessary and did the job. It’s handy that the engine is a single as there are just the two outer seals and no labyrinth seal, so once we’d pulled the stubborn flywheel off it was straightforward to pick the old seals out and tap the new ones into place – no need to split the cases.”

Inspection revealed the top-end to be fine and given that the bottom-end hadn’t made any rumbling sounds and the gearbox had selected all gears easily, save for a precautionary set of new clutch plates it was simply a case of a new sparkplug and fresh oil – plus a detailed clean, of course – to see the motor refreshed.
The carb, too, needed a thorough clean. “There was 20-year-old dirt in the float bowl and the brass jets were green and furry,” says Chris. “The needle seemed to fit nicely and showed no wear but once we’d cleaned it all up it wasn’t running right. Mark bought a carb refurb kit and that got it as good as new.”
The frame went off to Chris’s cousin for shot-blasting and a powdercoat – and a very tidy job it is, too. The swingarm was also shot-blasted and the lads then painted this with a matt aluminum silver paint that saw duty on the footrest hangers as well. Chris had recently bought himself a compressor and spraygun kit so it was a good first try-out – and the results are excellent.
The tank had a big dent in the top and the bodywork was faded, so it was time for fresh paint here too. Mark took charge of initial prep on the tank, using the technique of drilling a small hole in the dent and, with a tap, pulling the dent out. Another mate who’s a car paint specialist then set about the rest of the dents and the final prep.

The guys are pleased to say that no filler has been used in the tank’s restoration and said mate did a good job in matching the Candy Blue (metallic at that). Mark then sourced aftermarket-supplied stripes and transfers which he applied himself (the secret is to use a fine mist of water to help position the stripes, then let them dry into place). As yet, the tank and panels haven’t been lacquered but this will come.

A non-functioning tacho also proved problematic to fix. “We ended up buying three sets of clocks off eBay,” says Chris. “The problem was that while these can all look identical, different models have different internals, so it was a case of picking parts from all three. Even so it’s not right and while the tacho seems calibrated correctly it’s not reading past 6000rpm. It’s on our list to fix.”
They had better luck with the speedo. Converting to a mph clock, they used that old 1980s car dealer scam of turning the dials to put the mileage to the exact equivalent of the kilometres found on the original. The wiring loom was complete and essentially sound, so has been left alone (wise policy).
Elsewhere the restoration has been a matter of cleaning and replacement. All the bearings in the frame and swingarm were replaced. New pads and shoes went into the refurbished brakes – the hydraulic hose remains as original. The wheels came clean with some fine wire wool. The paint on the italic spokes is original.
From start (in November 2014) to finish was just four months, but as Chris explained that was two guys working two or three nights a week, plus weekends. There were a lot of hours. But as Chris also said, it was a nice simple restoration, and a great first resto for Mark. The finish is intentionally not to a show-winning standard – this is a rider.
The spirit of the resto is perhaps best reflected in the addition of a new Gibson-made Allspeed pipe. The resto didn’t need it, but Mark remembers Allspeeds from back in the day and this was how he’d have modded an RD125LC if he’d bought one then. It would have blown the budget, of course, but wife Emma bought it for him, having long-since recognised the significance of this bike to her other half.
“I’m indebted to Chris,” says Mark. “I’ve got the bike I always wanted but I’ve also had the enjoyment of seeing it come together stage by stage, and that makes it even more special. I’ll never get rid of it.”
Just to prove it, Mark has put over 650 miles on the RD over the past year – even riding to the May Day run under his own steam. He’s not got his full licence as yet, but he takes the theory in a few weeks time and the direct access is booked in straight after that. Then, given that the RD is a keeper, it’ll soon be snuggled up next to a VFR800, or maybe a Thundercat. Mark’s not sure yet, but one thing is certain: after a 26-year hiatus, he’s well and truly got the bike bug.

The ride

The RD125LC doesn’t seem much of a bike for bottom-end plonk – in fact it feels properly stifled for the first 4000rpm. But 4000rpm marks the point at which the RD first gets a whiff of impending freedom, and at somewhere around 5-6000rpm it hooks into its powerband good and proper, doing a fair impersonation of a little monster jumping out of your hands. So you need to keep your wits about you and make sure you grab second and third gears in quick succession, working to keep the RD in that powerband. You’re looking left and right for pedestrian appreciation, and as the chromed-spannie screams your presence you’re also watching the tailgate of the Mondeo in front, should the sudden rise in velocity diminish the following-distance too quickly. Then you catch sight of the speedo – 28mph...

Honestly, 28mph? It felt like 48 at least. But this is the attraction of these small capacity two-strokes – you’re getting almost the same thrill as the big boys, only at speeds that’ll make the fuzz laugh rather than prosecute. That said, I find the road sports 125s more difficult to ride than their sibling trail options. It’s hard to turn down the rider inputs;
I feel ham-fisted, over-clubbed on every action – and attempting to hustle the RD through a sweeper on these skinny tyres feels skittish. It doesn’t feel like there’s much holding you there. Barely 30mph and at about 15 degrees of lean, I’m on the edge.

It’s all fun, in its own youthful way. The motor in this RD is running so sweet, and being a Swedish import it’s a full-power unit of about 20bhp, so that makes it really nice, and much more useful and practical than the 12bhp spec UK riders would’ve been handed back in the day. The suspension works in a manner halfway between Öhlins plush and Mobylette crap – perhaps a little more than halfway to the Moby if we’re honest. The brakes work as ’80s brakes did – better than those of the ’70s, but nothing like we have now. And on this example they work exactly to spec: the front disc and single-piston caliper feeling spongy and gentle, while fortunately a bit of concerted pressure on the rear drum makes the whole job acceptable.

I like the fact that it’s a proper Yamaha RD as well. It’s sporting the tank stripes that the bigger LCs had, and there’s that same unique mixture of decent performance levels and decent build quality. It doesn’t ooze class – instead it shouts fun. It’s a working class hero, for the apprentice. It stuck two fingers up at the establishment back at a time when the law thought, for once, that they’d got the upper hand. It might have been only half a 250LC, but the same applies now as it did then: better to have half than none.

Thanks to:
• Chris for his friendship and for steering Mark through this rebuild
• Wife Emma and Chris’s wife Paula for allowing the lads to disappear into the man cave for hours and days on end
• Gibson Exhausts (01708 372122) for making the Allspeed pipe to order
• Jason at JDM Powdertech in Rochester (01634 723444)
• Mick at MA Coachworks in Lidsing, Kent (01634 232424) for the paint
• Bob for the bike


Specification | 1983 Yamaha RD125LC
ENGINE Type liquid-cooled, reed-valve, single-cylinder two-stroke Capacity 123cc Bore x stroke 56 x 50mm Compression ratio 6.8:1 Ignition 12V, CDI Carburation 1 x Mikuni VM24SS

TRANSMISSION Primary/final drive gear/chain Clutch wet, multiplate Gearbox 6-speed

CHASSIS Frame steel, cradle-type Front suspension 32mm telescopic fork Rear suspension ‘Monocross’ monoshock Front brake 1 x 220mm disc, single-piston caliper Rear brake 1 x 130mm SLS drum Wheels cast aluminium with italic-styled spokes Front tyre 2.75x18 Rear tyre 3.00x18

DIMENSIONS Dry weight 97kg Wheelbase 1300mm Seat height 775mm Fuel capacity 13 litres (1.9gals)

PERFORMANCE Top speed 70/90mph (restricted/unrestricted) Claimed power 12/20bhp@7500/9500rpm Claimed torque 8.7/10.8lb.ft@7000/8500rpm
Fuel consumption 64mpg Price new £850

Words Jonathan Bentman   Photos Stuart Collins

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Practical Sportsbikes

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Buying, owning and modifying the best bikes of the 80s, 90s & 00s