Yamaha RZ125FN: The little single that could have been
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Yamaha RZ125FN: The little single that could have been

By JeffWare - 24 August 2022

Words & Pics: Jeff Ware

Covid-19 brought with it many challenges for all of us and one far too common story I hear, being in the industry I am, is the dreaded, “I sold my bike(s) to keep the money flowing” story… Sadly, just like many people, I was not immune to this issue and with four kids, huge school fees, a business (BikeReview.com.au) and employees to keep in food and home (and job) a whole bunch of my private bike collection went out the door too. I regret selling many of them, and one was my beloved 1985 Yamaha RZ125FN…

The 1295mm wheelbase and 98kg weight made the RZ o so nimble and fun to ride!

RZ125? I hear you ask… You mean a 250 or 350, right? I must admit, even I was questioning the ad in the Trading Post, back in winter of 2000. I was 25-years-young and a motorcycle courier in Sydney. I’d previously owned an RZ250 and assumed this was a 250, with a typo in the ad. I was shocked when I arrived to find a single-cylinder 125! “What the hell is this”?

Turns out the owner was South African, and the bike was a South African import. It was so cute. Red and white, proper Yamaha racing colours, with all the curves and features of the 250 and 350, right down to the alloy wheels. I had to have it and $1600 late I was riding home from Lane Cove to Arncliffe on a freezing night on the peakiest bike I’d ever ridden, with Heather following me in the car. I had a huge grin on my face. It was the start of a 20-year love affair with the little rocket…

Over the next 12-months I just about took the bike around the clock riding as a courier, before I started my career in mid 2001 as a Staff Journalist at Two Wheels magazine. I still rode it to work, and I rode it as much as possible for the next 19-years. It had 112,000km on it when I sold it. Or I think it did. And I never touched the engine, not even a piston ring set. Just services, tyres, chain and sprockets. Not even a clutch! It was completely bullet-proof and the most reliable motorcycle I have ever owned. I did 10-hour courier days on it rain, hail or shine and it never let me down and always started first kick.

50mm x 56mm bore x stroke is the Yamaha secret number that gives a good torque and hp spread for a stroker. A brilliant engine, also used in the Yamaha DT125 of the era.

I sold it to a gentleman who was so, so excited to buy it that it really made it less painful to part with. He had owned one when he was younger and was looking forward to restoring the bike. Sometime after taking delivery, he sent me images of the finished product and I was so happy to see my old RZ restored that I cracked a few beers and went through my old photos of the bike. It was one of those bikes that never leaves the memory bank… And I’m sure it is the Yamaha that “Could have been" for the Australian learner and commuter market. It would have been a very popular model here, with a long life…

I had RD250LC chrome aftermarket handlebars on my bike. I just loved the riding position. 

In the UK it was known as the RD125LC and was extremely popular. There is also a 50cc version in some markets, and the goal for me is to have one day a 50, 80, 125, 250, 350 and 500cc RZ in the collection. I’m talking Tamiya models of course!

The RZ125 had a centre-stand for practical reasons, and was just such a stylish bike, it would have been a hit here. 

The RZ125 was a basic bike but very sporty and high performance, with a dry weight of just 98kg and with 20hp from the screaming single-cylinder two-stroke, it was a peaky bugger, with no YPVS back then. Carburetion was via a small Mikuni round slide carby, while the expansion chamber was the older Yamaha style like the 1983 RZ models, before the polished alloy mufflers arrived on the FN.

Large 17L fuel tank and like all RZ models, a huge and comfy seat. It was a great all-day bike. 

The forks are tiny little 32mm items, while out the back is the early version on the Monocross system, with a basic shock. Brakes are adequate without being sensational, a drum rear and a small 245mm front rotor. They do the job, but the front disc is bad in the rain as it is not ventilated.

The RZ125 is kick start and runs a 6V electrical system for the lighting, indicators, warning lights and horn. The clutch is a cable actuated wet multi-plate unit that is featherweight in action and very smooth to operate, while top-end lubrication is via the Yamaha Autolube system. Gearbox oil is separate.

Plenty of storage under the seat, 6V battery system, foam oil airfilter, large airbox.

Like all RZ models, the 125 is roomy and has a broad, comfy seat with ample storage, lots of room for a pillion, rubber footpegs for comfort, an upright riding position and a large fuel tank. Overall, a brilliant little machine with fun performance!

The 245mm front rotor was just good enough but not the best in wet weather. Check out the little forks and the sweet front wheel design.  


Engine – Two-stroke liquid-cooled single-cylinder, 56mm x 50mm bore x stroke, 123cc, 6.4:1 compression, Autolube oil-injection system, 1.1L oil tank, Hitachi CDI ignition, 24mm Mikuni carburettor, kick start, six-speed constant mesh gearbox, wet multi-plate clutch with cable actuation, foam oil airfilter, 6V battery.

Chassis – Steel backbone frame with Monocross link rear suspension, six-step rear preload adjustment, 32mm forks, single front 245mm rotor, 130mm rear drum brake, 428 chain, 2.75 x 18in front tyre, 3.00 x 18in rear tyre, 1295mm wheelbase, 775mm seat height, 185mm ground clearance, 1990mm wheelbase, 735mm width, 1190mm height, 13L fuel tank.

Performance – 20hp/15.5kW@9500rpm, 16Nm@9250rpm, 98kg dry weight.

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