YAMAHA TZR125 FIZZY

YAMAHA TZR125 FIZZY

by Bauer Xcel |

WHEN HE WAS 17, DAVE GREENWOOD HAD A BASH AT PUTTING A 125CC ENGINE IN AN FS1-E. NOW, 33 YEARS LATER, HE’S COME BACK TO DO THE JOB PROPERLY

YAMAHA TZR125 FIZZY

Had PS been around in 1983, we might well have done a Special Brew on Dave Greenwood’s first Fizzy. As a 17-year-old, he’d found the diddy moped woefully underpowered, and rectified this lack of horses by fitting it with a Yamaha RS125 engine – taking it from 4.8bhp to 15bhp in one bold piece of slightly ‘industrial’ mechanical surgery. But once a fettler, always a fettler. Fast forward nearly 30 years and despite owning a Triumph Street Triple with all its fancy gadgets and mod-cons, Dave couldn’t get Fizzies out of his mind. “The call of that first bike I had as a teenager was too strong,” he smiles. “I just love the shape – there’s something so joyous about it. I knew I had to do another one.” So Dave found himself in the slightly unusual position of doing a second take on the first bike he ever modified – with the major benefit of having acquired a load more experience on bikes in the intervening years.

The first port of call must’ve been to buy a donor Fizzy then, right? “I actually bought a 1990 Yamaha YB100 frame – it’s virtually identical to the FS1-E frame and all the Fizzy parts fit onto it, but they made the YB100 into the ’90s as well so you can get more recent stuff that’s easier to find.” The key part of the project was getting the UK-spec, 1991 TZR125 2RH engine Dave had acquired to slot into the frame, and the process started in a rather unscientific, suck-it-and-see way. “I put the engine in to start with to see how far out it was going to be, but the two engine mounts at the back lined up pretty much straight away – that gave me a really good start. “From there I needed to address the rear of the head, which has a mounting, and a mounting for the front to go on the two downtubes for the TZR125 engine.

The logical step was to get the two downbars for a TZR125, which had the engine mounting brackets for the front arm, and then graft them into the frame around the engine “The downtubes go underneath the engine and meet the frame at the back, so I just needed to bolt the cradle to the engine and then take off enough at the top so I could create a bracket to the frame, and take off enough at the back so it could be mounted to the frame there. Then it was in. There wasn’t loads of intricate measuring or anything – I just used a ruler.” Like many restorers, Dave makes complex and fiddly engineering sound as though it has the same level of technical expertise as making a cup of tea. “Seriously, it was surprisingly easy,” he says. “There was a bit of welding, drilling and hack sawing, but nothing that tricky. You’d be amazed at how a lot of stuff that shouldn’t fit actually goes on pretty well. I don’t know if it’s to do with mass production, but if you stick to the same manufacturer there are a lot of points on different bikes that will line up and work.

YAMAHA TZR125 FIZZY

WHEELS

The front-end provided further examples of the uncanny way that Dave’s assortment of Yamaha parts somehow blended seamlessly together. “The TZR125 front wheel fitted in the YBR125 forks nearly perfectly – I had to have some spacers made but then it went straight in. “The back wheel was the same – just some new spacers and it was sorted. The TZR125 rear wheel is a lot wider than a Fizzy-sized one and I wondered if it would fit, but the YBR125 also has a wider wheel so you’ve got the clearance there. There’s always luck involved in a project like this, though...”

YAMAHA TZR125 FIZZY

BRAKES

“The brakes are off a 4DL, the full-power Italian TZR125,” explains Dave. “Yamaha actually used the same brakes for that bike that were on the old TZR250. I thought that if they could stop a bigger bike with the same engine, then they’d be fine for this bike. Let’s face it, they could hardly be any worse than Fizzy brakes, could they? “I just needed to get different spacers and they went straight on. All I did was make a cardboard template to match up with the two lugs on the fork, put the caliper on, get it as near as possible to the two lugs on the fork and then get the template made out of 4mm steel.”

SWINGARM

“This YBR125 swingarm is slightly longer than the one on the YB100,” says Dave. “I chose it because the back wheel needed to be further away from the pivot point, as with all the power I’d have with that new wheelbase the bike would be wheelying all the time. “The swingarm wasn’t particularly hard to fit. The only thing was that the Yamaha YBR125 had a monoshock, so to keep the twin shocks two steel plates had to be welded on to take them. I just took a cardboard cut-out down to my local engineers and said, ‘Could you make a couple of these out of 8mm steel please?’ £40 later, it was job done.”

YAMAHA TZR125 FIZZY

SHOCKING LACK OF KNOWLEDGE

Restorers usually have an anal knowledge of everything on their bike... well, most of the time. “I don’t know what bike thes rear shocks are off,” ’fesses Dave. “They’re just piggyback shocks off eBay, which were the right length at 375mm.”

YAMAHA TZR125 FIZZY

THE RADIATOR’S ON

“All I needed to do to fit the TZR125 radiator was weld a couple of lugs on – everything had to be moved as the radiator’s in a different place on a TZR. Once I’d shifted the cradles it fitted fine and the hoses weren’t a problem, either.”

YAMAHA TZR125 FIZZY

MUDGUARD GETS THE CHOP

“Because of the length of the swingarm, I found that I couldn’t get an off-the-shelf mudguard to work. So I dispensed with the mudguard, cut the end off and put that into the back of the frame to make it look right. I’m happy with the results.”

YAMAHA TZR125 FIZZY

“The fake Fizzy airbox houses the powervalve controller”

So what about the classic Fizzy airbox on the side of the bike? This is where Dave satisfyingly reveals the most ingenious touch of the whole build. “Well, the cylindrical airbox with two chrome caps is not actually a Fizzy airbox – it’s a piece of rolled steel designed to look like one, made to the exact specifications of a Fizzy airbox. The air filter is actually inside the frame behind the side panels. I’ve used this ‘new airbox’ to house the powervalve controller – on the left-hand side of the bike you can actually see the two powervalve cables going into the box. “I did it because the Fizzy airbox is so synonymous with the bike and one of the first things you notice, so I thought that if it wasn’t there I’d really have something missing. It’s also part of the rear engine mount for the head, which is why it’s made out of 1.5mmthick steel. It’s structural as well as cosmetic.”

It wouldn’t be a proper Special Brew without a bit of head-scratching, of course, and so it proved with the wiring loom. “It’s a TZR125 loom and switchgear, and fitting it wasn’t that difficult to be honest. I had to shorten a lot of the wires because this bike’s a lot shorter than a TZR125, but the wiring goes inside the frame and it was all good. But when it was all fitted I couldn’t get a spark from the CDI, and it turned out it was because I didn’t have a sidestand switch, whereas a TZR would. “I contacted a guy on a forum and he said, ‘Have you earthed the blue wire off the TZR box?’ I said, ‘No, I don’t know what it goes to.’ He told me it earths through the sidestand switch – in other words, it thinks you’ve got the sidestand down and therefore it’s breaking the earth on that wire and won’t start. Once I’d earthed it, the bike thinks the sidestand’s up and it worked.” Having fired it up, it was time to ride it – so what was it like? “It went great but it was still so slow,” laughs Dave.

YAMAHA TZR125 FIZZY

“I suppose it shows that while you love the bike of your youth, they’re not everything you remember them to be. I soon got offered a TZR125 4DL engine, which is double the horsepower and more or less an identical fit – I put that in and hardly had to modify anything because the hard work had already been done.”Now packing a dyno-tested 24.3bhp and capable of 112mph, Dave has finally nailed the 125cc Fizzy. “When I first rode it with the 4DL engine in, it was beautiful. No wobbling or vibrations – it just sticks and goes. When I put that RS125 engine in my Fizzy all those years ago it buzzed like mad and felt a bit unstable – but this one doesn’t.”

So here it is – a Special Brew finally done properly, 33 years after the first attempt. “I suppose it shows that good things come to those who wait,” smiles Dave. “And let’s face it, a 50-year-old’s going to do a better job of making a bike than a 17-year-old...”

SPECIFICATION

YAMAHA TZR125 4DL FIZZY

YAMAHA TZR125 FIZZY

ENGINE 1991 TZR125 4DL, liquid-cooled, twostroke, reed-valve single with YPVS, 32mm Dell’Orto VHSA32 carb, bespoke Mick Abbey exhaust system, TZR125 wiring loom CHASSIS YBR125 forks, YB100 headstock, 1998 YBR125 swingarm, TZR125 4DL brakes consistingof 320mm front disc with Brembo four-pot caliper and 170mm rear disc with Brembo twopot caliper, TZR125 wheels with modified spacers, piggyback rear shocks, FS1-E fuel tank, FS1-E indicators, FS1-E indicators, FS1-E headlight

FUEL TANK “This was the luckiest find of the whole build. I bought it off a bloke on eBay – it had never been used and even came in the brand new NOS box. He only wanted £100 for it – you could sell it for five times that. I was just in the right place at the right time.”

EXHAUST “Initially I fitted a TZR125 exhaust, which was OK. But then I took it to Mick Abbey (mickabbeytuning.co.uk) and he developed a really cool pipe for it. Even a policeman came up to me the other day and said, ‘Nice exhaust, mate.’”

WORDS HANS SEEBERG PHOTOGRAPHY JASON CRITCHELL

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