YAMAHA YZR500
With work on it finished, we had to do a photo shoot on Niall Mackenzie’s beautifully restored YZR500 – and look at the machine’s bloodline.
Niall Mackenzie on his awesome 500cc GP bike: the ultimate LC!
Every factory race bike is effectively a handbuilt special so by nature they can sometimes be quite rough around the edges. Many would say that is part of their character and I’d agree, however, the OCD racer in me (we’re all riddled with it) likes to tidy things up so this is what I decided to do. Don't you think she's beautiful?
Firstly, the finish on my YZR frame and swingarm was inconsistent, some being part polished, some part scuffed, due to the occasional gravel trap excursion. Personally, I don’t like the super shiny look so after some trial and error we found the perfect grade of wet and dry paper for the job. Too rough was scratchy and too smooth made no impression, so we eventually settled on P1000 grade paper. It took a few hours, but very satisfying blitzing everything to a uniform original brushed aluminium finish. We then repeated the same process on all four Millet Racing expansion pipe exhausts.
One thing I do love about older race bikes is their minimalist electrics. The wiring harness only has to take care of four ignition coils, the electronic powervalves, a kill switch, rev-counter, temperature gauge and total loss battery. Although out of sight, over the years everything had become scruffy so we replaced connectors, re-soldered and re-insulated where necessary. As with most race bikes back in the day it all operates on a total loss system, but with a rechargeable battery for operating the powervalves. We had to replace the inner powervalve cables that were frayed due to wear and tear. The two-into-four throttle cables and clutch cable still appeared as good as new.
Radiators for these machines were all hand-made and spares simply don’t exist now so I count myself fortunate mine is still totally intact and leak-free. After a good hot parts wash and thorough flush through, a good hour was spent picking the fins straight whilst removing any leftover debris. I swear I recognized some Le Mans pea gravel in there from 1991!
We hired Larry at Illusion Racepaint in Northants to do his stuff with all the paintwork. His tasks included removing a tank dent and sourcing all the period decals from my 1991 season, plus repainting and pin-striping both 17-inch Marchesini wheels.
As with the tank and bodywork, they returned with a sheen and finish that probably wouldn’t have been possible 29 years ago. Understandably, the bodywork on race bikes actively involved in racing only ever had a blast of primer and one coat of colour as said parts would inevitably (and quickly) become spectators’ souvenirs.
Also, anything unseen would normally be bare fiberglass, so it feels good to finish the job off with
every surface painted properly. Twice as heavy mind, but no one is watching weight these days.
My bike was originally delivered with 290mm carbon discs which is fantastic. However, no one really knows if this material can stand the test of time. Some experts claim they’ll last forever and some say they’ll eventually crumble. I decided to avoid any unexpected dramas and bite the financial bullet, investing in new 320mm steel Brembo rotors. Not cheap, and they don’t look quite as cool, but I believe a worthwhile investment if they stop me launching my pride and joy. We used these bigger discs in wet conditions back in the day so the forks are already fitted with alternative brake caliper mounts. Just for good measure I also replaced the three-decade-old brake lines and plastic shrouds, and I’ve swapped the ancient Michelin rubber with new Michelin Power Slick Evos. These modern track day tyres are light years ahead of what we raced on in 1991, but more importantly a whole lot safer than the crusty relics I’d been using.
Come assembly time and it was time to take direction from Daryll from IDP Moto. As always, we started by laying every nut, bolt and component out in order and in sequence of assembly; a simple method and I still get embarrassed thinking how long my randomly digging around in boxes re-building a system used to take!
With a brand new clutch and refreshed top-end, we first slotted in the compact V4 motor. A straightforward job and being magnesium it is, of course, as lightweight as James Whitham’s wallet. Next up were the rolling chassis parts: swingarm, sub-frame, headstock, the fully serviced front and rear suspension and handlebars. Thankfully, every bearing, bush and spacer has remained in a perfect unmolested condition so aside from cleaning and lubing, this part of the re-build was straightforward.
Then it was on to carefully routing and neatly fastening the electrics, followed by the front and rear brake calipers and lines. We then mounted the powervalve motor and carbs, and fitted the associated cables. Considering the bike had been sat around for a few years, the carbs were only slightly gummy so a thorough contact clean, blow through plus mechanism check saw them in pristine condition and good to go. I hear these carbs alone cost £18,000: that’s mental!
With all the handlebar controls in place we then mounted the simple rev-counter/temp gauge dash, radiator and hoses, and lastly both side foot-rest hangers and levers.
With only the tank and bodywork left to fit, we
st tood back for a moment to admire this amazing bi ike in all its naked glory. Its minimal raw ph hysique always reminds me of a superbly honed, muscular m athlete primed and ready to perform: dr rug free, of course. Another 15 minutes saw the tank and bodywork fitted, completing our job.
Little details take me back in time, like the Ohlins top yoke preload adjuster (I never did use it) and the Ermax screen supplied by this lovely French family company who, I noted, happened to be obsessed with Scotland. I’m also very proud this YZR carries the number ‘4’ from my best 500cc World Championship finish in 1990.
The total cost for this much-needed refresh was an eye-watering £7,500, but what price to have this immaculate icon I rode to the limit in an amazing era of 500cc Grand Prix racing? Having gone through everything with a fine toothcomb and sparing no expense, I know my bike is as perfect as any YZR 500 in existence. Offers on a postcard please.
Niall Mackenzie: Riding the YZR500…
My first experience of Yamaha’s YZR 500 was actually from an opponent’s perspective. I was a factory Honda rider on NSR 500s in 1987 and 1988 when the main men on the Yams were defending champ Eddie Lawson, Randy Mamola and the mad (but super-quick) Frenchman, Christian Sarron.
My Honda was always fast, but I struggled with front-end feel, making it difficult to make my ‘high corner speed 250 GP’ riding style work at the slower sections of some circuits. Lawson and Mamola could slide their bikes flat-track style when they wanted, but mostly they would use superior corner exit speed to stay with the Hondas on the faster straights. 1984 250cc world champ Sarron was the rider I could relate to most as he made his YZR look nimble, pushing the front everywhere to great effect. Yamaha appeared to run a stiffer chassis with steeper geometry and in my opinion the superior Ohlins suspension. Yamaha also ran a twin crank V4
motor that delivered a more user-friendly powerband compared to Honda’s single crank that revved harder but chimed in like a light switch. Their single crank motor also produced more gyroscopic forces, making the Honda less agile on direction change.
Over the years the manufacturers’ motors changed very little, although they would always find a few bhp over the winter for the following season. Engine development came from numerous areas. Compression changes from port heights, pistons, cylinder head mods along with exhausts, jetting and powervalve tuning were the main areas targeted for more performance and some teams tried different fuels. Cagiva being the most obvious and I remember one year they used the most pungent, toxic-smelling potion ever from Agip! The Yamaha would make good power from 10,000rpm to just over 12,000rpm and depending on jetting and exhaust spec, carry on to 12,750rpm. Over-rev was always important to keep your bike in the powerband, especially through the higher gears. The Honda had a 500rpm advantage everywhere, although they went mad in 1988 with a 14,000rpmplus motor. I loved it, but HRC couldn’t keep me or Gardner going in crankshafts. I had three DNFS while in the hunt for podiums that season, which killed my chance of a top three championship finish.
Incidentally, all four V4s sounded amazing, but distinctly different and I could still identify them today. The Honda was throaty, the Suzuki was raspy with clutch rattle, the Cagiva wailed, while the Yamaha had a real high-pitched scream.
My first ride on a YZR was a Phillip Island test when I signed for Marlboro Yamaha Agostini in 1989. My first impression was I sat more on top of the bike and as I suspected it did feel more nimble. It had more mid-range grunt than the Honda, but it fell on its face as it would run out of top rpm. I gradually gelled with the bike and my season progressed well, jumping on to the podium by round four in Jerez. I was on for 3rd at the abandoned Misano round before disaster struck at Hockenheim when I knackered my left knee, which once again killed my top three championship aspirations. I excelled at some tracks and struggled at others so the bottom line was, the riders that could figure it out every weekend took the spoils. Tracks like Suzuka, Donington, Laguna Seca, Misano and Jerez suited me and the YZR perfectly, but I lost out at others where Lawson, Rainey and Sarron were fast.
At that time I was on the Michelin ‘B’ list for tyres, which didn’t help, but the bottom line is it is down to the rider to make things happen. That’s not just fitness and skill, but good set up knowledge from carburation feel to gearbox ratios and suspension settings for maximising tyre life. If only I knew then what I know now!
After finishing 4th in the Championship on a Suzuki in 1990, I was back on a factory Yamaha for 1991 (this here bike) and 1992. Carbon brakes were a major step forward for everyone, but the big change for 1992 was the ‘big bang’ motor that Honda appeared with at the season opener in Japan. By mid-season the other factories had copied HRC, but the Honda was always superior. I received a motor for the British GP and loved it. However, a big-end failure once again cost me an easy podium.
I rode ROC Yamahas in 1993 and 94, finishing 9th and 10th respectively in the world championship. My private WCM Team used motors tuned by Harald Bartol and they were as fast as the factory boys when they held together. We had a great little team, but once again had a serious disadvantage when it came to getting the best tyres. In 1993 Wayne Rainey actually won in Barcelona on a ROC in disguise, proving just how good they were.
To sum up, anyone out there would enjoy riding a YZR 500.They are light and small, but have a roomy riding position and having a decent-sized motor, will pull away easily with the right gearing fitted. The tricky bit, however, is finding the tiny window that allows you to go fast without launching you to the moon. Being ahead of the game is key when racing two-strokes as you have to anticipate when the power will arrive at the rear wheel. The revs always start to build gradually, but when the aggressive power arrives you need to have decent rear contact as it is already too late to close the throttle.
I was lucky to still be riding YZR 500s as late as 1998. I was back racing full-time in the British Superbike Championship, but was also hired as the Red Bull WCM Yamaha test rider to help Simon Crafar and Regis Laconi. I rode pre-season in Phillip Island and Shah Alam, then at Paul Ricard and Brno in the summer. The bhp had increased, but the delivery and throttle feeling by then were super smooth. The Red Bull Team also had a basic traction control system that retarded the ignition when sensors recognised reduced traction. These bikes were a joy to ride, and being able to easily better my previous lap times at familiar circuits proved how far they had moved on.
Those 10 years for me were amazing and scary in equal measures, but I wouldn’t change my YZR adventures for the world!