THE ORIGINAL HAND BUILT HERO
Takazumi Katayama’s 350-3
This is the bike on whichtakazumi Katayama became the first Japanese rider to win a world title in any class. That fact alone makes it epic.
It’s not often in racing that the Japanese manufacturers get wrong-footed by their European adversaries – but that’s exactly what happened to Yamaha in both the 250cc and 350cc GPS in the mid1970s, courtesy of Harley-davidson’s Italian affiliate, Aermacchi. The American/italian crew had regained dominance of 250cc Grand Prix racing, having won four world championships in a row in the early Seventies, and then matching this with a pair of 350cc crowns in 1974/75 courtesy of Agostini and Cecotto. Yamaha had no answer to the relentless, empirical development of the Italian twostoke twins. This allowed Walter Villa to win a hat-trick of 250cc world titles in 1974-76, culminating in a pair of championships in 1976 when he turned the stroked Harley-davidson RR350 into a title winner, alongside the RR250 which gave birth to it. Yamaha’s factory engineers, then concentrating on trying to regain the even more prestigious 500GP crown which Suzuki and Barry Sheene had wrested from them that same year, had no answer to this combination of Italian ingenuity backed up by American money, a fact which was not at all appreciated at the Japanese firm’s European HQ in Amsterdam, the base for the company’s Grand Prix race effort. In the entire 1976 season, no less than 34 out of the 37 points-scorers in GP racing’s 250cc class were Yamaha-mounted, and 35 out of 39 in the 350cc category – but in truth this was of little consolation. Yamaha Europe wanted to win championships, not just score brownie points with their customers for producing the Manx Norton of the two-stroke era.
Begin the ‘Special’
The idea of resolving this situation in the 350cc class by constructing what amounted to a works special created out of one-and-ahalf TZ250S came about in an unlikely way. Swiss sidecar driver Rudi Kurth was the man who had the idea first, using a self-built three-cylinder Yamaha-based engine. This was basically derived from sticking an extra cylinder onto a TZ350 motor, and reducing the stroke from the standard 64mm of the 350 to 51.8mm, to create a lightweight 500cc package which was pretty competitive, if not very reliable. Still, the CAT-3 gave Dutch engineer Ferry Brouwer the idea of doing something similar, but for solo use. Formerly Phil Read’s mechanic on the works 125/250cc V4 Yamahas which won him a controversial pair of world titles in 1968, Brouwer was also the man who built and maintained the privateer Yamaha twin on which Read defeated Rod Gould’s works Yam to win the 250cc crown in 1971. “In 1974 I was working in a Dutch bike dealership, well away from road racing,” recalls Ferry, today best known as the former boss of Arai Europe, later the patron of the Yamaha Classic Team. “But I still had close contacts with Yamaha Europe, and especially with their technical director, Minoru Tanaka, who had been the factory race engineer in charge of the V4 projects, and was now in charge of racing for Yamaha NV. “He heard about the Kurth three-cylinder engine, and had the idea of making a solo 500cc racer with it – so he hired me back to Yamaha to construct it for him, and we went to Switzerland and bought some crankcases from Rudi. “With these I built the first 500cc triple in a standard Yamaha frame – we made four of them altogether, and they eventually produced 98bhp at the rear wheel, which compares very well with the straight 80bhp of the OW19 four-cylinder which Jarno Saarinen rode in 1973, as well as weighing 4kg less! “But then we had the idea to make a 350 as well, so Tanaka-san ordered some TD2 crankshafts from Japan, and we made the first 350 triple. We ran it with a standard frame in a couple of Dutch races in 1976 with Kees van der Kruys, the former Dutch champion riding it, and we quickly realised this was something we could win the world championship with.”
A total of five engines and two complete bikes were built in Yamaha’s workshops near Schiphol Airport, with the motors measuring 54 x 50.2mm for a capacity of 345cc, each comprising a Kurth crankcase fitted with a specially-made Hoeckle crank carrying TZ 250 rods and pistons, and a fourtransfer TZ250 cylinder block with individual Yamaha Y hhd heads, to t which hi h an extra t cylinder li d was welded on to the left side. A process which took some skill, employing a special welding technique developed by Kurth to prevent distortion. This lopsided arrangement meant that, even after the stock TZ350 chassis the prototype engine was originally fitted in was discarded in favour of the Bakker/spondon frames, f the th bik bike still till had h d the th engine i offset ff t to the left, a fact visually confirmed by the big dimple in the fairing. That, in turn, meant the riders had to be careful not to scrape the specially-made Kröber ignition on left-handers. Standard Yamaha factory exhausts were fitted, with the header for the added-on left-hand cylinder performing a serpentine twist to run up the centre of the bellypan between the other two, but this itself was no guarantee t of f performance. f “Mr Tanaka ordered 50 sets of TZ250 exhausts from Japan,” says Ferry: “And there was a 7bhp difference between the best and worst of these – more than 15% of power on a 250! We made sure we only used the best.” 34mm Mikuni carbs were employed – Lectron flatslides were also experimented with, but jettisoned because they made the bike hard to fire up in those pushstart GP days, and also because their sudden power delivery exacerbated what was already a difficult bike to ride, especially in the wet, thanks to its peaky engine. It might have been peaky, but right from the very beginning, it was extremely fast.
Time to shine
The TZ350-3’S debut in Katayama’s hands at Belgium’s ultra-quick Mettet circuit in April 1977 proved that beyond doubt. There, the Japanese rider finished third in the 500cc race on his 350 triple, behind a pair of RG500 Suzukis – but ahead of many others, and leaving all the TZ350 twins in his wake, despite d it having h i t to stop t t to change h plugs l after ft a first lap misfire. After missing the first GP of the season in Venezuela owing to the new bike not being completed, the team was eager to start playing catch-up a week after Mettet at the second round on the fast Salzburgring track – only for Katayama to crash in practice after qualifying third, and take to the grid aboard a hastily-repaired machine that wasn’t running right. But after second-placed man Franco Uncini slid off his works Harley and triggered a multi-bike crash that sadly led to the death of Hans Stadelmann, the race was abandoned with no points awarded. So the Yamaha triple’s first proper GP race was the following week at Hockenheim, a circuit even better suited to the speed missile it seemed to be. There, after a slow start Katayama swept past the two leading TZ350 twins of South African brothers-in-law Alan North and Jon Ekerold as if they were 250s, to go on to win by 15 seconds from team-mate Agostini. He H hdb had been last l t away on the th sister it ti triple, lbt but repeatedly smashed the lap record on his ride through the field, eventually establishing a new mark 2.5 seconds faster than the old one. A 1-2 finish in the TZ350-3’S first GP was proof that Brouwer and Tanaka had had the right idea, though third place the following week in the Italian GP at Imola revealed that all was not perfect in the handling department, with the extra bulk of the three-cylinder engine making the Yamaha less adept at changing direction quickly than its twin-cylinder sister. Ago especially complained about this from the outset, and insisted on using the factory TZ350 twin left vacant by Cecotto’s broken arm sustainedined in the Salzburgring S lb i pile- up, for qualifying at Imola, before Yamaha NV bosses enforced hish return to the triple for the race, in which he retired early with a seizure.
The switchback Jarama circuit was even less suited to the triple, but Katayama captured another third-place finish in the hourplus 38-lap Spanish GP marathon (even more creditable after winning the 35-lap 250cc Spanish GP earlier in the day!) to take over the lead in the world championship points table for the first time. Agostini qualified 18th, DNF once more, and indeed would never again score points in a 350cc GP race. By contrast, Katayama’s grasp on the world title was further strengthened by victory next time out in the French GP at Paul Ricard, where he led from start to finish to win by 24 secs. from Ekerold, and set a new lap record in a race entirely populated by Yamaha riders – Harley had given up trying to defend its 350cc title in the face of the new Yamaha triple’s evident superiority, and retrenched to take care of 250 business (unsuccessfully, as it happened – Mario Lega won the title for Morbidelli). This was an especially satisfying result for tuner and team manager Kent Andersson: “I’d been working for two weeks back in Amsterdam to improve the engine – always at night, otherwise half of Holland would know what we were doing!” said Kent. “I flew down to Ricard with new cylinders, heads, pistons and pipes, removed what was left on from the week before at Jarama, and Katayama was quite pleased with the result –- he had 17kph more top speed down the Mistral straight than the TZ twins, and broke the existing 500cc lap record four times in the 350 race! The Japanese from Yamaha were coming up to me saying, please Kent-san, stop him going so fast – so I said, well, I’ll see what I can do. “I went to the pit wall and looked at him, and all I could see was this huge smile behind the visor! So I said to them, no, I’m not going to stop him – he’s having the time of his life and he’s going to win the world championship! That was the day we knew we had what we needed to do that.” But a crash at the non-championship race at Chimay in Belgium the following week threatened to derail Takazumi’s title hopes, though the broken collarbone he suffered there was plated to let him race just seven days later in the Yugoslav GP on the tortuous and dangerous Opatija circuit. There, after opting to race a TZ350 twin on the grounds that it was lighter-handling and easier-starting, he amazingly won the gruelling 25-lapper by over half a minute from Ekerold, after finishing second in the 250cc GP to Lega, and having to push-start both bikes with his bust collarbone, getting away well down each time as a result. True grit. After retiring from the Dutch TT at Assen with gearbox troubles while lying fourth, Katayama rode the triple to victory again in the Swedish GP at Anderstorp, after coming off best out of a last-corner confrontation with Kork Ballington – which led to widespread muttering about the Japanese rider’s somewhat committed riding style which earned him his ‘Kamikaze‘ nickname. But still, it was a coolly calculated one, as evidenced by Katayama’s skill on, even liking for, public roads circuits like the venue of the following week’s Finnish GP at Imatra. There, he became the first Japanese rider ever to win a world championship in any class, when he scored his fifth victory in eight GP races that season to clinch the 350cc title two rounds early, overhauling early race leaders Tom Herron and Jon Ekerold when rain started falling, to take a convincing win – on slick tyres! Even after sitting out the final two rounds at Brno and Silverstone, Katayama and the Yamaha triple still won the championship with almost double the points score of series runner-up Tom Herron – so instead of a GP send-off, the title-winning TZ350-3’S final race in 1977 was on the Hilvarenbeek street circuit in Holland where, fitted for the first time with White Power suspension, it duly won.