Takazumi Katayama’s 350-3

Classic Racer - - FRONT PAGE - Words: Alan Cath­cart Photo: Ky­oichi Naka­mura

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.

Kurth­side­car en­gine.

Rudi Kurt­hand Dane Rowe,1972.

Katayama at Fuji Race­way,ja­pan.

Katayama and Kel 1972. Car­ruthers in Ja­pan,

Above: Kent An­der­s­son. Right: Ferry Brouwer.

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