Yamaha RD250E

‘The speedo nee­dle crept to­wards 140 km/h, the en­gine screamed, the scenery rushed by… and it was very easy to un­der­stand the phe­nom­e­nal sales suc­cess of Yamaha’s air-cooled, two-stroke par­al­lel twins’

Bike India - - CONTENTS - WORDS: ROLAND BROWN | PHO­TOG­RA­PHY: PHIL MAS­TERS

Roland’s take on the younger sib­ling of the leg­endary RD 350

SIM­PLY CATCH­ING SIGHT OF the very clean white-and-red RD250E had brought back a few mem­o­ries, and start­ing the en­gine re­ally trans­ported me back in time. The Yamaha fired up first kick with that rau­cous, clat­tery, off-beat rakkat­ack-tack of an ex­haust note from its twin pipes, along with a small cloud of two-stroke ex­haust smoke that pro­vided the per­fect, at­mos­phere-en­hanc­ing (and pol­lut­ing) ac­com­pa­ni­ment.

I’d been look­ing for­ward to rid­ing the RD250E all morn­ing, and now I was re­ally hooked. It’s a long time now since the late 1970s, when there were so many of them on the roads. But even now there’s some­thing about Yamaha’s cof­fin-tanked twin that seems to sum up all that was best and cra­zi­est about the days when, for teenage speed freaks on a pro­vi­sional li­cence, a hot Ja­panese 250-cc two-stroke like this was the height of mo­tor­cy­cling per­for­mance.

Ten min­utes later, its en­gine warmed and the road ahead clear, the Yamaha revved hard through the gears while I held its throt­tle wide open, slid back on the seat and crouched down to help make the high-han­dle­barred RD as aero­dy­nam­i­cally ef­fi­cient as pos­si­ble. The speedo nee­dle crept to­wards 140 km/h, the en­gine screamed, the scenery rushed by… and it was very easy to un­der­stand the phe­nom­e­nal sales suc­cess of Yamaha’s air-cooled, two-stroke par­al­lel twins.

This RD250E was reg­is­tered in 1980, the year that the RD250LC and its 350-cc sib­ling were un­veiled, be­gin­ning a new era for Yamaha’s twostroke road­sters. That was also the year King Kenny Roberts won his third straight 500-cc world cham­pi­onship, re­in­forc­ing the im­age of a two-stroke Yam with speed-block paint scheme as just about the fastest, snarli­est thing on two wheels. (Iron­i­cally, Kork Balling­ton and Kawasaki had by this time taken over the 250-cc class.)

The story of Yamaha’s twins had be­gun a long way be­fore that. This bike’s blood-line goes di­rectly back to 1957 and the YD-2, Yamaha’s first air-cooled two-stroke twin, which was de­vel­oped from the com­pany’s very first mo­tor­cy­cle, the 125-cc sin­gle-cylin­der YA-1 Red Dragon­fly of two years ear­lier. A few years later came the YDS-2, a more pow­er­ful and so­phis­ti­cated 250 twin that was un­leashed on ex­port mar­kets world­wide in the early 1960s.

Yamaha’s rep­u­ta­tion for fast and fu­ri­ous two-strokes was en­hanced by the firm’s grand prix suc­cess, no­tably in the 250-cc class, where Phil Read won three world cham­pi­onships in the 1960s. The world ti­tles kept com­ing into the ’70s, with Bri­tain’s Rod­ney Gould, Phil Read again, fly­ing Finn Jarno Saari­nen, and Ger­many’s Di­eter Braun con­tin­u­ing the run be­tween 1970 and ’73. In that year Yamaha re­named its new road­ster the RD250, the ini­tials stand­ing for Race De­vel­oped.

The first RD250A had the rounded petrol tank and drum front brake of its pre­de­ces­sors, but was pow­ered by a re­vised en­gine with di­men­sions of 54 x 54 mm, in­stead of 56 x 50 mm. It was also more com­pact, pro­duced a claimed 30 PS and had reed-valve in­duc­tion for the first time. “Fea­tur­ing ev­ery merit of Yamaha’s world GP proven tech­nolo­gies,” boasted the ad­ver­tis­ing blurb, with some jus­ti­fi­ca­tion. Cu­ri­ously, the new six-speed gear­box’s top ra­tio was blanked off in some mar­kets, in­clud­ing the UK. One mag­a­zine still quoted a top speed of 160 km/h, along with “shat­ter­ing ac­cel­er­a­tion”.

The ma­jor de­vel­op­ment came in 1976 with the RD250C which, along with its RD400C sib­ling, in­tro­duced a new, more an­gu­lar look, com­plete with cast wheels and sin­gle disc brake front and rear. The larger model’s en­gine was in­creased in ca­pac­ity from the old RD350. Although the RD250C re­tained its ca­pac­ity, changes in­clud­ing the use of 28-mm Mikuni carbs in place of the ear­lier 24-mm units in­creased peak out­put to 32 PS at 8,000 rpm. The 1979-model RD250E in­tro­duced elec­tronic ig­ni­tion plus a frame with re­vised foot-rest mount­ing, but in per­for­mance terms was essen­tially un­changed.

Which brings us to this very clean 250E, which ran su­perbly well, fir­ing up eas­ily, idling ef­fort­lessly, and tak­ing very lit­tle time to re­mind me just why the RD250 had such a great rep­u­ta­tion in its hey­day, even if it was slightly over­shad­owed fol­low­ing the in­tro­duc­tion of Suzuki’s slightly quicker GT250 X7 in 1978. The X7 was a sig­nif­i­cant 23 kg lighter

but the fact that the Yam — which shared its chas­sis with the 44-PS RD400 — was larger and more sub­stan­tial ar­guably made it a bet­ter road­ster. Es­pe­cially if, like me, you’re a lot big­ger and heav­ier than the av­er­age 17-year-old.

At 165 kg with a gal­lon of unleaded in that rec­tan­gu­lar tank, the RD250E was still a very light and ma­noeu­vrable ma­chine, which was partly why those 32 horses were able to make it seem so sat­is­fy­ingly quick. At low revs the reed-valve two-stroke ran cleanly and pulled well enough for easy ac­cel­er­a­tion in the lower gears, with­out the need for fran­tic revving when pulling away (un­less, of course, your mates were lined up along­side you at the lights).

Then at just be­fore 6,000 rpm the mo­tor reached its power-band and came alive, send­ing the bike surg­ing for­ward with enough en­thu­si­asm to put a smile on my face — and, no doubt, an even big­ger one on the spotty coun­te­nances of its youth­ful own­ers more than three decades ago. The ex­haust note hard­ened to a pleas­ingly racy two-stroke cry — far too loud to be le­gal these days — and the speedo nee­dle kept on mov­ing as I flicked through the six-speed box, which shifted nicely although this bike’s lever was set slightly too high for my lik­ing.

Mind­ful of this bike’s age, I backed off at an in­di­cated 140 km/h, but an RD250 was good for an in­di­cated 160 km/h when new, even if its true top speed — when mag­a­zines got round to ac­tu­ally mea­sur­ing such

The RD250E was much in de­mand by bike thieves and many oth­ers in its hey­day even if it was slightly over­shad­owed fol­low­ing the in­tro­duc­tion of Suzuki’s slightly quicker GT250 X7 in 1978

data, rather than es­ti­mat­ing — was less than spec­tac­u­lar, at about 150 km/h. Inevitably, the raised han­dle­bars meant high-speed cruis­ing soon be­came tir­ing, and prompted many own­ers to fit ace bars. The rub­ber-mounted foot-rests were fur­ther back than the pre­vi­ous model’s and, like the rub­ber-mounted pegs, did a good job of keep­ing the par­al­lel twin’s vi­bra­tion at bay.

The Yamaha’s ex­tra weight com­pared to the Suzuki X7 might have been a hand­i­cap in the heat of pro­duc­tion race bat­tle, but the more sub­stan­tial RD, which also had a longer wheel­base, was the more sta­ble han­dling of the two. Its chas­sis was iden­ti­cal to that of the slightly wheelie-prone RD400, and the 250 ben­e­fited from the frame strength and ge­om­e­try de­signed to con­tain the more pow­er­ful mo­tor. Even at high speed, with the wind flap­ping at my jacket and jeans, the Yam al­ways felt sta­ble and well con­trolled.

It han­dled pretty well at lower speeds, too, just as I re­mem­ber my old RD400C do­ing many years ago. The wide bars and nar­row Dun­lop K82 tyres gave plenty of agility, de­spite the 18-inch di­am­e­ter of the neat, seven-spoke al­loy wheels. This bike’s sus­pen­sion seemed to have sur­vived well (de­spite slightly pit­ted fork stan­chions, one of its very few cos­metic blem­ishes), and the ride was rea­son­ably firm, with none of the bouncy, un­der-damped feel I’d half ex­pected.

The Dun­lops had more than enough grip to use all the fairly gen­er­ous ground clear­ance, too, and would doubt­less have worked much bet­ter in the wet than the Yoko­hama rub­ber with which the RD was gen­er­ally fit­ted when new. The orig­i­nal brakes were rated poor in the wet, too. This bike’s mod­ern pads would doubt­less have helped, but even in the dry its front brake was lack­ing in bite. Cu­ri­ously, Yamaha had changed to a sin­gle-pis­ton cal­liper from the ear­lier RD’s twin-pis­ton de­sign. Even the faster RD400E had only a sin­gle disc, though, and most rid­ers were prob­a­bly happy enough.

Most RD250E own­ers were pleased with the air-cooled twin’s per­for­mance and re­li­a­bil­ity, too, and with its gen­eral level of qual­ity. By this time the neat and sim­ple in­stru­ment con­sole in­cluded a light for low two-stroke oil. In­di­ca­tors were self-can­celling, a fea­ture sadly lack­ing in most mod­ern bikes. Iron­i­cally, this RD’s self-can­cellers didn’t can­cel, the bike’s only real fault. In­ter­est­ingly, it had been wired up so the kill-switch was off when in its on po­si­tion, and vice-versa: a neat move in­tended to trick an op­por­tunist thief.

The RD250E was much in de­mand by bike thieves and many oth­ers in its hey­day, but tight­en­ing emis­sion leg­is­la­tion and the de­mand for more per­for­mance meant that its pe­riod of glory was brief. This bike’s re­place­ment, the liq­uid-cooled RD250LC, ar­rived in 1981 with more power and so­phis­ti­ca­tion, but lack­ing a lit­tle of its pre­de­ces­sor’s raw charm. As Yamaha’s fi­nal model in a line of air-cooled 250-cc twins stretch­ing right back to the 1950s, the RD250E was a mighty good way to end the very dis­tin­guished line.

Sin­gle-pis­ton caliper and a solid steel disk at both ends re­quired some se­ri­ous pres­sure to pro­vide any real stop­ping power

Rear sus­pen­sion com­prises twin shock­ab­sorbers with preload ad­justa­bil­ity

Twin-pod clocks with tell-tale lights in be­tween were the rage back in the day

Flat seat meant that you had to re­ally hold on un­der hard ac­cel­er­a­tion

Yamaha’s air-cooled twostroke twins are leg­endary

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