WORDS: PATRICK BODDEN AND MITCH BOEHM PHOTOGRAPHY: … · Mitch Boehm:I see none of the downsides...

May 2006 MOTORCYCLIST 105

MEETING THE

From roach toracer in threeeasy, fun-filleddays. (Ha!) We gobutt-to-saddle atDaytona with themost notoriousand successfulroadracingmotorcycle of the 1970s—Yamaha’s TZ750

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Patrick Bodden: I peer into the back of RussBigley’s dingy gray Chevy van and get a face full

of carbon-fiber two-stroke silencers. “Impressive,” Ithink, “this thing’s the business!” After all, here was aseemingly competent example of one of the most leg-endary racing motorcycles of all time, the bike thatstruck fear deep in the heart of every manufacturerwith large-bore roadracing intentions during the middleand late 1970s. If you had the balls and a decent rac-ing résumé, and wanted a real chance at winning, evenbig-time, world-class winning, well then, mister, it wasa Yamaha TZ750 or nothing.

WORDS: PATRICK BODDEN AND MITCH BOEHM PHOTOGRAPHY: TOM RILES AND CATHERINE BRENNAN

MONSTER

106 WWW.MOTORCYCLISTONLINE.COM May 2006

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and-white two-stroke racebikethat shrieked past the pits atwhat seemed to me an unbe-lievable rate of speed; had to be130 or 140 mph. And thesound! Ear-splitting was waytoo tame a descriptor. After thesession I walked the pits to seewhat sort of animalisticmachine was capable of suchmind-bending velocity and rack-et, and found it cooling menac-ingly in the pit of Midwest racerRobert Wakefield. I approachedthe bike from behind and sawsmoke curling slowly from theskinny stinger exhausts. But itwas the shredded, half-meltedrear slick that lazered itself intomy gray matter. Having neverseen a warm and recently usedroadrace tire up close, the sightfilled me with genuine awe. Iremember thinking, “This thing’sa monster.”

Yamaha quite naturally has

reservations about selling

TZ750s to just anybody with

money and a bag of brave pills.

But AMA rules require 200

copies and you can’t expect

them to simply warehouse the

production left over after Kel

Carruthers takes what he

needs. All the big fours will be

sold, some of them to riders

whose talents were barely equal

to last year’s TZ350. That

thought plainly has the AMA

spooked, because they know

they don’t have 200 Juniors

and Experts who can cope with

what it is feared the Yamaha

will deliver. But there’s nothing

to be done now; Yamaha created

the TZ750 in good faith and

strict conformity with rules

long-standing if not necessarily

wise. — Gordon Jennings,

Cycle, January 1974

Boehm: Yeah, the TZ was abeast, but I still wanted to rideor, better yet, race one, ideallyat a circuit with an equal mea-sure of history. Daytonaseemed perfect, and whenBigley offered up the chance toride Kurt Lentz’s bike (whichBigley took care of for Lentz), Ijumped at the chance.

Bodden: I thought I’d seenthe last of this sort of bike prepback in the ’70s during my daysas an East Coast club racer.Boehm said, “we’d” just have tomake the best of things. Ofcourse, the Heritage Racingguys have managed the impos-sible in impossibly short time somany times over the years thatBoehm has come to expect thisas an entirely reasonableapproach to racebike construc-tion—never mind we’re dealingwith a device, old as it is, capa-ble of 170 mph even in lessthan top-notch condition.

Fact is, racing résumé or not,many a TZ750 fell into less-than-expert hands, meaningthey didn’t have much exquisiteworkmanship lavished on them.No matter. The TZ750, like itssmaller brethren before it, wasso inherently good and so natu-rally cooperative that, as long asthe bike was reasonably wellbolted together and no onewent crazy with ignition timingand carburetor jetting, would golike fury and do so for a longtime. Parts were readily availablefrom local dealers and, as longas they were replaced asYamaha prescribed, didn’t oftenfail. Many a ratty TZ750—MilesBaldwin’s and Richard Chambers’bikes come to mind—wouldallow a motivated and capablesecond-echelon privateer toupstage the more elegant (read:factory) front-runners.

Bigley had had his hands fulltrying to prep two TZs—Lentz’sbike and Bigley’s own Spondon-framed racer—and the prepa-ration he’d done wasn’t meticu-lous. It was the rough-and-ready type that had sufficed allthose years ago during the TZ’sheyday. Problem was, therehadn’t been enough prepara-

You wouldn’t be alone in

wondering if maybe the TZ750

isn’t more than can be man-

aged by mortal man. Plenty of

people are having such

thoughts. Reports in the for-

eign press have told of the

TZ500’s impact in GP racing,

told of the stunned panic with-

in the opposing MV team. Jarno

Saarinen’s death gave MV

another 500cc championship,

but the Yamaha’s early perfor-

mances would seem to give it a

place of pride as the fastest

motorcycle in GP roadracing

history. What, then, might it be

with more displacement, with

virtually a pair of the engines

that made Yamaha’s TZ350 so

formidable during 1973? The

whole concept is intimidating

enough to have given everyone

pause. — Gordon Jennings,Cycle, January 1974

Bodden: The TZ750 forgeda well-deserved reputation asan unbeatable and unstoppableracer. But I’d been blinded bythis bike’s array of shiny newsilencers. Unloaded in the dis-mal, soggy environment of ourDaytona pit, the TZ looks tiredand shopworn, and inspires lit-tle confidence. Boehm and Istand there gazing at it, notsaying much for fear we’ll cometo our senses and go off insearch of margaritas (for him)and root beer (for me). I breakthe silence first: “Well, Mitchie,we’ve not only got a vintageracer, but vintage workmanshipto go with it!”

Mitch Boehm: I see none ofthe downsides at first. What Isee is a real-deal TZ750, and a late-model monoshocker atthat. I’d been in awe ofYamaha’s big TZ since the summer of ’76 at Michigan’sGrattan Raceway. I’d gone thereto check out a real roadracewith Dale Dahlke, anRD350/TZ250 mechanic whowas tuning my XR75 andYZ100 motocrossers while run-ning a small bike shop near mynorthern Ohio home. In an earlypractice session my 14-year-old senses were electro-shocked by a particular red-

“basically ready to go” when itarrived in Daytona. He’dspooned a fresh set of stickyAvon vintage tires onto thebike’s old sand-cast mags, andalthough heavy snowfall in NewJersey kept him from bumpingthe bike off and making sure itran, he told me not to worry.

tion. The Lentz machine is along way from somethingBoehm or anyone else wouldconsider an acceptable risk onthe racetrack. There’s a lot ofwork to do, some evident andsome yet to be discovered.

This hadn’t been part of thebargain when Boehm presentedme with his latest Daytonascheme a few months earlier. Itwas supposed to have beenHeritage Relaxed Racing thistime; just show up, look thebike over, check the tires andspark plugs, and let’s have a goat it. But here it was, take it orleave it. Might as well get onwith it, I thought.

Boehm: My plan going in,which I communicated ad nau-seum in the lead-up to BikeWeek, was simpler—and there-fore potentially less angst-gen-erating—than many of our pre-vious vintage-racing adven-tures. Bigley had told me overthe winter the TZ would be

Because AHRMA didn’t have aclass for what’s arguably one ofthe most historic racingmotorcycles in the world (high-ly ironic, considering it’s theAmerican Historic RacingMotorcycle Association), Iplanned to run the TZ in theChampionship Cup Series’

Formula 40 event, whichallowed any racebike but waslimited to riders aged 40 andolder.

Bodden: When you’re introuble you turn to your friends.And if there aren’t enough ofthem, you draft innocentbystanders. Heritage Racingpartner R.L. Brooks is a long-time friend who’s helped methrough more than oneMotorcyclist vintage-racingadventure. He and I make newfriends on the spot—PhilDiGiandomenico (whom we’dmet briefly a few years before,and father of Jimmy andTommy) and congenial butunsuspecting TZ750 racer (andBrit) Mark Middleton, to namejust two.

We size up the situation fromclues provided by Bigley andour own sleuthing and chart acourse of action. Someonedetects excess fork oil on thetubes right away, so Boehm is

IF YOU HADTHE BALLS AND

A DECENT RACING

RÉSUMÉ, ANDWANTED A

REAL CHANCEAT WINNING,

EVEN BIG-TIME,WORLD-CLASS

WINNING, WELLTHEN, MISTER,

IT WAS AYAMAHA

TZ750 ORNOTHING.

May 2006 MOTORCYCLIST 107

Kurt Lentz’s TZ750 as it appeared in 1984, his final year atDaytona and the year following his outstanding sixth-place fin-ish—and first privateer—in the 200-miler. “The only bikes infront of me were factory Hondas and Yamahas,” Lentz told us.

This is how we spent the three daysleading up to my race—sitting, bending over

and lying down, working all the time. At least ithad stopped raining. Right: Checking out the TZ’s

ergonomics early on. “Uh, can we raise these bars afew inches?”

Lentz’s TZ again, many years—and many parts—later. We’d put30-plus hours of preparation into this thing by the time we shotit out on the Daytona infield, and it showed. Ariel and Jenny areLentz’s daughters, by the way.

it isn’t a garden-variety piece—it’s of an exotic threadpitch/diameter, and much run-ning around reveals that areplacement isn’t to be found inall of Daytona. Back atDiGiandomenico’s homemachine shop, a different-stylebolt has its head turned on thelathe and a slot sawed into it tosubstitute for a hex. We’re backin business. A one-hour jobtakes two capable andresourceful technicians anentire day.

Meanwhile, I’m workingthrough my own misery.Carburetor synchronization, inparticular, seems either inter-minable or impossible, I can’tdecide which. This thing might

be a legendary motorcycle, butits carburetor linkage—fourindividual cables from throttleto carburetors—is becoming alegendary pain in the ass. Getthree just right and I run out ofadjustment on the fourth. Getfour more or less OK and, if Imove the cables a bit rein-stalling the fuel tank, the carbsgo out of sync again. Finally,when everything seems reason-able, I discover a crack in thetop half of the throttle assem-bly. Bless his heart, old Bigley(working feverishly on his ownTZ) just keeps the parts comingand offers up a replacement forthe cracked piece. The new partinstalled, I check carb sync forthe thousandth time and pro-

nounce it fine.As the day rolls by I keep

finding things to do or fix.Racebikes are like infinitesponges of time and resources.All done (or so I think), I stepback, admire how simple it alllooks, and wonder how prepa-ration—and replacing a fewparts—could possibly take solong. Of course, there are otherconcerns, such as, would thebike be safe for Boehm to ride?At this point I’m not sure.

Boehm: By this point I’mhorribly frustrated. We’dplanned to run the bike intoday’s informal Team Hammerpractice so I could get accus-tomed to it and the revised,much-tighter Daytona circuit.

wise to at least one problem.No big deal. Bigley has newseals, so R.L. and Phil D. getbusy replacing them. As is sooften the case with seeminglyminor problems, unforeseensnags ground our resolution toa halt. The guys aren’t anysooner into the job than they’restalled by the Allen bolt holdingone of the fork legs together;its internal hex is no longerhexagonal and the bolt isn’tresponding to wrenches orcusswords. It’s off to localeswith better weapons—DiGiandomenico’s nearbyDaytona garage—whereextracting the bolt proves fairlyeasy, even if it means destroy-ing it in the process. Of course,

corrosion. Bigley announcesthat seals for these things areextinct. Now what? I notice 5/8cast into the cylinder body andopine that an American orBritish seal might work, espe-cially since it looks ordinary inevery respect. Another tour ofDaytona parts purveyors pro-duces two likely candidates—aseal kit from an auto partsstore for Lord knows what, andanother for some Harley. I optfor the Harley part, and itworks. Close enough.

Photographer Tom Riles issympathetic to our plight, andalthough he seems to believe allthis commotion is futile, herecords it. He also holds themaster cylinder while I honelegendary corrosion out of it.

We reassemble everything andin short order have a function-ing brake. Trouble is, the pedalnow contacts one of theexhaust pipes. We run out ofadjustment rod trying to fix it,and once again a modified gar-den-variety bolt is substitutedfor an OEM part and we’re inbusiness.

We munch Boehm’s worker-compensation food—burgers,Milky Ways, sodas andGatorade, but no blue drinks—and survey our progress. Wenow have a functioning, non-leaking fork, proper throttleaction and working front andrear brakes. Paul Thede of RaceTech makes the TZ’s yard-longsingle shock/spring unit work

as well as he can with limitedtools. Everything seems rea-sonably bolted together. Wehave water in the radiator, oilin the gearbox and premix inthe tank. Do we have spark?We have faith.

Time to start the beast. Aftera spirited push the TZ comesto life in a grand spasm ofsound and smoke. The smokeclears, and so does the exhaustnote. I let it rip up the pit road.By God, it feels good andsounds fierce! I turn aroundand let it rip again. I’m thrilled,and so are the guys. The trackGestapo is less so. I can’t hearhim even at the evil PA sys-tem’s 120dB volume, but he’sissuing threats of eviction if Idon’t cease and desist. I hear

of the threats back in our pit,but I don’t care. We’re nothurting anybody. Maybe scar-ing a few people, but we’re notendangering anyone.

The bike is beginning to lookpretty good; Riles even calls itphotogenic. It’s scuffed andmore than a little shopworn,but it’s getting cleaner by thehour. Our second Daytona dayis over and it’s back to theLagoon for more Mexican foodand blue drinks.

Boehm: When the TZ lit off Iwas jacked! It sounded so cool,so crisp, just like the 500cc GPbikes I’d seen and heard atLaguna back in the day. I knewit’d be a rocket, and couldn’twait to ride it. After all themyths that’d circulated about

the big TZ, I’d finally get to seewhat the monster was reallylike. Problem was, we’d onceagain run out of time for prac-tice, and tomorrow was theFormula 40 race. I was highlypissed—which meant moremargaritas that evening todrown my sorrows.

Bodden: Day three is raceday, and we go backward. Thefront brake decides to quitworking. We bleed it, and itcomes back to life, but it isn’tideal. The crew knows we’rerunning short of time andworks with Boehm on controlpositioning, all the time cleaningthis and that, checking fasten-ers, installing breather hosesand catch bottles, etc. Then

Not a chance. And the waythings are going, getting anypractice the following day looksiffy at best. Not a good start.

Bodden: A Daytona day hascome and gone. Boehmannounces quitting time (withhelp—via threats—from theear-bleed PA system) and herdsthe crew to the local Mexicaneatery, the Cancun Lagoon. Averitable food fiesta ensues, thefirst of three consecutive suchsorties. The fare is acceptable,as are the margaritas (so Ihear), some of them doctoredwith what looks like blue toiletbowl freshener. The moreeveryone drinks, the bettereveryone pronounces the food.By evening’s end we could havesubstituted linoleum for taco

shells and Boehm & Co. wouldhave pronounced them mucho

splendido.The next day is a repeat of

the first, but this time the rearmaster cylinder is the DaytonaGremlin of the Day. Accordingto Bigley, all it needs is a goodbleeding. Boehm says bleedingis unnecessary, as he “never”uses the rear brake. (Funny howhe manages to return everyracebike I build for him with aseriously blued rear disc. Maybenot Cancun Lagoon blue, butblue just the same.) R.L. and Irun fresh fluid through that leg-endary magnesium TZ750 mas-ter cylinder and can’t get anypedal. We remove it only to finda punctured seal and big-time

May 2006 MOTORCYCLIST 109108 WWW.MOTORCYCLISTONLINE.COM May 2006

THE TZ COMESTO LIFE IN A

GRAND SPASMOF SOUND AND

SMOKE. THESMOKE CLEARS,

AS DOES THEEXHAUST NOTE.

I LET IT RIP UPPIT ROAD. BYGOD, IT FEELS

GOOD ANDSOUNDS

FIERCE! I’MTHRILLED.

>CLASSIC FILE

Long-suffering Bodden, hard at work just hours before we lit theTZ750’s fire for the very first time. Right: Push-starting thebeast and hearing its crisp, high-pitched wail bounce off the

grandstands and our pit tent was almost a religious experienceafter three straight days of intense toil and angst.


frantic back and forth, practiceand the Formula 40 race havecome and gone. Like all of us,Boehm is not a happy man, andit shows.

Boehm: At this point I was ina foul mood. We’d missed everylap of practice along with myscheduled race. Luckily, CCShead honcho Kevin Elliott, whoI’d been hounding every hour forwhat seemed like days, gave methe go-ahead to take part in ashort practice the followingmorning (Sunday) and aSuperbike-spec race later thatafternoon with highly modifiedmodern bikes. My goal of actu-ally riding a legendary YamahaTZ750 in anger wasn’t dead yet.

Even so, I worried plenty thatevening at dinner, our third in arow at the now-infamousLagoon. The TZ’s front and rear

there’s some business with twoof the plug wires. The bikestarts, but reluctantly, and hasa case of what Kevin Camerononce referred to as the piff,paff, poofs. Sometimes two-strokes do this and then clearup. This doesn’t clear up.

Back in the pits it’s decidedthe other two wires also needto be changed. But now thebike won’t start at all. That’sprogress as far as I’m con-cerned and I say so, assertingthe wires needed to be putback as I remember themregardless of what the booksaid. No one listens to me.Middleton appears, doesn’t saya word to anyone, and reposi-tions the wires just as I saidthey should have been in thefirst place. We push again andthe bike starts. During all this

>CLASSIC FILE

Time to grid for the race, which meant big butterflies.Of Kurt Lentz, who raced this bike back in the day,

Cycle World’s Kevin Cameron said, “Lentz was theman in one of ABC’s Agony of Defeat videos, fish-

tailing through the hay bales at Daytona in ’78and crashing heavily. He crashed into the pond at

Loudon in ’76, breaking his neck. He said later,‘There I was, under the water and paralyzed. Ithought, well, they’ll either get me out or they

won’t.’ He was soon riding again. [In1983] he finished sixth at Daytonaand had himself driven around thepits sitting in the side door of his

van to show himself to his peo-ple. He survived many heavy

crashes and seemed to beone of those guys who justgoes faster and faster until

they pile. At least onequite nice wife signed off,saying she didn’t want to

watch a prolonged suicide.He, like Jimmy Adamo and

Kurt Liebmann, was one ofracing’s lifers.”

Sadly, thegrand old circuit that wasDaytona International Speedway was badly neutered in early ’05to keep Superbike tire temperatures—and speeds—down. Thesecond half of the infield is now almost kart-track tight. It’ssafer, but feels exactly like what it is: a Band-Aid fix that doesn’tdo justice to the track’s motorcycling history.


suspension remained way softdespite dialing in max preload(the springs were too soft), anddamping seemed non-existent.Kenny Roberts Sr. told me amonth earlier to get up off theseat on the banking, that thebike was “sure to wobble.”Considering the thing wascapable of 170 mph, this didnot sit well, even with severalblue drinks circulating throughmy system. (Who says alcoholmakes you brave?) There wasmore: I barely fit on the bike.Seat-to-peg distance was ascant 13 inches, way less thaneven the sportiest of sport-bikes, and lifting my feet ontothe pegs while seated was achallenge. My knees hit the fair-

ing sides once I got seated, andI wasn’t sure the cutting we’ddone to the fiberglass would beenough. And what of carb jet-ting? Would it be rich, whichmight have the bike loading upon the start line? Or would itrun lean, and seize solid exitingthe chicane, highsiding me into acement wall at 80 or 90 mph?

And even if all of that stuffturned out to be workable, howdifficult would it be to ridequickly? Stock TZs—at leastthe early twin-shock versions—made around 90 horsepower.But Bigley had told me Lentz’sbike sported radically portedcylinders, Lectron carburetors,new-generation reed valves andmodern expansion chambers,the end result being somewherebetween 120 and 130 rear-

wheel horsepower. That doesn’tsound like much relative totoday’s 150-horse open-classers. But when you’re talk-ing about a 346-poundmachine with famously abruptpower, mean-Alice handling,soft, damping-less suspension,skinny tires and a reputationfor extreme wobbles at speed,all on a racetrack I’d not yet

ridden, I was beginning toquestion the entire scheme.

Sunday dawns clear andbright, and the crew arrivesearly to check the bike in antici-pation of the precious fewpractice laps I’d been granted.We get the bike through techinspection (raised eyebrowsgalore) and warm it up along pit

row, which attracts a crowd. AsBodden blips the TZ’s throttle,rapid-fire smoke bursts andtwo-stroke Brrraaaam! soundsfill the air, and I have the feelingghosts are stirring throughoutthe Speedway’s towers andgarages. It’d been many yearssince that unique four-cylin-der/two-stroke sound had rico-cheted off these legendarygrandstands. Speedwayannouncer Richard Chambers,who’d ridden TZ750s to someexceptional finishes back in theday (and who still has his TZracer), rides by on his scooterwith a knowing smile on hisface. He tells several old-schooltales over the PA system aboutKurt Lentz and his TZ, which I’m

about to ride. A hard shove gets the

Yamaha rolling. You work it up

to a trot, then hop on sidesad-

dle and bang in the clutch to

spin the engine, which responds

with a few raspy barks before

settling into a sullen staccato

as you head for the course. At

first you go gently, waiting for

the water-temp needle to lift

off its peg, teasing yourself

with short bursts of speed. One

full lap, then another half-

throttle tour of the infield

before you let yourself fall into

the familiar racing patterns,

pulling the bike upright and

rolling on throttle as the last

yards of the final infield turn

flicker past.

— Gordon Jennings, Cycle,January 1974

Relatively speaking, theTZ750 is a tiny motorcycle,

more like a current 250 than anopen-classer. I’m reminded ofthis as I roll down pit lane forthe first time and enter thetrack just before Turn 2—theInternational Horseshoe. Thecramped seat-to-peg layoutmakes it really hard to move mybody around on the bikethrough the much-tighter infield,and by the time I accelerateonto the back straightaway aquarter-mile before the chicane,my calves, quads and lower backare already cramping.

With that the busy, four-

cylinder snarl becomes a hard,

hammering shriek and the

Yamaha hurls itself at the high

south banking, its front wheel

almost too light to steer.

Quicker than memory it claws

its way around and flashes out

along the back straightaway,

tach needle surging next to the

red pie-slice as your toe twitches

at the shift lever. All the sensa-

tions are familiar but of a mag-

nitude that reaches past the

limits of experience. Speed

blurs everything but a narrow

tunnel ahead. Wind buffets and

plucks at your leathers, and a

rash of heat from the radiator

sears your face. — GordonJennings, Cycle, January 1974

The TZ feels incredibly lightand whippy despite the narrow(and low-mount) clip-ons, whichoffer little leverage. The bikeseems to respond to weighttransfer as much as bar pres-

AHRMA DIDN’THAVE A CLASS

FOR ONE OFTHE WORLD’S

MOST HISTORICRACING

MOTORCYCLES,IRONIC

CONSIDERINGIT’S THE

AMERICANHISTORICRACING

MOTORCYCLEASSOCIATION.

>CLASSIC FILE


sure entering corners, and I findI can get fairly aggressive with itearly on. Midrange power is sur-prising, but I’m taking it easy atfirst; Bigley told me the enginewas fairly fresh and probablyneeded a few laps to get up to

temperature before I flogged it.Both ends feel way soft, but it’snot a problem at the speeds I’mrunning. The brakes are posi-tively wooden, but I’m used tothat. Luckily, the Avon tireswarm and scuff quickly, andkeep me from worrying aboutgrip—unless the back tire sud-denly gets oiled up, that is.

You clamp your knees

against the tank more tightly

and sneak a finger forward to

tug at the brake lever, just

checking. You never did that

before, but you do it now.

Moments later you’re braking

for the chicane, downshifting,

hauling at the handlebars and

feeling the tires shudder. Then

you’re driving hard into the

north banking, hunching for-

ward to keep the front wheel

from lofting, waiting until you

have it aimed before using all

the power, bracing yourself for

the bike’s awesome, catapult-

ing acceleration. And forming

in your mind is the nagging

thought that while sure as hell

somebody has done the right

thing, somebody at Yamaha,

what they’ve done just might

not be the right thing for you.

— Gordon Jennings, Cycle,January 1974

By lap five I’m starting to get

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I’d always wanted to see what riding the bike thatwon the Daytona 200 eight years running would belike—and I’d finally gotten the chance courtesy of

Russ Bigley, Kurt Lentz and a host of friends.After my eight-lap race, Team Yamaha’s

Jamie Hacking and Jason DiSalvo cameover to check out the bike. Hacking

made jokes about the TZ’sskinny fork tubes, while

DiSalvo jumped aboardto discover he fit the

bike perfectly. All ofwhich made me

understand whythe thing hurt

me so badly.

Continued on page 168

116 WWW.MOTORCYCLISTONLINE.COM May 2006

COCKPITThose spindly fork tubeswere part of the reason KelCarruthers said, “Everythingwas too flimsy. The first timewe tested [in the U.S.] we hadRoberts, [Gene] Romero and[Don] Castro riding. I can’tremember Kenny’s lap times,but Castro and Romero werelike 8 seconds slower. Theycouldn’t ride the bike. Itscared them because itwouldn’t handle like theywanted it to.”

WHEELS/BRAKESWhile 1977-/’78-spec mono-shock TZs came with betterbrakes than the street-spechardware found on early twin-shock TZs, most privateersupgraded to better items.Lentz’s bike ended up withSpondon bits, and though goodenough for the late ’70s, theyfelt plenty wooden in 2005.Magnesium Morris wheels arelight, but when old and brittle(like these) are prone to disin-tegration. Nice.

ENGINEA stock D-model TZ750made 120 horsepower at thecrank—about 100 at the rearwheel—via 66.4 x 54mmbore and stroke (747cc) and34mm Mikunis feeding reedvalves. Lentz’s TZ makesapproximately 25 morehorsepower via 38mmLectron carbs, radical cylin-der porting and specialSwarbrick exhausts. At justover 300 pounds it was ahandful to ride quickly.

REAR WHEEL/SWINGARMThe Lentz TZ’s swingarm isan ugly-but-functionalVesco unit. Many twin-shock TZs were retrofittedwith monoshock kits afterRoberts showed up with theOW31 in ’75; productionversions didn’t appear untilthe D-model bikes in ’77.We ran Avon’s race-com-pound AM22/23 tires, a110/80-18 front and a150/80-18 rear. They’resuperb.

YamahaTZ750Hard Parts

>CLASSIC TECH

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Relatively unchanged for years, yet hugely competitive


Hellacious Hybrid >CLASSIC FILE

Russ Bigley isn’t just one of America’s most out-of-controlTZ750 enthusiasts. He’s also a capable racer who likes his

Tee Zeds to be as fast and functional as they are legendary. All of which explains his personal TZ750 racebike, which is, shall

we say, vastly different than a standard TZ such as the one I rode.His bike is anchored by an ’83-spec Spondon aluminum frame, one ofonly a handful produced by the British chassis specialist. Ed Johnsonmachine-work and Yoyodyne titanium fasteners are sprinkledthroughout, while an Öhlins shock and CBR900RR fork keep thingssteady. Marvic wheels mount Michelin radials, Air Tech bodyworkprovides streamlining and Brembo brakes slow everything down.

And that’s quite a job considering the bike weighs 308 poundsand makes 144 rear-wheel horsepower thanks in part to customSwarbrick pipes, 41mm Lectron carbs, seven-port YZR500 cylin-ders and heads and loads of cylinder porting.

Bigley and British co-rider Mark Middleton (who runs his owntrick TZ in the U.K.) rode the hybrid in CCS’s 200-mile Team

Challenge event at Daytona. And though a stuck carb needletook them out at the race’s halfway point, the duo ran

surprisingly quick laps and raisedplenty of eyebrows along

pit wall. It’s somethingBigley’s become

quite good at.

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Left: MarkMiddleton atspeed aboardthe hellacioushybrid atDaytona. Bigley(in T-shirt at farleft) plans torun his TZ at

this summer’s 2-Stroke Extravaganza at BeaveRun Racewayon the weekend of July 1–2. And if all goes well there, he andMike Himmelsbach plan to try to knock off the superbikes atthis year’s Willow Springs 200 in the fall. Their plan? A 7-gallon fuel tank and low tire wear, which would keep them tojust one pit stop.

Russ Bigley’s TZ750 is not like theother ones …


Giant-Killer to Giant >CLASSIC FILE

If you were evenremotely interested in

roadracing back in 1973,you—along with fellowenthusiasts, bike journalistsand factory engineerseverywhere—wereawestruck when Yamahaannounced it would field afour-cylinder two-stroke

750-class roadracer. You were awestruck—or

shaken to your core if youwere a competing manu-facturer—because Yamahawas already dominatingroadraces all over theworld with its small-but-

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fierce 350cc twins. These giant-killers, as they had come to beknown, won regional, nationaland international races againstmachines with twice the dis-placement from the likes ofHonda, Kawasaki, Suzuki,Triumph/BSA and Harley-Davidson. In fact, these TR350shad won the past two Daytona200-milers, and in 1973 thenew water-cooled TZ350 won atDaytona with Flying Finn JarnoSaarinen, Kel Carruthers and JimEvans going 1-2-3. So theannouncement of a 750cc ver-sion was a shocker.

A few months after his runner-

up finish, ex-250 world champ(and Yamaha U.S. team manager)Carruthers traveled to Japan totest the TZ750 prototype. Hesuggested some changes, mostof which were carried out on thespot, then returned to the Statesto heighten excitement—or fear,depending where you stood—byannouncing that Yamaha’s newracer was capable of 182 mph.

To be fair (and historicallyaccurate), Yamaha wasn’t thefirst to construct 750cc two-stroke roadracers. Suzuki andKawasaki had already done so inthe form of their street-basedthree-cylinder machines, as man-

A brief history of the Yamaha TZ750

dated by AMA rules in America,as well as those of the BritishACU that had gotten Formula750 international racing off to apromising start in Europe.There’s no question thesemachines were exceptionallyfast, the water-cooled SuzukiTR750 having been the firstmachine toexceed

175 mph at Daytona in ’72.Kawasaki’s H2R—and, later, thewater-cooled KR750—werecertainly in the same league.

But those bikes shreddedtires, weren’t especially cooper-ative handlers, and showeduneven reliability. Never mindthe four-strokes; they had theirown brands of misery. Two-strokes were the coming thing,and one only had to look acrossthe Atlantic to the 500ccGrands Prix to see that.

Yamaha upped the ante con-siderably with the TZ750. It lit-erally took the wealth of expe-

rience and engineering know-how accumulated from

GPs of the ’73 season. Like the500, the TZ750 utilized reedvalves to balance tractabilityagainst sheer horsepower. Andin the handling department, theTZ750 would eventually acquirethe monoshock rear suspensionof the 500. The TZ750 wasmuch more a big GP machine—a purebred racer—than it wasan extrapolation of the smallerYamaha production racers.

What’s not clear is howYamaha got away with this bit ofGP subterfuge. Essentially,Yamaha invaded racing—bothAMA and Formula 750—thatwas presumed to be based, atleast in the area of engines and

frames, on street-going mass-pro-duced models and readily availableaftermarket accessories. It wasfurther presumed this format gavea greater number of factories achance at racing success with thebig machines that had capturedthe public’s imagination by theearly ’70s. And it gave racingspectators a greater number ofmachines with which they couldconnect on a personal level.Yamaha had toyed with the ideaof a street version of the TZ750,one example of which was shownat the Tokyo show of 1971, but itwas put away afterward, never tobe seen again.

Perhaps it’s simple—a brilliant

years in GPs, as well as from thebusiness of producing over-the-counter racing machinery, andmultiplied it. Much is made of theidea the TZ750 was createdfrom doubling the engine of thepotent TZ350—just widen thecrankcases and plug in an extracrank assembly, cylinder blockand cylinder head, so to speak.As logical, simple and expedientas this solution appears, it fallsfar short in defining the genesisof the TZ750. The TZ750 owesas much, if not more, to its onlysmaller sibling, the YamahaOW19 500 Grand Prix racer, amachine on which Saarinen (afterDaytona) had won the first two

Before he joined Team Honda, Freddie Spencerwas a TZ750-mounted terror. Riding an ErvKanemoto-built monoshocker for HowardRacing, Spencer nearly won the 1980 Daytona200 at the age of 18. A burned crank bearingcaused by the ingestion of sand when theweather turned ugly took him out of the racewith only 10 laps remaining. He’d have beenthe youngest-ever winner of the 200. Of theTZ, Spencer says this: “Some people werescared of them. They were fast, especiallyErv’s bikes, but they had pretty mellow power-bands; they weren’t nearly as peaky as the250s I rode. I always felt really comfortable onthem.” That Easter, Spencer garnered his firstinternational fame when he beat KennyRoberts and Barry Sheene at Brands Hatch atthat year’s Match Races. The rest, as they say,is history.


>CLASSIC FILE

FROM ITS INTRO-DUCTION TOAMERICA AT

DAYTONA IN ’74AND A WIN BY GP

HERO GIACOMOAGOSTINI TO ITS

LAST 200 WIN IN’82 BY KIWI

GRAEMECROSBY, THETZ750 WON

EVERYDAYTONA

200.

idea being hard, if not impossi-ble, to suppress. The TZ750proved as unstoppable politicallyand emotionally with both raceorganizers and the public as itwas unstoppable by any racerriding anything else. The bikewas simply not to be denied onany basis. And Yamaha, oneway or another, took fulladvantage of the fact that infi-nitely more people wanted tosee its latest creation on thetrack than would have pre-ferred to see it go away.

Yamaha returned the favor.Its big, spectacular GP-bredmachine transformed AMA andFormula 750 racing into big,spectacular affairs that farexceeded other makers’ entries.In short order, the Ducatis,Nortons, Triumphs, MotoGuzzis and even Hondas fadedfrom the scene, forever relegat-ed to that bit of motorcycleracing history that predates theYamaha TZ750.

To say the big TZ dominatedis to state the obvious. From itsintroduction to America at

Daytona in ’74 and a win byGP hero Giacomo Agostini toits last 200 win in ’82 by KiwiGraeme Crosby, the TZ750won every Daytona 200. Fromits first year in Formula 750 in’74 propelling John Dodds tothe championship to its last in’79 carrying Frenchman PatrickPons, the TZ750 won everychampionship and practicallyevery race. Epic battles werefought, reputations wereforged and champions weremade. In particular, CanadianSteve Baker became America’sfirst world roadracing champi-on by riding a nearly flawlessseason in ’77 on his way tothe Formula 750 crown.

The TZ750 accomplished allthis with surprisingly fewchanges. In the six years ofproduction, from the ’74TZ750A to the ’79 TZ750F,there were really only twochanges. Partway through theB model-year engine displace-ment grew from 700cc to750cc by enlarging the borefrom 64.0mm to 66.4mm. And

with the advent of the D modelin ’77, the TZ750 finallyacquired Yamaha’s trademarkmonoshock rear suspension.Also gone in ’77 were the fourflat-sided, failure-prone expan-sion chambers, replaced byproper conical-shapedexhausts, three positionedunder the engine and the fourthsnaking its way upward, acrossand through the frame, exitingrearward just below the seat.

Through the years, engineoutput increased from 90 to120 horsepower and beyond,often through the efforts ofenterprising privateers. All thewhile, the Yamaha retained areputation for reliability as wellas blinding speed, so much sothat a few examples foundtheir way into 24-hourendurance racing, their successcut short primarily by theirundeniable thirst. Yamaha builtonly about 500 of these fabu-lous roadracing machines, andthere were a substantial num-ber of specials built aroundTZ750 engines.

For those of us who remem-ber the TZ750 well, the bikeremains contemporary. Its lookshaven’t faded with age. Park anice example—even one with alittle race wear—anywhere andthe bike can still stop onlookersin their tracks. People remem-ber. There are those who wishto make the history of this fab-ulous racing machine comealive, who believe that the bigYamaha should be preserved inits proper environment, which isto say restored and ridden athigh rates of speed in front ofthose who remember it andthose who will now be just asamazed as we all were in 1973.How many TZ750s must therebe out there waiting for such anopportunity?

Those who’d like to see and

hear the legendary TZ750 in

action can do so over the week-

end of July 1–2 at BeaveRun

Raceway in western

Pennsylvania. Click on

www.usgpru.com for more

information. MC


into the groove despite mycramping legs. The thing is fast.But then I notice the tempera-ture gauge as I head for the tri-oval; it’s gone past 90 degreesCentigrade and is heading for100, which Bigley called thedanger zone. I imagine beingflicked off into Turn 1 as theengine seizes, so I back off androll into the pits a lap later,thinking unhappily that thesemight be my only laps till myrace later in the day.

The crew goes over the bikewhile I head for the CCS officeto double-check my race time.Two hours later we’re pushingthe bike to start/finish and thebutterflies are swarming. Notbecause I’m worried aboutbeing competitive (I’m griddedlast, and in a class filled withlate-model R1s, GSX-Rs andZX-10s!), but because I wantthe bike to last, want to make itback in one piece, want tobump right up against thisthing’s ragged edge and seewhat’s there. Dunlop’s race-tireguru Jim Allen walks by andgives me a thumb’s up, butwonders privately about thebike’s magnesium wheels, whichare known to become brittlewith age and dis-integrate atspeed. He keepshis concerns tohimself, which isprobably a goodthing.

I take it easy atthe start and usethe first lap to getre-acquaintedwith the bike. Mygoal is simple: Runthe thing as hardas I can, andhopefully catch afew backmarkersso the race feelslike somethingmore than a prac-tice session. TheTZ feels reason-ably good enter-ing the chicane onlap one so I carryextra speedthrough the exit

and hammer the throttle. Thebike shakes its head underpower but remains true, andI’ve got myself a decent drive. Ican hear the TZ’s raspyexhaust note bouncing off thewall of the banking, and itsounds great. Time to see howfast this thing is. Ripping offthe east banking a quarter ofa mile later headed forstart/finish, the bike bottomsforcefully on the roller bump atthe banking’s exit and goesinto another speed wobble atwhat must be a buck-fifty.Roberts wasn’t kidding.

The shimmy’s not badenough to cause me to backoff, and I carry Big Speed paststart/finish. But I blow theentrance to Turn 1, arguablythe toughest bend in all ofmotor racing. Through theHorseshoe and the rest of theneutered infield I’m having ahell of a time getting any sortof rhythm going; the brakesare weak, the bike has littleengine braking on decelera-tion, and though I’m riding alot faster now than I had inpractice, I’m lurching all overthe place—and surely lookinglike an idiot on an old bike

floundering at the back of thepack in the process.

The bike wants to wheeliethrough the gears exiting theinfield onto the back straight,but I’m more worried aboutthe oily mist that seems to berising from around my crotch. Isneak a look down at my rightthigh and knee and find theleather there shiny with petro-chemicals. It’s just the gas/oilmixture backwash through thecarbs and intake system typi-cal of most two-stroke race-bikes, but I don’t know that—and images of oil-coated reartires begin playing on theinsides of my eyelids. Pitchingthe bike into the chicane fiveseconds later at 90 or 100mph takes mammoth faith, butthere’s no slide. Guess it’s OK.

I try to get ready for thehigh-velocity shake/shimmythat’s coming through the eastbanking’s G-out, but my atten-tion is focused on an almostunreal level of vibration andnoise permeating the cockpit.It’s way worse than I remem-ber, so I naturally think some-thing’s gone terribly wrong.What’s happening is that I’mriding the bike a lot fasternow, and it’s doing what big,nasty two-stroke racebikes doat speed. But again, I don’tknow this, all of which keepsme from nailing Turn 1 again.The temperature gauge againflirts with the 100-degree Cmark, but I ignore it. Bigleysaid to.

By this time both my feetare asleep and buzzing withpins and needles due toreduced blood flow caused bymy pretzeled legs, but there’stoo much craziness happeningto think about them now. I geta bit overzealous exiting theHorseshoe, lose the back endin a lurid slide and almost runoff the track after I get thingsbuttoned up. The bike rocketstoward the tight section of theinfield and I nearly overshootthe right-hander due to myright hand cramping fromgrabbing the brake lever sohard for so long. I tell myself

MEETING THE MONSTERContinued from page 115

KENNYROBERTS HAD

TOLD ME TOGET UP OFF

THE SEAT ONTHE BANKING,

THAT THE BIKEWAS “SURE TO

WOBBLE.”CONSIDERING IT

WAS CAPABLEOF 170 MPH,THIS DID NOT

SIT WELL, EVENWITH SEVERAL

BLUE DRINKSCIRCULATING

THROUGH MYSYSTEM. (WHOSAYS ALCOHOL

MAKES YOUBRAVE?)

A big obstacle to fast laps was theTZ’s way-soft suspension, which letthe bike run wide exiting cornersand limited my drive offthem. Still, rippingaround that leg-endary circuiton thatshriekingmotorcy-cle was ahugethrill.


to relax, but my rapid-firebreathing fogs my shield and Imiss my turn-in point two cor-ners later. I can see folks in thegrandstand as I rattle by, and Ijust know they’re laughing theirasses off.

I realize I’m tired and ridingout of control—and then I getthe crossed flags that signal therace’s halfway point. Still fourlaps to go? Damn! It’s not somuch the power that’s makingthe TZ hard to ride; power hitshard at 7000 rpm and redlinesat 11,000, so there’s a decentspread there. The problem, forme at least, is that the engine isso much better than the chas-sis. The soft suspension, weakbrakes and racklike ergos aretaking their toll, making me ridespasmodically, unable to besmooth. Somehow I manage torelax a bit ripping along thebanking, and I wonder brieflyhow riders—especially thoselarger than average—rode

these things at race speeds for200 miles here. Amazing.

In the race’s latter stages Imanage to put together a cou-ple of decent laps, and evencatch a few slower riders—although Team Yamaha’sJason DiSalvo and JamieHacking lap me toward theend while testing for the AMAraces the following weekend.At the checkered flag I pull inand collapse onto the TZ’stank as I roll to a stop whereBodden is standing. Hackingand DiSalvo come over tocheck out the bike, as does JimAllen, who then tells me of hisconcerns about the magwheels. Someone says theygot me at 168 mph on radar,which makes me extra happythe wheels stayed together.Hacking breaks us all up withhis quip, “My mountain bike’sgot thicker fork tubes thanthat thing!” DiSalvo throws aleg over the TZ’s saddle and

fits perfectly; he says he’d liketo try riding it sometime. Allen,who rode his share of racelaps on big TZs, laughs at thethought. But we all knowDiSalvo would be crazy-fast onthe thing.

Bodden: I’m relieved after-ward, just as I’d been 10 yearsearlier when I’d watchedBoehm race the Drixton Honda500 I’d prepared (the very rea-son we were having this 10-year commemoration atDaytona). I was afraid theremight be some problem I didn’tknow about—and didn’t havetime to find—lurking deepwithin the TZ. I felt a greatsense of privilege being able towork on one of the most leg-endary racing motorcycles ofall time. The few moments Iwasn’t preoccupied during thatlong weekend, my head wasfilled with images of Agostini,Roberts, Johnny Ceccoto,Steve Baker, and, as a compa-

triot, of Patrick Pons and hiswin at this very circuit in1980. I also reminisced aboutlocal greats, some champions,some not—Chambers, RichSchlachter, Greg Smrz, et al. Ireminded myself that, despiteall the apprehension surround-ing the TZ750’s release, anddespite its mind-bogglingacceleration and top speed, itearned an enviable safetyrecord. It may have beenfierce, but it wasn’t vicious.

Boehm: I’m spent, buthugely jazzed about the way itall came off. By riding the TZhard in a real roadrace atDaytona, I’d gotten a firsthandglimpse into a large portion ofAmerican roadracing’s history.Lentz’s TZ wasn’t quite themonster I expected. But theexperience did show me themonstrous skill and determina-tion of the riders who wentfast on them back in the day.Amazing stuff. MC

I TELL MYSELFTO RELAX, BUTMY RAPID-FIRE

BREATHINGFOGS MY

SHIELD AND IMISS MY TURN-

IN POINT TWOCORNERS

LATER. I CANSEE FOLKS INTHE GRAND-STAND AS I

RATTLE BY—AND I JUST

KNOW THEY’RELAUGHING

THEIR ASSESOFF.

MEETING THE MONSTER

Ten years after our first vintage-racing get-together at Daytona, the ’05 version of the Cardiac Kidspose with the Bigley/Lentz TZ750 on Sunday afternoon in Daytona’s infield just hours after ourrace. Left to right: Shannon Silva, Todd Henning, Yours Truly, R.L. Brooks, Patrick Bodden, BillyOrazio, Michael Mutter and Mike Sidinsky. Missing are Russ Bigley, Mark Middleton and PhilDiGiandomenico. My race number—184—came from my motocross racing days.

WORDS: PATRICK BODDEN AND MITCH BOEHM PHOTOGRAPHY: … · Mitch Boehm:I see none of the downsides...

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Transcript of WORDS: PATRICK BODDEN AND MITCH BOEHM PHOTOGRAPHY: … · Mitch Boehm:I see none of the downsides...