Yamaha TZ750: Meeting The Monster

From roach to racer in three easy, fun-filled days. (Ha!) We go butt-to-saddle at Daytona with the most notorious and successful roadracing motorcycle of the 1970s--Yamaha's TZ750

By: Patrick Bodden, Mitch Boehm, Photography by Tom Riles, Catherine Brennan

Sunday dawns clear and bright, and the crew arrives early to check the bike in anticipation of the precious few practice laps I'd been granted. We get the bike through tech inspection (raised eyebrows galore) and warm it up along pit row, which attracts a crowd. As Bodden blips the TZ's throttle, rapid-fire smoke bursts and two-stroke Brrraaaam! sounds fill the air, and I have the feeling ghosts are stirring throughout the Speedway's towers and garages. It'd been many years since that unique four-cylinder/two-stroke sound had ricocheted off these legendary grandstands. Speedway announcer Richard Chambers, who'd ridden TZ750s to some exceptional finishes back in the day (and who still has his TZ racer), rides by on his scooter with a knowing smile on his face. He tells several old-school tales over the PA system about Kurt 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 sidesaddle 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, the TZ750 is a tiny motorcycle, more like a current 250 than an open-classer. I'm reminded of this as I roll down pit lane for the first time and enter the track just before Turn 2--the International Horseshoe. The cramped seat-to-peg layout makes it really hard to move my body around on the bike through the much-tighter infield, and by the time I accelerate onto the back straightaway a quarter-mile before the chicane, my calves, quads and lower back are 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 sensations are familiar but of a magnitude 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." -- Gordon Jennings, Cycle, January 1974

The TZ feels incredibly light and whippy despite the narrow (and low-mount) clip-ons, which offer little leverage. The bike seems to respond to weight transfer as much as bar pressure entering corners, and I find I can get fairly aggressive with it early on. Midrange power is surprising, but I'm taking it easy at first; Bigley told me the engine was fairly fresh and probably needed a few laps to get up to temperature before I flogged it. Both ends feel way soft, but it's not a problem at the speeds I'm running. The brakes are positively wooden, but I'm used to that. Luckily, the Avon tires warm and scuff quickly, and keep me from worrying about grip--unless the back tire suddenly 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 forward 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, catapulting 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 into the groove despite my cramping legs. The thing is fast. But then I notice the temperature gauge as I head for the tri-oval; it's gone past 90 degrees Centigrade and is heading for 100, which Bigley called the danger zone. I imagine being flicked off into Turn 1 as the engine seizes, so I back off and roll into the pits a lap later, thinking unhappily that these might be my only laps till my race later in the day.

The crew goes over the bike while I head for the CCS office to double-check my race time. Two hours later we're pushing the bike to start/finish and the butterflies are swarming. Not because I'm worried about being competitive (I'm gridded last, and in a class filled with late-model R1s, GSX-Rs and ZX-10s!), but because I want the bike to last, want to make it back in one piece, want to bump right up against this thing's ragged edge and see what's there. Dunlop's race-tire guru Jim Allen walks by and gives me a thumb's up, but wonders privately about the bike's magnesium wheels, which are known to become brittle with age and disintegrate at speed. He keeps his concerns to himself, which is probably a good thing.

I take it easy at the start and use the first lap to get re-acquainted with the bike. My goal is simple: Run the thing as hard as I can, and hopefully catch a few backmarkers so the race feels like something more than a practice session. The TZ feels reasonably good entering the chicane on lap one so I carry extra speed through the exit and hammer the throttle. The bike shakes its head under power but remains true, and I've got myself a decent drive. I can hear the TZ's raspy exhaust note bouncing off the wall of the banking, and it sounds great. Time to see how fast this thing is. Ripping off the east banking a quarter of a mile later headed for start/finish, the bike bottoms forcefully on the roller bump at the banking's exit and goes into another speed wobble at what must be a buck-fifty. Roberts wasn't kidding.

The shimmy's not bad enough to cause me to back off, and I carry Big Speed past start/finish. But I blow the entrance to Turn 1, arguably the toughest bend in all of motor racing. Through the Horseshoe and the rest of the neutered infield I'm having a hell of a time getting any sort of rhythm going; the brakes are weak, the bike has little engine braking on deceleration, and though I'm riding a lot faster now than I had in practice, I'm lurching all over the place--and surely looking like an idiot on an old bike floundering at the back of the pack in the process.

The bike wants to wheelie through the gears exiting the infield onto the back straight, but I'm more worried about the oily mist that seems to be rising from around my crotch. I sneak a look down at my right thigh and knee and find the leather there shiny with petrochemicals. It's just the gas/oil mixture backwash through the carbs and intake system typical of most two-stroke racebikes, but I don't know that--and images of oil-coated rear tires begin playing on the insides of my eyelids. Pitching the bike into the chicane five seconds later at 90 or 100 mph takes mammoth faith, but there's no slide. Guess it's OK.

I try to get ready for the high-velocity shake/shimmy that's coming through the east banking's G-out, but my attention is focused on an almost unreal level of vibration and noise permeating the cockpit. It's way worse than I remember, so I naturally think something's gone terribly wrong. What's happening is that I'm riding the bike a lot faster now, and it's doing what big, nasty two-stroke racebikes do at speed. But again, I don't know this, all of which keeps me from nailing Turn 1 again. The temperature gauge again flirts with the 100-degree C mark, but I ignore it. Bigley said to.

By this time both my feet are asleep and buzzing with pins and needles due to reduced blood flow caused by my pretzeled legs, but there's too much craziness happening to think about them now. I get a bit overzealous exiting the Horseshoe, lose the back end in a lurid slide and almost run off the track after I get things buttoned up. The bike rockets toward the tight section of the infield and I nearly overshoot the right-hander due to my right hand cramping from grabbing the brake lever so hard for so long. I tell myself to relax, but my rapid-fire breathing fogs my shield and I miss my turn-in point two corners later. I can see folks in the grandstand as I rattle by, and I just know they're laughing their asses off.

I realize I'm tired and riding out of control--and then I get the crossed flags that signal the race's halfway point. still four laps to go? Damn! It's not so much the power that's making the TZ hard to ride; power hits hard at 7000 rpm and redlines at 11,000, so there's a decent spread there. The problem, for me at least, is that the engine is so much better than the chassis. The soft suspension, weak brakes and racklike ergos are taking their toll, making me ride spasmodically, unable to be smooth. Somehow I manage to relax a bit ripping along the banking, and I wonder briefly how riders--especially those larger than average--rode these things at race speeds for 200 miles here. Amazing.

In the race's latter stages I manage to put together a couple of decent laps, and even catch a few slower riders--although Team Yamaha's Jason DiSalvo and Jamie Hacking lap me toward the end while testing for the AMA races the following weekend. At the checkered flag I pull in and collapse onto the TZ's tank as I roll to a stop where Bodden is standing. Hacking and DiSalvo come over to check out the bike, as does Jim Allen, who then tells me of his concerns about the mag wheels. Someone says they got me at 168 mph on radar, which makes me extra happy the wheels stayed together. Hacking breaks us all up with his quip, "My mountain bike's got thicker fork tubes than that thing!" DiSalvo throws a leg over the TZ's saddle and fits perfectly; he says he'd like to try riding it sometime. Allen, who rode his share of race laps on big TZs, laughs at the thought. But we all know DiSalvo would be crazy-fast on the thing.

Bodden: I'm relieved afterward, just as I'd been 10 years earlier when I'd watched Boehm race the Drixton Honda 500 I'd prepared (the very reason we were having this 10-year commemoration at Daytona). I was afraid there might be some problem I didn't know about--and didn't have time to find--lurking deep within the TZ. I felt a great sense of privilege being able to work on one of the most legendary racing motorcycles of all time. The few moments I wasn't preoccupied during that long weekend, my head was filled with images of Agostini, Roberts, Johnny Ceccoto, Steve Baker, and, as a compatriot, of Patrick Pons and his win at this very circuit in 1980. I also reminisced about local greats, some champions, some not--Chambers, Rich Schlachter, Greg Smrz, et al. I reminded myself that, despite all the apprehension surrounding the TZ750's release, and despite its mind-boggling acceleration and top speed, it earned an enviable safety record. It may have been fierce, but it wasn't vicious.

Boehm: I'm spent, but hugely jazzed about the way it all came off. By riding the TZ hard in a real roadrace at Daytona, I'd gotten a firsthand glimpse into a large portion of American roadracing's history. Lentz's TZ wasn't quite the monster I expected. But the experience did show me the monstrous skill and determination of the riders who went fast on them back in the day. Amazing stuff. MC

By Patrick Bodden, Mitch Boehm
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