Post by Pardee on Jun 25, 2014 13:10:13 GMT -5
Yamaha's new big one is not a punched-out 650; the forty-five incher has a form and character all its own: refined, smooth, commfortable and supremely pastel.
Cycle, March 1973
It isn't fast enough to be accorded the designation Superbike, but with a quarter-mile speed of just over 97 mph it is one of the ten fastest production motorcycles in the world. It isn't particularly handsome, those in charge of its appearance having laid down their pencils and sat back in their chairs a few minutes and a few fillagrees on the wrong side of Enough. Yet its proportions are Japanese Classic and one would have a difficult time defending the statement that the bike is unattractive. Like most motorcycles sentenced to a weight of over 500 pounds, it lumbers a little through the mountains, but it doesn't lumber enough to be frightening. On the open road at a sustained 70 mph it is comfortable, but not surpassingly so (unlike bikes like the Moto Guzzi, an Interstate Armchair if ever there was one). Possessed of the most advanced two-cylinder engine in motorcycling and a few other features which are totally unique in the sport, a rational rider reaction would be, "Uh-huh. Nice." An extended trip leaves the rider with a multitude of impressions of where he's been, and no impressions whatsoever of what he's been there on. It's not fast, not slow, neither handy nor awkward, visually between striking and overcooked, neither expensive enough to drop your jaw nor cheap enough to be disposable. It is rational, reliable, quiet [85 dB(A)], elaborate, and entirely serviceable; the 1973 Yamaha TX750 is the Chevrolet Biscayne of big-bore motorcycling. It gives you nothing to put up with--and no reason for doing so if it did.
Understand that the Biggest Yamaha is not derivative, the way the Triumph Hurricane is an amplification of the Trident (or BSA) triple theme, the Super Glide a McNasty 74, or the Honda CB-500 a scaled-down version of the relentlessly successful 750 Four. No. The TX750 shares nothing more than a few transmission parts with the TX650 (formerly the XS2), suggesting (1) that Yamaha is as serious as they can be with the bike, and (2) in all liklihood it'll be around for a while. A stop-gap move until the injected four-cylinder water-cooled two-stroke shows up? Not in a million years. Judging from the unbelievable complexity of this twin, Yamaha has a wad tied up in the 750's tooling, and indications are that what you see here is what you'll be getting for some time to come. They may make it bigger in 1974 or 1975 in an effort to maintain or improve performance levels while at the same time reducing emissions and cutting down on noise, but the odds are that the TX750 is the beginning of a fresh approach rather than the capstone of a traditional one.
Viewing the swelling multi-cylinder offerings of the enemy camps (Honda: 3 fours, Kawasaki 1 Four and four Threes, Suzuki 3 Threes, Triumph 2 Threes) Yamaha has opted for a refounding of the Twin concept. Their logic: two cylinders are less complex than four, two cylinders are cheaper than four, two cylinders are narrower than four, two cylinders are lighter than four. But two parallel cylinders vibrate more than four, which is the problem at the very soul of the New Approach. Yamaha solves the problem with an intricate assortment of chains, shafts, bearings, and bobweights, and it can be said that it works without question. Yamaha calls it the Omni-Phase Balancing System, and the rumor is that it is the brainchild of a single engineer who pressed for it for years and finally achieved enough rank to make it stick. Whatever, now there are two (and only two) big-bore parallel vertical twins that do not vibrate: the Norton Commando and the TX750. Norton's solution is an external one: let the sucker shake, but keep the vibration impulses away from the rider. Yamaha's is internal: absorb the vibration before it gets out of the engine.
How the Omni-Phase works, fundamentally: for every action there is an equal, and opposite, reaction. With two pistons roaring up and down the bores there is a lot of action. Most of the reaction is absorbed by weight differentials machined into the crank assembly. But not all. Those little pulses that escape from the flywheel are the pulses that, on most Big Twins, make your hands tingle and put your feet to sleep. They are the pulses that must be absorbed. Imagine one unit of vibration--one single force, shuddering in solitary splendor out of the bowels of the engine, headed towards the front of the motorcycle. Now imagine that the engine is also able to generate another single force, equal in power to the first one, only headed towards the rear of the motorcycle at exactly the same time the first one takes off towards the front. The result? The second single force, an equal force in an opposite direction, nullifies the first one, so that beyond all the thrashing and arguing going on between these two forces nothing ends up going anywhere. The first force makes the engine want to move towards the front; the second wants to make it move towards the rear. Between the two of them the engine stays right where it is, neither moving forward nor back, no little pulses escape, and no vibration is the result.
In reality it is slightly more complicated than that, one reason being that there is a force exerted on the crankshaft by the balancer, which means there must be yet another force generated to absorb it. This Yamaha does by including still another bobweight, rotating in the same direction as the crankshaft.
What is laudable when you consider the complexity of Yamaha's approach is that all those chains, shafts, bobweights, etcetera are contained in a set of crankcases not notably larger than the cases of the older, and unbalanced, XS2. Access to the mechanism is through a finned aluminum "pan" bolted to the belly of the horizontally-split crankcases; drop the pan and you see that the two balancing bobweights are bolted to shafts mounted in bosses in the case and rotating in needle bearings. An endless chain passes from the drive sprocket in the middle of the crankshaft over a sprocket splined to the balance-weight that rotates in the same direction as the crankshaft, and then under the counter-rotating drive-sprocket is check-to-jowl with the sprocket that drives the overhead cam. Representatives of Yamaha International admit that they are engaged in a massive education program for their dealers, and that it is critical that all the balancer units and chains be correctly phased. For the price of compactness is hairbreadth clearances; mess up by as much as a tooth either way and not only will the engine vibrate, there is a good chance that the bobweights will foul each other.
Once beyond the sub-transmission-located balancer apparatus the TX750 twin continues to be engaging. For one thing, the 750 stands as a departure in that it uses automotive-type two-piece connecting rods swinging on insert plain-bearings; three plain bearings are also used to support the crank, a one-piece forged affair. Ain't a needle, roller, or ball-bearing anywhere in sight, which means (1) that crankshaft and bearing repair and replacement can the more easily be handled by the dealer and (2) all of a sudden we're back to automotive-type high-pressure oiling systems, plain bearings needing more pressure and more volume to carry away the increase in heat generated by such an arrangement. A dual-stage trochoidal pump, mounted on a shaft driven by gear by the crankshaft through the primary drive, uses one element to pressure-feed the crank assembly, rods and pistons, and top end. After doing what it was supposed to, the oil is picked up by the scavenging element; part is forced past and through the transmission, clutch, and balancer apparatus and back to the oil strainer beneath the crank, and part returns directly to the tank.
This transverse shaft has more to do than run the oil pumps; it is also used to open and close the points, which are located beneath the left side-cover. The points do not have a cover of their own; our test machine was delivered with enough moisture in the vicinity of the contact breakers to keep it from running at all, so we found out the hard way that to get at the mechanism you have to remove the shift lever, which means that you have to loosen the footpeg mounting bolt, which is more of a hassle than necessary, and not improved by the fact that the footpeg mounting bolt also serves as an engine mounting bolt. Despite it all Yamaha has followed in the tracks of Suzuki by not having the contact breaker assembly run directly off the end of the crankshaft, which means that the ignition timing is not free to wander around at high engine speeds due to crankshaft flexure.
Upstairs the traditional overhead cam, chain-driven by the crank, works the valves through adjuster-equipped rockers. Like the Kawasaki Z-1 the TX750 has begun to deal with the future in terms of emission control: compression ratio is 8.4-1, the exhaust valve seats are of a special alloy, and just as quick as you can say Donald Dirtyair the TX can live with low-lead, low-test, or lead-free gasoline. Said gasoline is fed in through a pair of 32mm Solex-Mikuni diaphram carburetors which meter fuel-air mixture on the basis of what the engine needs to do what you want it to, rather than what you want the carburetors to do. And Yamaha has done its best to duplicate the easy air-filter servicing introduced by Honda and duplicated by Kawasaki's Z-1; but instead of lifting the seat and plucking the element out, the Yamaha demands that you wrench loose the 10-mm bolt securing the side cover and then release the airbox door by removing a pair of Phillips-head screws. Then the tin, rubber-sealed air filter element can be removed and cleaned. Other maintenance hassles: the cylinderhead and cylinder assemblies cannot be removed without first removing the engine from the frame, despite a pair of bows in the frame rails passing directly over the cam-cover.
Unlike the Yamaha 650, the TX750 has a straightforward electric starting arrangement. The 650 lifted one of its exhaust valves when the starter lever was operated; the 750's button simply calls into play a front-mounted motor that spins the crank through a clutching system. But while other electric starters tend to connect with the crank through a gear or a series of gears, the TX750 does it by chain--which means the engine has another chain, and another tensioner, added to an already impressive collection of hardware.
Once the water-in-the-points problem was attended to with a few well-directed blasts of compressed air the TX750 was an instantaneous starter for as long as we had it, and it settled to an absolutely even-beat idle in a matter of seconds. It's the most extraordinary idle you ever heard; each exhaust pulse flits out the pipe exactly when it should. No loping, no variation in exhaust pulse intensity, just poppoppoppop, suggesting that the cam timing isn't terribly radical and that both CV carburetors are performing accurately. And despite the fact that the engine has to accelerate those balancers as well as its own crank, cam, and so on, throttle response is appealingly rapid, and just sitting there idling, the big, metalflake-tan dude doesn't vibrate. Moving from a halt is no big deat one way or the other; the clutch feels like a clutch, the delicacies of the transmission sheltered by a series of concentrically disposed springs in the clutch housing. It only becomes a big deal when you try to move out fast, with a lot of throttle. When that happens the clutch gets snatchy and abrupt, going from disengaged to engaged with about a quarter-inch of travel at the clutch lever. Once underway everything works as nicely as you would expect from a $1554 motorcycle from Yamaha; the transmission's five broadly-spaced ratios are where a touring rider would like them, the seat is comfortable enough, the handlebars and the footpegs are where they ought to be to reduce fatigue, and glory gee to Besus, it really is smooth for a twin. Four thousand in top gives just under 60 mph, and at 5000 you're tootling along around 75. Steering geometry identical to that on the XS650 (27 degree of rake, 3.9 inches of trail) gives predictable gentle handling with just a hint of imprecision as the bike is brought to an attitude of extreme lean from an attitude of moderate lean, but it's nothing alarming, especially when you consider that the costume it wears best is that of Freeway Floater. It can countenance those cherry, buoyant backroads, but it doesn't like to deal with them at speed, especially the smooth mountain-darters that tax its suspension components to unhappy limits. Ground clearance, however, is not a problem; nothing drags going around right-handers. And the foot of the sidestand, while a nuisance initially, can be rapidly worn down to suit the far reaches of your courage and ability.
And bless its heart, the 750 Yamaha abounds with what are known as "features." Electric starting is a feature. The Omni-Phase is a feature. The front disc brake (a dual-live-puck system, like that on the 650) is a feature. The cast exhaust balancer, bolted to the exhaust ports, is a feature. And so is the vane-type steering damper, found on this year's Yamahas from 250cc up.
But the trickiest features of all are three indicator lamps between the two instruments. The one on top, the white one, tells you when your headlight is in trouble, the one in the middle below monitors rear brake lining material, and the one on the right below glows warmly whenever the stoplight goes on, and blinks hysterically when it doesn't and is supposed to. Only an abject cynic would dismiss Yamaha's efforts here as being sales, rather than safety, oriented, but it does strike us that a red instrument light that comes on when things are working satisfactorily might be a bit much, especially when the same light flashes when things get out of whack. Even so it is to be hoped that Yamaha presses ahead with the development of its warning lights. How many of us, after all, actually check the condition of our brake lining material.
Unquestionably the TX750 is a sound motorcycle; while we had it, except for the water-in-the-electrics gremlin, it did absolutely nothing wrong. It always started. It always stopped. It was comfortable. It steered OK. It didn't freak out the populace with a lot of boomy exhaust noise, it delivered a satisfactory 36.6 miles per gallon, it used little oil and leaked none. The exhaust pipes didn't turn blue. It appears flashier and gaudier than it has to be, with just a little too much doo-dah on the tank and the kind of paint scheme and color selection suggestive of razzle-dazzle rather than elegance and substance; yet it is not an ugly motorcycle. But if it is inspired in technical accomplishment such accomplishment has been brought to bear on an unemotional concept: a big-bore, four-stroke, parallel twin. It won't be tracking a lot of mud into the souls of its owners because unless something wierd happens; the bike should be as tough and as reliable as anything on the market. But by the same token its faithful owners aren't likely to get all excited and circle the wagons around the TX750 either, because the bike does not, in all its pastel cold-bloodedness, blaze the mind with evocations of the unique, or swell the chest with pride of ownership.
The 750 Yamaha is a good choice for those enthusiasts whose enjoyment of motorcycling depends upon soaking up the scenery--and whose interest in the machinery of the sport is quite secondary. Indeed some riders are indifferent to hardware.
As a conveyance it is practically flawless; as an engineering exercise it is a success without doubt. But ultimately you're left with, "Uh-huh. Nice."
Cycle, March 1973
It isn't fast enough to be accorded the designation Superbike, but with a quarter-mile speed of just over 97 mph it is one of the ten fastest production motorcycles in the world. It isn't particularly handsome, those in charge of its appearance having laid down their pencils and sat back in their chairs a few minutes and a few fillagrees on the wrong side of Enough. Yet its proportions are Japanese Classic and one would have a difficult time defending the statement that the bike is unattractive. Like most motorcycles sentenced to a weight of over 500 pounds, it lumbers a little through the mountains, but it doesn't lumber enough to be frightening. On the open road at a sustained 70 mph it is comfortable, but not surpassingly so (unlike bikes like the Moto Guzzi, an Interstate Armchair if ever there was one). Possessed of the most advanced two-cylinder engine in motorcycling and a few other features which are totally unique in the sport, a rational rider reaction would be, "Uh-huh. Nice." An extended trip leaves the rider with a multitude of impressions of where he's been, and no impressions whatsoever of what he's been there on. It's not fast, not slow, neither handy nor awkward, visually between striking and overcooked, neither expensive enough to drop your jaw nor cheap enough to be disposable. It is rational, reliable, quiet [85 dB(A)], elaborate, and entirely serviceable; the 1973 Yamaha TX750 is the Chevrolet Biscayne of big-bore motorcycling. It gives you nothing to put up with--and no reason for doing so if it did.
Understand that the Biggest Yamaha is not derivative, the way the Triumph Hurricane is an amplification of the Trident (or BSA) triple theme, the Super Glide a McNasty 74, or the Honda CB-500 a scaled-down version of the relentlessly successful 750 Four. No. The TX750 shares nothing more than a few transmission parts with the TX650 (formerly the XS2), suggesting (1) that Yamaha is as serious as they can be with the bike, and (2) in all liklihood it'll be around for a while. A stop-gap move until the injected four-cylinder water-cooled two-stroke shows up? Not in a million years. Judging from the unbelievable complexity of this twin, Yamaha has a wad tied up in the 750's tooling, and indications are that what you see here is what you'll be getting for some time to come. They may make it bigger in 1974 or 1975 in an effort to maintain or improve performance levels while at the same time reducing emissions and cutting down on noise, but the odds are that the TX750 is the beginning of a fresh approach rather than the capstone of a traditional one.
Viewing the swelling multi-cylinder offerings of the enemy camps (Honda: 3 fours, Kawasaki 1 Four and four Threes, Suzuki 3 Threes, Triumph 2 Threes) Yamaha has opted for a refounding of the Twin concept. Their logic: two cylinders are less complex than four, two cylinders are cheaper than four, two cylinders are narrower than four, two cylinders are lighter than four. But two parallel cylinders vibrate more than four, which is the problem at the very soul of the New Approach. Yamaha solves the problem with an intricate assortment of chains, shafts, bearings, and bobweights, and it can be said that it works without question. Yamaha calls it the Omni-Phase Balancing System, and the rumor is that it is the brainchild of a single engineer who pressed for it for years and finally achieved enough rank to make it stick. Whatever, now there are two (and only two) big-bore parallel vertical twins that do not vibrate: the Norton Commando and the TX750. Norton's solution is an external one: let the sucker shake, but keep the vibration impulses away from the rider. Yamaha's is internal: absorb the vibration before it gets out of the engine.
How the Omni-Phase works, fundamentally: for every action there is an equal, and opposite, reaction. With two pistons roaring up and down the bores there is a lot of action. Most of the reaction is absorbed by weight differentials machined into the crank assembly. But not all. Those little pulses that escape from the flywheel are the pulses that, on most Big Twins, make your hands tingle and put your feet to sleep. They are the pulses that must be absorbed. Imagine one unit of vibration--one single force, shuddering in solitary splendor out of the bowels of the engine, headed towards the front of the motorcycle. Now imagine that the engine is also able to generate another single force, equal in power to the first one, only headed towards the rear of the motorcycle at exactly the same time the first one takes off towards the front. The result? The second single force, an equal force in an opposite direction, nullifies the first one, so that beyond all the thrashing and arguing going on between these two forces nothing ends up going anywhere. The first force makes the engine want to move towards the front; the second wants to make it move towards the rear. Between the two of them the engine stays right where it is, neither moving forward nor back, no little pulses escape, and no vibration is the result.
In reality it is slightly more complicated than that, one reason being that there is a force exerted on the crankshaft by the balancer, which means there must be yet another force generated to absorb it. This Yamaha does by including still another bobweight, rotating in the same direction as the crankshaft.
What is laudable when you consider the complexity of Yamaha's approach is that all those chains, shafts, bobweights, etcetera are contained in a set of crankcases not notably larger than the cases of the older, and unbalanced, XS2. Access to the mechanism is through a finned aluminum "pan" bolted to the belly of the horizontally-split crankcases; drop the pan and you see that the two balancing bobweights are bolted to shafts mounted in bosses in the case and rotating in needle bearings. An endless chain passes from the drive sprocket in the middle of the crankshaft over a sprocket splined to the balance-weight that rotates in the same direction as the crankshaft, and then under the counter-rotating drive-sprocket is check-to-jowl with the sprocket that drives the overhead cam. Representatives of Yamaha International admit that they are engaged in a massive education program for their dealers, and that it is critical that all the balancer units and chains be correctly phased. For the price of compactness is hairbreadth clearances; mess up by as much as a tooth either way and not only will the engine vibrate, there is a good chance that the bobweights will foul each other.
Once beyond the sub-transmission-located balancer apparatus the TX750 twin continues to be engaging. For one thing, the 750 stands as a departure in that it uses automotive-type two-piece connecting rods swinging on insert plain-bearings; three plain bearings are also used to support the crank, a one-piece forged affair. Ain't a needle, roller, or ball-bearing anywhere in sight, which means (1) that crankshaft and bearing repair and replacement can the more easily be handled by the dealer and (2) all of a sudden we're back to automotive-type high-pressure oiling systems, plain bearings needing more pressure and more volume to carry away the increase in heat generated by such an arrangement. A dual-stage trochoidal pump, mounted on a shaft driven by gear by the crankshaft through the primary drive, uses one element to pressure-feed the crank assembly, rods and pistons, and top end. After doing what it was supposed to, the oil is picked up by the scavenging element; part is forced past and through the transmission, clutch, and balancer apparatus and back to the oil strainer beneath the crank, and part returns directly to the tank.
This transverse shaft has more to do than run the oil pumps; it is also used to open and close the points, which are located beneath the left side-cover. The points do not have a cover of their own; our test machine was delivered with enough moisture in the vicinity of the contact breakers to keep it from running at all, so we found out the hard way that to get at the mechanism you have to remove the shift lever, which means that you have to loosen the footpeg mounting bolt, which is more of a hassle than necessary, and not improved by the fact that the footpeg mounting bolt also serves as an engine mounting bolt. Despite it all Yamaha has followed in the tracks of Suzuki by not having the contact breaker assembly run directly off the end of the crankshaft, which means that the ignition timing is not free to wander around at high engine speeds due to crankshaft flexure.
Upstairs the traditional overhead cam, chain-driven by the crank, works the valves through adjuster-equipped rockers. Like the Kawasaki Z-1 the TX750 has begun to deal with the future in terms of emission control: compression ratio is 8.4-1, the exhaust valve seats are of a special alloy, and just as quick as you can say Donald Dirtyair the TX can live with low-lead, low-test, or lead-free gasoline. Said gasoline is fed in through a pair of 32mm Solex-Mikuni diaphram carburetors which meter fuel-air mixture on the basis of what the engine needs to do what you want it to, rather than what you want the carburetors to do. And Yamaha has done its best to duplicate the easy air-filter servicing introduced by Honda and duplicated by Kawasaki's Z-1; but instead of lifting the seat and plucking the element out, the Yamaha demands that you wrench loose the 10-mm bolt securing the side cover and then release the airbox door by removing a pair of Phillips-head screws. Then the tin, rubber-sealed air filter element can be removed and cleaned. Other maintenance hassles: the cylinderhead and cylinder assemblies cannot be removed without first removing the engine from the frame, despite a pair of bows in the frame rails passing directly over the cam-cover.
Unlike the Yamaha 650, the TX750 has a straightforward electric starting arrangement. The 650 lifted one of its exhaust valves when the starter lever was operated; the 750's button simply calls into play a front-mounted motor that spins the crank through a clutching system. But while other electric starters tend to connect with the crank through a gear or a series of gears, the TX750 does it by chain--which means the engine has another chain, and another tensioner, added to an already impressive collection of hardware.
Once the water-in-the-points problem was attended to with a few well-directed blasts of compressed air the TX750 was an instantaneous starter for as long as we had it, and it settled to an absolutely even-beat idle in a matter of seconds. It's the most extraordinary idle you ever heard; each exhaust pulse flits out the pipe exactly when it should. No loping, no variation in exhaust pulse intensity, just poppoppoppop, suggesting that the cam timing isn't terribly radical and that both CV carburetors are performing accurately. And despite the fact that the engine has to accelerate those balancers as well as its own crank, cam, and so on, throttle response is appealingly rapid, and just sitting there idling, the big, metalflake-tan dude doesn't vibrate. Moving from a halt is no big deat one way or the other; the clutch feels like a clutch, the delicacies of the transmission sheltered by a series of concentrically disposed springs in the clutch housing. It only becomes a big deal when you try to move out fast, with a lot of throttle. When that happens the clutch gets snatchy and abrupt, going from disengaged to engaged with about a quarter-inch of travel at the clutch lever. Once underway everything works as nicely as you would expect from a $1554 motorcycle from Yamaha; the transmission's five broadly-spaced ratios are where a touring rider would like them, the seat is comfortable enough, the handlebars and the footpegs are where they ought to be to reduce fatigue, and glory gee to Besus, it really is smooth for a twin. Four thousand in top gives just under 60 mph, and at 5000 you're tootling along around 75. Steering geometry identical to that on the XS650 (27 degree of rake, 3.9 inches of trail) gives predictable gentle handling with just a hint of imprecision as the bike is brought to an attitude of extreme lean from an attitude of moderate lean, but it's nothing alarming, especially when you consider that the costume it wears best is that of Freeway Floater. It can countenance those cherry, buoyant backroads, but it doesn't like to deal with them at speed, especially the smooth mountain-darters that tax its suspension components to unhappy limits. Ground clearance, however, is not a problem; nothing drags going around right-handers. And the foot of the sidestand, while a nuisance initially, can be rapidly worn down to suit the far reaches of your courage and ability.
And bless its heart, the 750 Yamaha abounds with what are known as "features." Electric starting is a feature. The Omni-Phase is a feature. The front disc brake (a dual-live-puck system, like that on the 650) is a feature. The cast exhaust balancer, bolted to the exhaust ports, is a feature. And so is the vane-type steering damper, found on this year's Yamahas from 250cc up.
But the trickiest features of all are three indicator lamps between the two instruments. The one on top, the white one, tells you when your headlight is in trouble, the one in the middle below monitors rear brake lining material, and the one on the right below glows warmly whenever the stoplight goes on, and blinks hysterically when it doesn't and is supposed to. Only an abject cynic would dismiss Yamaha's efforts here as being sales, rather than safety, oriented, but it does strike us that a red instrument light that comes on when things are working satisfactorily might be a bit much, especially when the same light flashes when things get out of whack. Even so it is to be hoped that Yamaha presses ahead with the development of its warning lights. How many of us, after all, actually check the condition of our brake lining material.
Unquestionably the TX750 is a sound motorcycle; while we had it, except for the water-in-the-electrics gremlin, it did absolutely nothing wrong. It always started. It always stopped. It was comfortable. It steered OK. It didn't freak out the populace with a lot of boomy exhaust noise, it delivered a satisfactory 36.6 miles per gallon, it used little oil and leaked none. The exhaust pipes didn't turn blue. It appears flashier and gaudier than it has to be, with just a little too much doo-dah on the tank and the kind of paint scheme and color selection suggestive of razzle-dazzle rather than elegance and substance; yet it is not an ugly motorcycle. But if it is inspired in technical accomplishment such accomplishment has been brought to bear on an unemotional concept: a big-bore, four-stroke, parallel twin. It won't be tracking a lot of mud into the souls of its owners because unless something wierd happens; the bike should be as tough and as reliable as anything on the market. But by the same token its faithful owners aren't likely to get all excited and circle the wagons around the TX750 either, because the bike does not, in all its pastel cold-bloodedness, blaze the mind with evocations of the unique, or swell the chest with pride of ownership.
The 750 Yamaha is a good choice for those enthusiasts whose enjoyment of motorcycling depends upon soaking up the scenery--and whose interest in the machinery of the sport is quite secondary. Indeed some riders are indifferent to hardware.
As a conveyance it is practically flawless; as an engineering exercise it is a success without doubt. But ultimately you're left with, "Uh-huh. Nice."