In 1988 I actually owned two 750 fours, both of 1982 manufacture, one a Honda CB750F, the other a Suzuki GSX750. The Honda came into my possession in 1987 with 44000 miles on the clock with no less than five previous owners in the logbook. The Suzuki came a year later and had endured less abuse, with only 18000 miles and two previous owners.
Interestingly, the differences between the bikes are smaller than you might suspect in hardware terms but on the road they are very different creatures. The Honda has the longer lineage, tracing its roots back to the late sixties and the original Japanese across the frame four. The GSX can only trace its ancestry back to 1977 when Suzuki switched from boring two strokes to state of art of four strokes, such as the GS750.
Quite how Suzuki suddenly managed to produce such a tough and reliable device as that GS750 is hard to figure but at a time when the original OHC CB750 was becoming fatter, slower and less reliable, the GS gave Honda the kick up the arse they needed to produce a new engine and chassis. It's quite easy to see in retrospect how the chassis of the two machines developed. Original Honda fours were renown for being a bit of a weaver and a wobbler so Honda went to some pains to stiffen up the frame and produce conservative geometry in the CB750KZ, the replacement for the ageing F2, which was quickly updated to the CB750F when everyone made fun of the KZ's appearance.
On the other hand, the GS series was long on stability and short on flickability. Suzuki changed both geometry and suspension which transformed the handling characteristics of the GSX. Whilst it was certainly much more throwable than the older machine it had become very sensitive to road and tyre condition. Twitchy is the word that springs to mind to describe its handling.
Both machines have old fashioned twin shock rear ends, although the GSX series was updated in '83 to monoshock. Both machines benefit from throwing these items away and fitting anything European. By coincidence both my machines were fitted with Marzocchis, the Honda sporting slightly longer shocks to improve ground clearance.
The CB came equipped with a set of Arrowmaxes that were worn down to the carcass. These inspired fear and loathing in the dry in a straight line, never mind trying to lean the damn thing over in the wet. They were replaced the next day with a new, expensive set of Michelins. The transformation was amazing. At least up to 90mph it was. Beyond that speed the Honda's stability goes to pot, it weaves gently at first then starts bouncing about all over the shop on fast A roads.
As the back Michelin only lasted 3500 miles, a set of Arrowmaxes was bunged on next after I'd been assured that they were the business when new by another CB owner. They certainly helped stability above the ton, but they slid much more under power in the wet. As soon as the tread was down to 2mm the handling went to hell again. The rear lasted 5000, the front 6750 miles.
The GSX was even more susceptible to tyres. It came with an odd mixture of obscure Far East rubber that weren't that bad in the dry, but the merest threat of rain had the bike sliding around like there was an oil slick between machine and road. I will never forget the first time they caught me out in the wet, I suddenly became aware that I was riding a heavy bike; generally, the GSX hides it 460lbs better than the CB does its 520lbs. I had to proceed with both feet down at less than 10mph!
I soon fitted a set of Avon Venoms, again recommended by another owner. They seemed to suit the bike well, quietening down the steering a bit and promoting high speed stability. Despite the bike's propensity for the odd bit of wheelspin during GP starts, these lasted quite well - 6000 miles rear, 8000 miles front. Perhaps down to the lighter weight of the Suzuki.
I found it strange that the Suzuki which felt twitchy at low speeds rarely weaved nastily at high speeds, whilst the Honda which was stable below 90mph could wobble badly once the speedo flirted with the ton mark. It is true, I suppose, that the handling characteristics matched the power delivery of the two machines.
Both engines were of the DOHC type and could, at first glance, have been produced by the same factory. The Suzuki has both more power and a wider spread of it. However, the Suzki engine thrives on revs, below 5000rpm it lack the civility of the Honda, clattering and vibrating slightly. Come seven grand it gathers it skirts and takes off like a mad thing - it is fitted with a Motad 4-1 so I can't say if this is true of the standard machine or not.
The Honda was running on stock, albeit slightly rotted, exhausts, the motor was happiest between 3000 and 7000 revs, finding its forte as either an 85-90mph cruiser or as a laid back means of circumventing A roads. For sure, the throttle could be twisted open and it could almost match the Suzuki's top speed of 130mph but the machine felt distinctly unhappy. Much beyond 7000rpm produces piercing secondary vibes and a ridiculous amount of valve noise, not to mention frightening handling characteristics.
It has to be recalled, though, that the Honda engine now has over 60,000 miles on the clock and has probably been mistreated and neglected in the past, whereas the Suzuki boasts just 29000 miles and judging by its appearance has been well cared for. If those situations were reversed it might well be that the Honda would have the superior power characteristics. Such are vagaries of the secondhand market that a decent test ride of the machine on offer is the only way to determine its value.
Even with its greater abuse I often find the Honda the better machine to ride, there is just something about it, as if its longer ancestry insists on breaking through its inferior specification, demanding from its rider respect and admiration. More prosaically, I have been stopped twice for speeding on the Suzuki and never on the Honda, the CB is a machine that is happy to potter whereas the GSX demands a huge grin, a wild right hand and hard blue eyes.
The Honda's engine has required much more attention than the Suzuki's, although, perhaps strangely, the Honda's valves but rarely need attention whereas I seem to be resetting the GSX's every other week. The first problem with the Honda was when the gearbox started playing up. The sudden way I would find myself in a false neutral when leant over or in the process of overtaking scared the shit out of me!
When I split the crankcases - after taking a day off to recover after removing the massive engine - I found a bit of a mess, worn gear cogs and a bent selector. That the gear change shaft seal was bashed about and covered in Araldite indicated that some time in the past it had leaked oiled copiously and perhaps drained the engine of oil. There was no movement in the crankshaft so the damage was at least limited. The bits were acquired from the local breaker who didn't believe I would be able to fix something as complicated as a gearbox - it went back together okay and has worked perfectly ever since.
Well, not perfect. I suspect it was clunky from new and difficult to achieve clean changes. It's always liked to go straight from third to a false neutral rather than fourth when changing up with the revs poured on high. My feeling of horror when this happens can only be matched by the engine's, although I have yet to tangle any of the valves. By contrast, The Suzuki's box is smooth and precise, although of late I have noticed a tendency to go into a false neutral when changing down from fifth to fourth and fourth to third.
The Suzuki also has the lighter clutch with more feel, but at 25000 miles I had to put in some new plates, so its friendliness is not without a price. The Honda's clutch is so heavy that in town I tend to leave the bike in second or third, just using engine revs to control the bike - the Honda does have better engine braking, enough stopping power available by just backing off the throttle to forget the brakes in town.
Perhaps because they have had so much trouble in the past, Honda devised a curious means of driving the camshafts. They are connected by a single chain running between the camshafts, whilst another chain drives one camshaft from the crankshaft. That Honda were able to reliably run DOHCs using just one chain as long ago as 1965 might make this artifice appear suspect, and so it turned out. I've had to replace the tensioner mechanism twice and the camchains once - admittedly, I used secondhand parts so only have myself to blame for the second job. How many camchains the Honda has gone through is anyone's guess. The rattle is immediately obvious when the camchain goes.
Suzuki have never had much trouble with their auto-tensioners or camchains and the GSX lived up to this tradition, despite the fact that at tickover it has always rattled as if something was shot. I always found it very difficult to balance its four carbs which may not have helped low rev quietness for the engine became noticeably less noisy once the throttle was opened up. The Honda, by the way, despite its greater mileage required little attention to the carbs, once set they stayed in balance.
Where the Honda's electrics were exemplary in their reliability, shortly after I secured ownership of the Suzuki it lived up to its reputation for shoddy electrics. I've owned a GS400 in the past which displayed exactly the same symptom - a battery that refused to charge up fully. On the GS I had just run it until the whole electrical system was burnt out, only then had I expensively had to replace everything.
With the GSX I acted immediately. The source of the problem was no more than a burnt out coil in the alternator. I had the rectifier/regulator checked out and it was fine. If I had left it much longer I am sure that it would have been affected. An exchange alternator cost £30 and much to my surprise arrived on my doorstep a mere three days after I'd despatched the old one and the cheque. No further electrical problems have occurred.
Both bikes have experienced similar problems with their brakes. Both have twin discs out front and a single rear. Both have problems in the wet - the Suzuki's are too powerful and insensitive with a gut wrenching tendency to lock up the wheels whereas the Honda's suffer from wet weather lag and when they do decide to work scream and wail like a pig being slaughtered. As I tend not to ride on the brakes, neither bike has required replacement of their pads but both need half yearly strip downs of their calipers.
I have found that the Honda has tougher alloy with screws and bolts that don't strip or bend or snap as easily as the Suzukis. Thus, the first time I tried to strip the rear caliper on the GSX I was not that surprised to find my knuckles covered in blood and a pile of snapped screws and bolts littering the floor. The amount of effort involved in keeping both machines' brakes in good shape is too tedious and depressing to go into here, just thinking about it makes me want to grab a 5lb hammer and bash the damn things into a million pieces...
The worst thing that happened on the Suzuki was when the petrol tank started leaking where it met the seat. I had noticed the rust but done little about it as I could only see the red stuff when the seat was open. At the time I was 200 miles from home heading for the Continent for two weeks holiday, so I was not amused. Fortunately, Shit City was not far away and I already had bought stuff from one breaker who had broken a few GSXs - apparently a lot get blown up when the crank twists under the pressures of drag racing.
By the time I reached the breakers my trousers were full of petrol and the machine was coughing and spluttering. It would only have taken some idiot to fling a cigarette out of a car window to turn me into a raging inferno. I thought the breaker was amazingly friendly when he offered me a tank for £20 and threw me the keys for his flat to get cleaned up. Too good to be true, the bastard jumped me while I was in the shower and I only fended off his advances by kneeing him between the legs. He was hung like a stallion and I doubt if I would ever have walked properly again if he had got the better of me! Ugh!
Apart from that, er, adventure the Continental trip was a great success. Some days I just sped everywhere as quickly as possible, other days I just relaxed and didn't use the bike at all. The only thing I did to the GSX in 2000 miles was change the oil twice and adjust the chain every 200 miles. I would have taken the Honda but I hadn't checked out the engine properly after replacing the camchain, so put my trust in the robust Suzuki instead. Chain wear on the latter was terrible (4000 miles) and on the Honda almost acceptable (7000 miles) although to be fair the Suzuki didn't need a sprocket change whereas the Honda's sprockets wore out almost as fast as the chain.
The Suzuki was the better on fuel if you could persuade yourself to ride it at the Honda's preferred speed. But as this was rare, they worked out pretty much the same at 35 to 40mpg. That figure was appalling for the Honda as it was ridden moderately but acceptable for the Suzuki as the balls were revved off the engine and it had a grin factor approaching ten when you were in the mood. Just why the Honda should be so bad is open to question, perhaps its engine was worn out, perhaps it was just too heavy or perhaps someone had not paid attention to efficiency when designing the combustion chamber.
If you were silly enough to neglect the oil level between oil changes, the result would be a seized engine as both motor consumed oil. On the overrun there was a hint of smoke out of the silencers on the Honda, indicative that its valves or rings were on the way out; its greater mileage an explanation for its greater need for oil. The Honda needed a pint every 250 miles, the Suzuki would go for 400 miles before needing the same amount. I used cheapo Shell 20/50 in both bikes to no apparent ill effect, but I made damn sure it (and the filter) was changed every 1000 miles. After that kind of mileage, cheap oil quickly degenerates whereas the much more expensive stuff is more resistant.
I did find that if the Suzuki was left standing for more than a month its oil emulsified whereas no such problem occurred in the Honda. A white layer formed on the inside of the Suzuki's sight glass making it extremely difficult to gauge the correctness of the oil level after it had been changed. Fortunately, a fast bash cleared the white stuff away but it was strange that the same oil should react so differently in the two machines.
If I had to chose one machine out of the two it would be the Suzuki, simply because its engine has been subjected to much less abuse and promises to last longer. If the choice was between two machines of similar mileage and condition I would chose the Honda, for I find it more relaxed and less licence endangering. If I was 20 instead of 30, I would probably reverse that choice and go wild on the Suzuki.
Examples of both machines in good condition, featuring sensible mods to suspension and chassis, are available for well under a grand in the private market. Some care is needed with the Honda to avoid the camchain and gearbox problems, so if you know little about engines the Suzuki would be the safer bet. They are both a bit of a handful if you're coming straight from a 125, each is quite capable of spitting off people who don't know what they are doing and both have the kind of conservative but butch looks you either love or hate.
Anon