The only problem with the GS range is that their toughness makes them very popular, with few low mileage ones left on the market. I was willing to spend up to a grand and take my chances with an engine that had up to 50000 miles on the clock. After several false calls and a couple of near misses I finally tracked down a '79 GS750 that'd done a mere 29000 miles under the gentle hands of an elderly owner. This was three years ago and at a cost of £700 it seemed like a dream buy.
The bike had some sensible mods. Roadrunner tyres, Goodridge hose, Ferodo pads, Motad four into one exhaust, K&N filters, Koni shocks, fork brace, full chain enclosure, O-ring chain conversion, stainless steel mudguards and a 2:4 seat. The owner happily admitted to having a generator burn out but having no more problems with the rewound alternator and Superdream rectifier/regulator.
The powerful Cibie headlamp conversion blasted a path through the dark country roads as I rode home, thrilled by the drone from the exhaust and the surge of power from 6000 revs onwards. There was a tight, purposeful feel to the chassis, an instant communion with the bike possible thanks to low bars and rear-sets. The linkage set-up for the gearbox rendered the change rather vague but I thought it was something that I could soon grow used to.
The next morning I looked the machine over again. The paint was a little faded, the engine alloy scarred with corrosion and the back disc a bit corrugated with wear. There was no sign of oil leaks, not even from the cylinder head gasket, and the engine ticked over at 1000 revs without even the hint of clutch rattle. With an engine that developed only 70 horses, four carbs were a bit over the top but I found they would stay in balance for a minimum of 5000 miles.
A new machine always takes a bit of time to understand, to find its limits and the things that you definitely shouldn't do. The GS was a breeze, with its neutral steering and broad range of power anyone used to a 250 would soon adapt. It does weigh 500Ibs but feels a lot lighter once under way. The only time the GS was a pig was when backing out of the garage or a parking spot, a combination of the dreaded dragging discs and its mass. One pleasant side effect of all the, mass was that the secondary vibes were, to a large degree, absorbed.
I've ridden 550 fours that had more of abuzz to them, the overall effect of the GS750 being one of pure civilisation, the motor giving off an overwhelming impression of good build quality. OK, I will admit that once beyond 9500rpm the footpegs did shake a little but only took the motor to those revs for the briefest of intervals when road and traffic conditions demanded I make the best use of the available acceleration. Only a fool would continuously cane a motor of this vintage at those kind of revs.
I tended to cruise along motorways at 85 to 95mph, which was smooth and stable. Just by whacking open the throttle I had a useful burst of acceleration to 125mph in hand when one of the cagers got ideas above his station in life (which was to eat my exhaust fumes). The suspension was much stiffer than stock but the riding position so natural that I wasn't upset by either bumps or 150 mile jaunts in one sitting. A sure sign of a good riding position on a naked bike is the ability to take a couple of hours at 90mph; BMW defined such ergonomics in the seventies and the past owner copied them on to my bike.
Only when the tyres, after about 8000 miles, wore down to 2mm was there any hint of instability or undue sensitivity to road surface markings. The bike was heavy going through fast bends but steering accuracy was profoundly good on worn tyres there was both a vagueness and a jumpiness when the wheels were assaulted by bumps. It was just frightening enough to make sure that I never ran the big Suzuki on bald tyres.
Such was the feeling of oneness that I had few worries about pushing hard in the wet, turning in some of the best times that I’ve ever managed during our atrocious winter. A good set of waterproofs kept the worst of the weather at bay, although on sub-zero days I did sometimes wish for the protection of a large fairing. The bad weather ruined the finish in short order, even if the mudguards were larger than stock and the grime from the chain was contained within its enclosure. There were too many nooks and crannies for the dirt to hide.
The O-ring chain and full enclosure were good news, extending chain life from a paltry 5-6000 miles stock to around 15000 miles on a good quality O-ring chain. It only needed oiling at every 1500 mile service interval, which was usually just an oil change as I soon gave up checking the valves (they never changed their settings). Oil changes are critical on this era of engine, especially if a lot of town riding is done as the oil emulsifies.
Weak spots in the GS engine are, the already mentioned, electrics and the clutch, (rattling at tickover is quite normal). The electrics can be checked by test riding with all the lights on to see if the battery drains, looking over the rectifier to see if it’s been modded and pulling out the fuses to see if they are the correct rating (I found one bike with a charred nail instead of a fuse). The clutch is fairly obvious as it'll usually slip or chatter furiously.
Around 40000 miles a new camchain and/or tensioner might be necessary, but some bikes go to 60000 miles without incident? The crankshaft and gear primary drive are difficult to break even when abused and neglected. Infrequent oil changes or failing to jet the carbs for non-standard exhausts (the OE silencers only last for three years) can lead to top end demise.
The chassis is mostly affected by rot which can reach epidemic proportions over the years. A lapful of fuel from a rusted out petrol tank is not uncommon. If it's made out of steel it'll eventually rust through. That’s not a big disaster as most long term owners will want to customize their machines to a minor extent. As well as a respray | even went to the trouble of taking the engine cases off and having them bead-blasted. Made all the difference to the overall appearance.
The GS750's a bit infamous for caliper rot but | found that if they were rebuilt every time | changed the pads (9000 miles front, 11000 miles rear) then | had no seizures whilst on the road. The brakes were a bit remote in action but after the first few howling wheels | soon learnt to adapt.
My bike has now done 58000 miles with just a set of clutch plates and camchain tensioner fitted to the engine. I’ve ridden through ridiculous weather, commuted day in and day out, cruised for hundreds of miles in a day and had many a memorable jaunt down the back roads without finding the machine’s limits.
I've come off twice. The first time due to diesel on the road, at about 20mph. Minor damage to the bike that was saved by the engine bars and panniers. No damage to myself. The second accident was when a car shot out of nowhere, making me jam on all the brakes and slide off. The bike went into the side of the car, tyres first, and I went into the gutter, head first.
Again, minimal damage to bike and rider but a creased car that looked like a write-off. The cager wouldn't believe it was entirely his fault, not even when he was booked for dangerous driving and was led off swearing and brandishing his fist at me. Some people!
Any way you want to look at it, the GS comes across as a very tough machine that’s highly competent in almost all circumstances. I know that some adrenaline junkies will find it somewhat boring but I don’t think Suzuki were aiming the bike at them, although it’s still possible to buy a big bore kit and hot cams. Surprisingly, there are still quite a large number of bikes floating around that are in good condition despite being over fifteen years old. Surely, a testament to the inherent quality of the engineering and to the loyalty that the GS750 inspires in its owner.
Paul Baker