Saturday, 21 January 2017

Suzuki GT750


Like many other GT750 owners, I was a little shocked and upset by the harsh comments of the editor on this fine machine. My only consolation was that I hadn't paid a silly price for mine.

I was fortunate in paying only £100 for the bike. True, it didn't actually run, but the previous owner had assured me that it was working OK when he'd become fed up with bikes and stuck the Suzi at the back of his garage. As the owner had agreed to deliver the bike to my doorstep I couldn't really complain over the price.

I took out the three plugs, looking down the holes and spinning the back wheel with the bike in gear, showed that the pistons hadn't seized up and it made some promising noises. I changed the engine and gearbox oil, fitted some new plugs and a new battery.

There were no lights, horn or sparks. I traced this fault to a corroded earth strap. Much to my excitement, the lights and horn worked, but still no sparks. I traced the ignition wires from the manual, tried all the spade connectors until I achieved a nice fat blue spark.

As with most two strokes the compression is low, so it's easy to leap up and down on the kickstart. The watercooled two stroke triple doesn't have much compression, so it's not too difficult. The engine made some inspiring noises but after twenty kicks it still hadn't come alive. Then I noticed that two of the spark plug leads looked like they were on the wrong way around.

I swapped them over, and it sounded like it was starting to fire on one cylinder. Out with the plugs, wire brush them clean and heat them over the gas stove. Back in the engine before they get cold, and the thing started second kick.

Blipping the throttle to keep the engine from cutting out, resulted in clouds of blue smoke. This cleared after a minute or two and the engine settled down to a regular tick over at about twelve hundred. It was on with the gloves and the helmet for a quick thrash around the block. The tyres had gone hard and slipped if I leaned over and the disc brakes didn't work.

By the time I'd purchased two new tyres, a chain and two sets of disc pads, I'd almost spent another hundred quid. These didn't exactly transform the bike, but they made it relatively safe to venture out into the Kent back lanes. The pattern pads took half an hour to work in the wet (so did the stock ones... Ed) and the rear shocks and swinging arm were worn out. Over bumpy roads this wasn't too much fun and when I got the bike up to an indicated 110mph it disgraced Itself by going into a tank slapper.

Unlike the editor and various friends, my response was blind panic and shoving on the brakes. The effect is hard to describe, the bike seemed to buckle and squirm underneath me, before I knew it I was on the other side of the road heading straight towards the oncoming traffic. Luckily (?), it continued leftwards, hitting a patch of gravel on the side of the road. By this time, speed was down to about sixty; by the time I actually fell off it was down to thirty.

The bike went back across the road while I rolled along some convenient grass. Much to my surprise the Suzi missed the cars and landed with only a few dents. I escaped with a bruised thigh and ego. Careful examination of the swinging arm revealed a huge amount of free play. The plastic bushes were actually cracked and the spindle scored. I found a spindle in the breakers and spent an afternoon fitting new shims and bushes. I also fitted a secondhand set of Koni shocks. I can take a hint...

With the rear end sorted, I next had to start worrying over the front forks which would dive, buckle and twist whenever I braked really hard. I tried some heavier oil and this helped a little. I didn't want the hassle of stripping the forks to fit heavier springs, so I settled for a fork brace. This took another afternoon to fit because it tended to jam the forks, but I eventually made it work OK.

These modifications still didn't make the Suzi perfect, but it was now quite predictable. My next stage was to try to reduce the mass by replacing as much metal as possible with plastic. New mudguards, seat base (home made out of GRP) and a three into one exhaust system helped to reduce the stock 520lbs to under 500lbs.

That exhaust system was a bundle of trouble. It only cost £25 from a breaker, but it ruined the carburation. All low speed power (and there's normally quite a lot) disappeared. I had a two thousand rev powerband when the bike went like shit off a shovel. After trying different jets I had to give up and revert to the standard three into four system, which worked well despite numerous rust holes and partially blown baffles.

Fuel consumption was a little frightening, it gave 30mpg however I rode and as I often did 500 miles or so in a week this was a very expensive habit. Despite riding quite hard, not bothering with the ignition timing (no strobe...) and restricting maintenance to filling up the oil tank, the engine has given no trouble in eight thousand miles of ownership (it had thirty grand on the clock when I became the owner). The previous owner reckons he hasn't stripped the engine, so 38000 miles for a two stroke isn't bad going and I feel there's plenty of life left.

If I don't change the spark plugs every three thousand miles it becomes difficult to start and the clutch has started to slip at very high speeds. Because it's only cost me £250 so far, I can ride the thing without worrying over wrecking it. If it does blow up on me in a big way, I'll probably just dump the thing in a ditch and start hunting around for another cheapo Jap hack.

I think the engine's classic material but the rest of the bike isn't much cop. Even with the modified suspension the bike still wallows although I haven't had another tank slapper yet - and in the country I've been burned off by 250 Super Dreams. But there's power to cruise at 100mph, although, again, the riding position is the usual sit up and beg crap.

I've had the footrests and centre stand sparking along the tarmac. Getting too confident I once managed to dig the centre stand into the road, lifting the back wheel off the road - it took my stomach about a week to recover from that one. I've had some rides that were so enjoyable that I'd have liked to do them over again straight away if I could have afforded the petrol. And I've scared myself silly a couple of times and sworn my head off at the bike.

I've seen some silly prices demanded for GT750s, even over a grand. But really, they aren't classics - just cheap hacks.

Brian Reading

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