The GNU, a much neglected heap of Suzuki GN400 single on an X plate, was owned by a young lad who lived further down my street. Each morning, at seven o'clock, he would rev the proverbial nuts off it as he came up the road. This alone was not enough to make me want to buy it, but my dog hated the motorcycle and on two occasions escaped from the kennel and bit the rider. It was either the dog or the bike, so I offered the owner £200 and bought it off him.
The intention was to run it until the MOT ran out and then having found out what was wrong with it, strip it down and rebuild it. I had never done this before and a simple single seemed the obvious choice for a first attempt. The MOT had two months to run and I never managed to travel more than three miles without the engine cutting out. Fortunately, it was only two miles to-work, so it was manageable.
When the ticket ran out I parked it up in the garage and left it. A sad and sorry rusting heap in the corner. I had seen more life at a funeral and towards the end the performance (I use that term in its widest sense) had become so poor it was embarrassing. The bike sat in the corner for several months and it was only after some considerable nagging from the wife that I eventually started the rebuild.
I had always thought that it was a bit rough, but only when I started to take it apart did I realise the full extent of its decay. The first thing to come off was the exhaust system. A downpipe that rattled in the cylinder head connected to a home-made baked bean can with a hole in it. This I couldn't salvage and was the first of many things that went on to the replacement list. The seat came off and the reason for the somewhat loose feel was discovered. The base had completely rotted away and a piece of numberplate was inserted - not welded or fixed. This was the next on my list of replacements. The tank was full of dents and bumps but having looked at the price of anything vaguely better, I decided that this could be repaired. The panels, battery box, cone air filter, bars, horrendous tail light fixture and rear guard all followed the seat and exhaust into the bin. Apart from at least twenty seized bolts and ten rounded heads, the rest of the strip was relatively easy for a first timer. I’m sure that some if not most of the bolts hadn't been touched for years.
There followed a period of apathy where the parts just languished in a heap. This was broken by the remonstrations of my wife about the rubbish in the garage. It was either fix it or flog it. As I could not honestly see anyone buying the heap of junk I got to work and started the rebuild. The intention had always been to do the job as cheaply as possible to test my capabilities, and to follow it with a more up-market job on something more powerful at a later date. Therefore, the only criterion was that anything went so long as it didn't cost money.
The wheels were first, having their rusted. spokes sanded and painted with Smoothrite. The rims were salvageable and were just polished. Every other part that was removable was stripped down to bare metal then undercoated and painted black. The fork legs were treated to a new set of seals, fresh oil and the bottoms painted. The first bit of good news was that the chassis bearings were all in good order and well greased. The tank was filled and painted. The 6V electrical system was cleaned, tidied, checked with a multi-meter and fitted back into the chassis.
All the components were treated to a dose of cleaning, polishing, smoothing or whatever seemed appropriate. The alloy parts were painted with heat resistant paint and reassembled. The only real problem was the kickstart. This model has a rep for stripping the teeth on the kickstart and mine was no exception. The only problem was that the previous owner had welded the kickstart back on and I had to repeat the process as the spline was ruined. I had a rolling chassis with an engine in it, looking quite butch in a very lean and mean way.
The next step was to get the seat sorted. My father-in-law managed to use the rusted wreck as a pattern and I scrounged a large piece of kangaroo skin leather to cover it. The exhaust proved a little more difficult but eventually I found an American car breaker who'd bend a piece of tubing for me, using the old one as a pattern. A complete if loud silencer finished off the exhaust. Total cost so far, excluding paint, £45.
A couple of panels, battery shelf and tail unit/guard were knocked up. A new filter and bigger carb jets were next. Together with a host of other minor mods, and with the Suzuki decals missing, the bike looked totally different and very sixties British single. A sudden change of work meant the bike had to be on the road very quickly.
Several unsuccessful attempts to repair the front caliper resulted in £20 being spent on a serviceable item from a nearby breakers. An MOT test was booked, and to my immense pleasure and surprise it passed first time. I did cover up the bald patch on the rear tyre first by making sure it was at the bottom before the bike was tested.
A couple of weeks of use showed that it was now quite reliable if not inspiring in its performance. A new set of shocks (£40) and two new tyres (£70) transformed the handling - at least in the dry if not the wet. So the cost had now risen to £155. I had a good looking but somewhat slow bike that I knew from the ground up. A couple of months commuting and extensive tinkering with the carb failed to add much to the performance and only made it more difficult at tickover.
A new plug cap sorted the tickover and made hot starting acceptable if not easy. Five to ten kicks, instead of twenty and a five minute wait, I ran the bike for several months and got to know it a little better. She was great in a straight line and showed no signs of a weave at all. I’m sure the custom rake of the original bike together with the new flat bars helped this no end. She was not as good in the corners as such a slim and light bike should be, but with a lot of luck and a dose of lunacy she was able to keep up with more modern machines.
Performance was poor for the model even when brand new, the top speed was about 90mph, so when I found that on most flat roads the bike would quite happily put 85 on the clock before the vibes became a nuisance, which equated to about 7000rpm on an engine that red lines at 8000, I was pleased that it held together. When an invitation to the Bull Dog Bash was made by my brother, I was quite confident that the bike would be man enough for the trip. After all, apart from the starting and the fact that it regularly boiled the battery on a long run, she had never failed to get me where I was going. I'd even fitted a new kickstart and shaft.
On arrival at his house the bike was none the worse for wear, used hardly any oil and had returned 60mpg. I was in a worse state than the bike. It most certainly wasn't what could be called a long distance tourer and it took several beers and a good chilli before I was ready for the rest of the journey the next day.
A check Friday morning revealed no major problem from the previous day’s abuse and, loaded up with beer and spirits, I set off to the Bull Dog. I was in good company. There was a very tidy T140, a Honda 1000 monster and an equally neat SR500. The journey went uneventfully and at a good speed, eighty plus. Everyone was surprised how well the little GNU kept up the speed but were not so complimentary about the noise it made. The weekend at the Bash went without a hitch and much against my better judgement I took the bike down the strip on several occasions. She put in some reasonable times and the lad on the SR had to work really hard to beat us. Several times the GNU was in front at the three-quarters stage. lt was only his top end power that got him the result.
By now i had begun to believe that the little engine was indestructible and was thrashing it everywhere. Not a thing to do on a shoestring rebuild with 35000 on the clock. I travelled home at my new cruising speed of 85mph and failed to see the tell-tale signs. I stopped for fuel and it took 35 minutes to start the bike, and then only on the third bump. This puts me in such a good mood that I thrashed her even more on the way home. I didn't go into the red but I hovered around it for quite some time. Ten miles from home a loud and ominous rattle emanated from the top end in the exhaust valve area.
I slowed down to more moderate speeds and got back home. A strip of the top end revealed a written off exhaust cam follower and some marks on the cam itself. The subsequent strip of the head was a nightmare and the drilling out of the alloy bung that retains the cam follower was the most nerve wracking job I have ever done. I succeeded, when the parts were delivered the rebuild was relatively simple. The cam was too expensive to even consider replacing so it just went back in. A couple of minor setbacks, and a training shoe full of hot engine oil later, the bike was back on the road.
I had by this stage learnt to treat it a little more considerately and continued the six miles to and from work, rain-or shine. The quality of my aerosol can spray painting began to show and I have to confess that I was getting bored with it. I neglected the cosmetics, the bike going back to the rat state.
The tyres refused to wear or bed in, no matter how hard I tried to scrub off the surface. In the dry they were just acceptable if care was taken. In the wet they were murderous if anything more than ten degrees of lean was used, doing their utmost to throw me off into or under whatever I was trying to avoid or go round. This was just about controllable in town as everyone else was skating on oily, slippery roads but out of town on normal roads it was a bloody nuisance. Several times I thought my number was up and only survived by a combination of luck, skill and nerve. The bike repaid my neglect with more electrical problems. One trip home during a foggy, cold evening was almost my last journey. At 50mph on a busy dual carriageway every bulb on the bike blew.
How I survived I don’t know and the memory still sends shivers down my spine. An examination of the electrics revealed that every component was working but I had to fit 12V bulbs and keep the revs below 5000 with the lights on, to stop a repeat explosion. The only other option was to run around in the dark with my lights off. A check with my multi-meter showed that the bike was putting out 15 volts at 5000rpm, which would explain a lot of things including my boiled battery. A check of the price of spares showed that new they would cost more than the bike and used they were almost unobtainable and probably no better than the items I was at present using.
The situation was made worse by the fact that my place of employment had now changed and the bike was doing 26 miles a day in commuting chores. I was replacing bulbs with each refill of petrol. The more careful use of the machine returned 65mpg but the open road journey drove me nuts at 65 to 70mph. I was being caught and passed by bloody learners. Only really crazy riding kept me in front of them in town.
By now I was convinced that the thing had to go. It was either that or spend a lot of money on it, which I could not justify. The next hurdle was the MOT. With a great deal of ingenuity and some inspired wiring, I managed to make everything work and the tester passed the bike first time. The fact that the horn only worked with the lights on and the indicators wouldn't work however hard I tried was overcome by taping the lights for the test.
A friend of the previous owner had monitored the rebuild and usage of the bike, and had expressed the wish to have first refusal. He agreed to pay £300 and I felt so guilty that I split the cost of the tax with him. I used it for two weeks' commuting and did a half way passable clean and tidy up of the thing prior to parting with it. My very last trip home from work coincided with some pretty impressive gales.
With the tyres and handling on wet roads, the journey was pretty terrible. On a very slow approach to a roundabout I was blown into the armco barriers and fell off in a heap. Luck was with me, both the bike and myself escaped with very little damage. When the Suzuki left I had mixed feelings. I had rescued it from the grave and rebuilt it for next to nothing. I learnt a lot in the process. It had given reasonable service and even with all its problems had never failed to get me where I was going and then get me back again. The look was different and was appreciated by most with its ration of style.
On the negative side, its performance even when allowed to breathe was poor. Its handling was acceptable in a straight line but diabolical in anything more than a moderate corner. I don’t think I would buy another even if it was a pristine low mileage example, although I have heard quite good reports about the SP/DR variations which are tuned slightly higher and would make a better commuting hack.
If you are short of height and enjoy travelling at 65mph then one might just be your cup of tea. Me, I saved up a few more notes and invested in a good condition, low mileage CB900SS Honda on a V plate. It goes, stops, runs round corners, sounds great, has loads of style and does 43 to the gallon. There’s lots to say about this one but that’s another story.
R. Sainsbury