The red GPZ500S was cheap, 750 notes. The clock read 76000
miles. The cosmetics were crap - alloy rot, rust, and leaking suspension
and engine. The motor rattled into life with its off-beat note, spewed out
a bit of oil and then settled down to a 1200rpm tickover. I swung a leg
over the elderly beast. The bike fitted me to perfection, felt immediately
at home with the GPZ. Until the thing leapt forwards a foot with engagement
of first gear. Clutch drag from cold! The box had engaged as if the selector's
dogs were well shagged.
First ride. Weak, imprecise front end. Bouncing rear. Horrible
gearchange, loads of chain lash. The single front disc was still strong.
The engine growled fiercely at 7000 revs and shot the bike forwards. Not
hard enough to do my vision in but I smiled nevertheless. The 375lb machine
was easy enough to point where I wanted despite the shot suspension and
infamous sixteen inch front wheel.
I offered 650 notes, the bike was mine for 700. Riding
home, I played with the throttle, struggled with the gearbox and fought
with the handlebars. I won out, arrived back at HQ with a big grin if shaking
hands... the vertical twin motor has its pistons moving up and down alternatively
and a gear driven balancer, but wear had got to the components, vibes pouring
out, especially between 3000 and 6000 revs.
Nothing I couldn't get used to, having spent a pleasant
couple of summers with a GPz305 - you want to experience vibration, mate,
ride a 305 with shot big-ends! The GPZ500 could still put 125mph on the
clock without any real effort on the part of the motor. The chassis was
a different ballgame, the suspension being completely worn out! The tyres
were marginal Avon radials. The bike didn't so much hold a line as hop from
bump to bump, white-line to white-line, like a high speed rabbit looking
for somewhere to die. Fighting the bars tended to blow up the weave into
a wobble, much better to gently caress the grips and go with the flow, as
long as the flow was going where you wanted to go...
The first time I got into serious trouble, I'd over-cooked
my line into a bend where some old git was meandering along on the other
side of the road where the GPZ wanted to hustle. The suspension had already
bottomed out and gone into a self destructive frenzy due to the complete
absence of damping. Applying the brakes turned the bike into a rigid framed
horror that bounced to the left and then the right, gave every impression
that it wanted to throw me out of the seat. Holding on to the bastard and
leaning off to one side persuaded it that it wouldn't be a good idea to
smash into the oncoming vehicle.
My survival was accompanied by a sudden need to dump the
contents of my bowels, a rank smell of fear coursing off my body. After
five minutes recovery, I kicked the tyres, shook the forks and patted the
tank. The latter gave with frightening ease, no doubt rusting away from
the inside out. The rest of the ride home was done at a much more moderate
velocity, the lack of revs showing up various engine rattles, massive driveline
lash and a disturbing need to fall into corners.
The long list of bits needed added up to more than the
cost of the bike, so the obvious hunt through various breakers was undertaken.
My requests for a newish front end were greeted with hilarity - GPZ's notorious
for losing it from the front, mashing the weak forks. Nothing for it but
to strip the forks down and bung in some new seals and stiffer springs (they
were weak from new!). That cost forty notes, grazed knuckles and general
disillusionment with the build quality of Japanese motorcycles. The caliper's
bleed nipple, for instance, needing to be drilled out and the replacement
Araldited back in (not a good idea - Ed!). A used shock off some huge old
bruiser of a four was persuaded on, new swinging arm and headstock bearings
further reducing the chassis slack.
Even more dosh was spent on a replacement petrol tank,
sprockets and chain, newish saddle, a battery that didn't have white plates
and new cables all round. All that added up to a wonderful firmness, good
directional stability and a useful flickability. The driveline still whirled
around in a frenzy below 3000rpm in any gear taller than fourth and the
motor still put out an excess of vibration, but I could now ride the bike
between 7000 and 10,000rpm without fear of hitting cars or ending up in
a ditch - those revs held all the power and allowed the engine to smooth
out to an acceptable degree, though I would never describe it as electric.
The major problem over the next 4000 miles was the finish.
I spent a whole week polishing the beast up to a nice shine, cleaning off
the rust and patching it up, and also getting all the crud off the alloy.
All it took was a couple of days of rain to have it going back to nature
pronto. The silencers were evidently original, a major achievement given
the mileage. The price paid were large areas of rust, little baffling left
and the need to hustle along in a tall gear whilst in town; otherwise the
rozzers went absolutely berserk. I reckoned that the silencers had about
a month's life left in them!
A Motad 2-1 was hammered on, not new as they are too expensive.
This f..ked up the carburation something rotten until I took out the ancient
air-filter for cleaning - they can be done by blowing air through them,
so at least that was cheap enough. There was still a bit of a stutter between
4000 and 5000rpm but it was easy enough to howl through with a bit of thought
and effort.
The only way to deal with the rotting chassis parts was
by replacement. Even the plastic was going off, cracking around the mounting
holes and sort of fading away to a horrible shade of white or red. The engine
finish was intractable, could be cleaned up but the white fur came back
rapidly. Rust seeped from under the silver frame paint without actually
making it fall off! It cleaned up but kept coming back. Skimpy mudguards
didn't help. Having no faith in the state of the engine, I wasn't inclined
to rip the bike down to its component parts, blast 'em and powder coat.
After 4000 miles I realised that something was seriously
amiss with the engine. Starting was difficult, power was misery and vibes
increased to worrying levels. I decided it needed an oil and spark plug
change. The former was a piece of cake, the latter a disaster. Appallingly,
the plugs need the petrol tank removed and are located deeply in the cylinder
head. I was pissed at all the effort needed to replaced them and went completely
ape when I stripped the right-hand plug thread! Only an excessive amount
of willpower stopped me using my largest hammer on the engine!
An interesting horror story was revealed when I started
stripping the motor down. For a start, the engine bolts were seized in solidly,
needed an excess of hammer work to get them out. Every thread in the engine
seemed seized in as well. When I finally got the cylinder head cover off,
the camshaft lobes and rockers were shot to hell and back again. By the
time I'd removed the head, I wasn't that surprised to see scored bores.
Worse still, the small-ends were loose! Given the awful state of the gearbox
there wasn't much point trying to rebuild it.
A newer engine was installed, much smoother and more powerful
yet. The chassis was trying hard to return to dust, so a quick polish and
trade-in deal at the local importer got me some wilder wheels.
H.R.