Fireblade Problems & Cures
The following information is
courtesy of Performance Bikes (October 2003)
They took a shagged, 20k mileage, Urban Tiger to John Hensman
at the The Honda Institute. This is Honda's vehicle preparation
and training centre near Heathrow for diagnosis and repair.
The details have been left as printed, for you to read into
the symptoms and cures as you wish, in order to try and fix
any problems with your Blade.
Notchy feel under braking
Fireblades like wheelies, but head race bearings don’t.
Positioned top and bottom of the headstock to provide slick
steering movement, the head race bearings receive a sharp
jolt of pressure every time the front wheels slams back to
First sign that they’re unhappy will be a notch, or
slight forward motion of the bars under braking. The Blade
uses caged ball bearings, which, funnily enough, are half
encased in a plastic cage and sit in a ‘race’,
which in turn nestles in the headstock. Should you ignore
the notch, the bearings will move against the top and bottom
edges of the race and eat away at the surface until a pit
appears. By then the notch will be so annoying that you’ll
have to replace the bearings and race just to preserve your
Both the bearings and race are pre-greased, but this dries
in time increasing the chance of pitting. Re-greasing and
re-tightening – to the correct torque setting, of course,
is often enough to cure the problem.
Blade requires a special tool to tighten the bearings to the
John's difficulty rating:
DIY price (grease, new lock tab): £10
Dealer price (inspect and repack plus labour):
2.5 hours, £70-80
Repacking or fitting new head race bearings isn't massively
difficult in itself, but the FireBlade requires a specialist
tool to re-torque the bearings. You could try your luck with
a screwdriver and hammer, but over or under tightening the
locking nut will leave the bearings and race open to damage.
Either way, it's best to remove the fairing, forks and front
wheel first, to gain better access to the head stock. Undoing
the Blade's head stock bolt revealed rust on the top of the
steering head column. You'll need the special four-pinned
socket to remove the head stock nut Although the Blade's bearings
were dry, the notching sensation under braking hadn't damaged
the race, so a liberal covering will see them right for a
few miles yet.
Dropping the bottom yoke revealed the lower bearings, which
were also recoated and reseated in their race. Don't use copper
grease, though, it'll eat into both the bearings and race.
If bearings are beyond a quick regrease, replace them in pairs.
The Blade's require 25 Newton metres of preload to perform
to their optimum. Locking nuts only need to be finger tight
- any more and they increase the bearing's preload. Move the
bars side to side several times to seat the components. With
the forks and wheel back in situs, John uses a spring balance
to double check the bearing preload. The bars require 1.5kg
of force to move full lock - in other words, it's spot on.
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Spongy front end
Often overlooked in favour of fancy shocks
and swingarms, forks have a knock-on effect on other areas
of a bike’s performance. Like braking. There’s
no point in splashing out on a trick brake set-up if your
forks hit their bump stops every time you brush the lever.
An internal inspection and oil change is an effective and
inexpensive way to suss and improve your front end’s
condition and it’s performance.
Like engine oil, fork oil deteriorates and picks up contaminates
with age and use. Also like engine lube, fork oil condition
is critical to the performance of the surrounding components.
The oil acts as a damper within the forks and is worked very
hard. Particles from bronze and phosphor bushes within the
forks will contaminate the oil over time, although a degeneration
is less of a problem than with engine oil because condensation
can’t form inside a sealed chamber.
Old oil will lessen the damping capabilities, leading to spongy
feel and/or wallowing. To check if it’s past its best,
wind the damping up to maximum. If there’s little increase
in resistance the oil’s had it.
use of Ribena is not recommended.
John's difficulty rating:
DIY price (fork oil x2 bottles): £23.50
Dealer price (parts plus labour): 2.5 hours,
Because it's out of sight, fork oil is all
too often out of mind. But why spend all that money on decent
rubber and sharp brakes if your suspension's not up to the
job? There's no inspection schedule on the Blade's fork oil,
but John advises an oil change at 16,000 miles. With 20,500
on the clock, our CBR looks long overdue.
John's tip for supporting the front end: place the back end
on a paddock stand, then jack up the front end from under
the exhaust's 4-1 section, using a piece of wood to cushion
the pipes. Once the front wheel's out undo the yoke bolts
to release the forks. Measure how much the forks protrude
above the top yoke first however, so you know where to put
them back, then wind off the preload, to take pressure off
The Blade's forks are good, except for oil seals that have
been seated with a screwdriver. Once the fork top's off, the
spring's removed and the old oil is drained and pumped from
its inner chamber. John's suspicion that the Blade was on
original oil proves correct as it emerges looking like gravy.
Add the required amount of fresh oil, from a clean container
of course, before pumping the damper rod for several strokes
to bleed the damping chamber of any air. Resistance will build
up as you remove the air. Then reassemble.
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Symptoms: Woolly and spluttery throttle
response, poor economy
This Fireblade’s got more peaks and troughs in its
carburetion than a Derbyshire pig farm. At low rpm it splutters
away to itself before finally clearing it’s throat
and producing something remotely resembling forward motion.
At high rpm it can’t decide how much fuel to feed
the cylinders, hesitation every 1000 revs to make up it’s
mind. In short, it’s a chore to ride.
And it’s little wonder, considering the state of the
airfilter. Stained almost black in places, the once red
filament seems to have been doing its level best to prevent
any air getting into the motor. With the fuel/air mix unable
to find a happy medium it makes the Blade very hard to settle
before a turn – not that you’re want to with
those tyres – or hold at a constant throttle.
The fuel filter is equally clogged with bilge and well past
its use-by date. If a motor is to give its best it requires
a constant regulated flow of clean air and fuel –
something this bike hasn’t enjoyed for some time.
of a vacuum gauge for balancing, is easier with the carbs
John's difficulty rating: 2-3/5
DIY price (air filter): £26.75
Dealer price (parts plus labour): 2 hours,
Early Blades' plastic fuel taps are often forgotten about
in the frenzy to get to the bike's guts, and snap off as
the tank is lifted free. Whipping It off first with a Phillips
screwdriver saves a lot of swearing.
With the tank and airbox cover off, we soon uncover a major
player in the 900's piss-poor fuelling. The airfilter looks
as though it's spent most of its life on a garage floor,
such is its filthy condition. Its mesh backing plate, designed
to stop things like stones, insects and rodents from entering
the motor has broken away from the filter. And the filter
itself is an unwashable viscous jobbie, so its only future
vocation will be filling a bin - as will the fuel filter
which also proves to be long past its best.
Attaching a vacuum gauge to the carbs - in order to inspect
and correct the fuelling - sounds easy enough, but the connecting
points are located on the inlet tracts underneath the carb
bodies. John reckons it's easier to remove the carbs to
attach the vacuum pipes.
Some of the lumpy throttle response is down to slightly
worn needles, which, if left in place long enough, wear
the emulsifying tubes oval, thereby allowing fuel past the
needles and richening the mixture. Inlet manifold rubbers
can perish, leading to air leaks, but the Blade's are still
serviceable. The ovel1!ll set-up of the CBR's carbs wasn't
bad, but a slight adjustment to pot one's butterfly screw
crispened things up considerably.
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4. SPARK PLUGS
Symptoms: poor fuel consumption and
The scary thing is, this Blade’s plugs look as if they’ve
never been changed. All credit to NGK for manufacturing a
consumable that lasts that long, but after seven years in
the block they’re hardly an aid to the performance or
sweet running of this bike.
The efficiency of the plugs has been compromised over time
and their ability to produce a fat, healthy spark is reduced
by a major build-up of soot at their business ends –
especially on those from cylinders three and four. To surmise:
the better the spark, the better the ignition, the better
over tighten the sparkplaugs - they can snap off in the heads
John's difficulty rating: 2-3/5
DIY price (plugs): £33.37
Dealer price (parts plus labour): £60-70
Sounds like child's play, but can actual_ be an hour's work.
For starters you've got to remove the fairing, but even
then It's not that easy to gain access to the plugs from
underneath the frame rails. John recommends going in through
the top, removing the tank, airbox and inner frame heat
shield to gain access.
Like most bikes, you'll need a deep plug spanner to gain
a purchase on the Blade's plugs. If you're whipping them
out to check for a spark, don't rest them on the magnesium
head or you'll run the risk of blowing a hole straight though
it. Although there's a tool in the CBR's toolkit that looks
like a plug-gap vernier gauge - if It's still there at all-
ft is in fact for setting up the caliper/disc distance.
Plug gap on Blades is recommended at O.7mm, whereas the
caliper/disc clearance is 0.9mm.
Plugs are an excellent way of sussing a rnotor's state of
health. The Blade's were sooted, particularly on two and
three, which suggests ft's running slightly rich. They'd
also been in there for an age and were well past their best,
so swapping them for new 'uns will increase ignition efficiency
and economy. Plugs should also be retightened to the recommended
torque setting, because an over tightened plug could snap
on subsequent extraction.
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5. ENGINE OIL/FLUIDS
Symptoms: Motor feels rough and noisy.
Engine needs oil. Its importance cannot be underestimated.
As well as lubricating moving parts, oil also helps cool the
internals. Dirty oil loses its ability to lubricate and cool
the motor, causing premature wear and stress on components
– including the clutch and gearbox. Clutch slip can
be an early sign of poor oil condition. Milky residue on the
dipstick or sight window indicates a build up of condensation.
The oil in this Blade is black, old and has a metallic sheen.
A freshly oiled motor will run smoother, quieter and more
Old coolant is unlikely to directly affect performance, but
it can certainly lead to a hefty bill if left unchecked. An
incorrect level or mix of distilled water and antifreeze (50/50
mix is best), or no antifreeze at all, could encourage electrolysis
in the cooling system – which eats away at metal components.
Insufficient coolant can cause a motor to run too hot, knocking
the edge off performance and also leading to possible pinking
and detonation. And that’s expensive.
engine colling requires a functioning radiator, so take a
wire brush to the front.
John's difficulty rating: 1/5
DIY price (fuel filter, oil filter, oil,
coolant x3 bottles): £57.13
Dealer price (parts plus labour): 1 hour,
You can tell a lot about a bike from little things, like washers.
The sump plug washer on this Blade, which should be replaced
every time it's removed (at 10p each there's no excuse not
to), is twisted and chewed. A warped washer could, if you're
unlucky, click the sump and they're a fair bit more than a
Treating the CBR to fresh Castrol semi-synthetic (John reckons
quality semis are so good there's little need for fully-synth)
will quieten the motor and make it smoother, as well as afford
its internals a greater degree of protection under load.
There really is no excuse for not regularly replacing an engine's
oil because It's so easy to do. John recommends emptying the
sump when the motor's warm, as the lube flows more freely,
and filling the new filter with oil before screwing ft in
place, taking care to clean its mounting point first to avoid
tearing the filter's seal. Filling the filter ensures instant
oil pressure when the motor is fired. Engine oil level is
best checked with the bike upright and off its stand.
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Spongy action with a lack of bite, feel and power.
It’s fair to say that brakes are rather important on
a 160mph motorcycle, not that you’d know it by riding
this Blade. It may have braided hoses all round, but its stoppers
are wooden, lifeless and downright dangerous. A tug on the
front lever achieves little. Then, as the lever gets intimate
with the bar, there’s a jolting sensation and a weak
attempt at deceleration – a classic sign that the pads
Both front pads are nearly down to their backing plates and
the inside front left pads down to the metal, gouging out
a groove in the disc. Left to do it’s worst, this metal
to metal contact will over-heat and warp the disc. Luckily
the damage is minimal and both discs are still serviceable
– there’s 4mm of meat left; Honda’s minimum
recommended limit is 3.5mm.
the correctly filled reservoirs clean fluid, with the previous
John's difficulty rating: 4/5
DIY price (pads, x4 front, x2 rear plus fluid):
Dealer price (parts plus labour @ £25-35
per hour): 1 hour, £115-125
Overhauling brakes is a two-stage job; pads and fluid. Start
by loosening off the pad retaining screw - top middle of caliper.
Then remove the caliper from the fork leg. Unclip the dust
seal to expose the top of the pads, take out the retaining
screw and remove the pads.
The CBR's calipers were caked in brake dust and road gunk.
Left uncleaned, this grime could overcome the outer dust seals
and invite corrosion. An old toothbrush and brake cleaner
spray had the pistons gleaming in no time - the spray moistens
gunk, so you don't breathe it in. An abrasive brush may scratch
the piston's surface, making them easy targets for corrosion.
Once the caliper is clean, release the bleed nipple slightly
and push the pistons back with your finger and thumb. Rub
copper grease on the back and side edges of the pads, before
replacing them in the caliper. The pad retaining screw only
needs to be nipped up. Honda recommends changing the caliper
bolts every time they're disturbed, because they're a stressed
part. Use a non-permanent Loctite when tightening them back
at the correct torque setting.
Time for new fluid. Honda mechanics use a brilliant device
for bleeding brakes, called a mitivac - without it you have
to pump the lever. Top up the master cylinder with fluid as
required and you'll have air-free brake lines in no time.
Finally, clean off the discs with a soft rag and brake cleaning
spray to remove any greasy hoof prints.
Heat build up from shot pads can damage dust and pressure
seals inside the calliper, as well as overwork the fluid.
The fluid in this bike’s system is little better than
muddy water. A low level in the master cylinder has allowed
condensation to form in the air gap, contaminating the fluid.
Old fluid picks up debris from inside the lines, leading to
discolouration and further drop in performance.
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Symptoms: Reluctance to turn in heavy steering.
Tyres are the most critical components on any bike and they
do much more than just provide grip. They transfer power and
braking force to the tarmac and all surface changes back to
the suspension, as well as using their inherent flexibility
as extra shock absorption, so it’s easy to see why tyre
wear/type and condition have such an impact on handling and
Both boots on this Blade have seen better days, but the rear
is by far the worst. IT bears the brunt of the workload, transferring
power to the road, so the middle third of it’s circumference
is bald. This change in profile leaves lips either side of
the centre section, so the tyre has to roll up onto the lip
and then down the natural curvature of the tyre in order to
tip into a bend, creating reluctance to turn, syrupy steering
and s sudden flop into the corner.
The front end is worn in two strips either side of the central
quarter, from heavy braking. As the tyre becomes more worn
and triangulated this adds to the unsettling ‘flop in’
feeling. Worn tyres have a major detrimental effect on handling
and these old boots are definitely scrap.
tyres is an ideal opportunity to check wheel bearings and
John's difficulty rating: 2/5
Pirelli Diablo 130/70 ZR16 front: £125.72 RRP
Pirelli Diablo 180/55 ZR17 rear: £166.85 RRP
DIY price (loose wheels, fitted and balanced):
£10-15 per wheel
Dealer price (ride in, ride out): £15-20
Not many folk possess the equipment to remove, fit and balance
lyres so you're basically left with two options: whip out
the wheels yourself and take them to your local motorcycle
establishment in the back of your Morris ltal, or ride the
bike there and get said shop's highly trained experts to do
all the dirty work For the sake often or 15 quid you might
as well stick your feet up, light a tab and watch an oily
fingered gentleman do it for you.
But before you remove the wheels, check the wheel bearings.
Put the bike on a paddock stand, or get a mate to hold it
upright grab a wheel on both sides of its circumference and
apply pressure in both sideward directions. The wheel should
remain static. If not your bearings need an inspection at
the very least. This Blade's bearings are fine, but the rear
bearing dust seals, which prevent dust and water from entering
and damaging the bearings, were shot Always regrease bearings
and copper grease wheel spindles before reassembly - makes
life easier next time. We chose Pirelli Diablos for the Blade
because of they are stable and grip like limpets. Plus they'll
instantly improve the handling ten-fold.
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