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1) BREAK YOUR ENGINE IN FAST AND IT'LL ALWAYS BE FAST
The
grain of truth here is that if the piston rings are never seated
against the cylinder walls by proper break-in, they won't seal and
the engine will never develop full power. On the other hand, how
fast should break-in be? Do you take out your new. zero-miles bike
up the interstate? No. A normal break-in, as described in the
maker's manual, and performed with understanding, is all that's
needed.
No matter how fine the surfaces produced in manufacturing on
cylinder walls and crankpins, they are like the Alps in comparison
with the much finer profiles that proper break-in will create.
Break-in is the final machining operation. The oil films that will
support moving parts in operation may be as thin as 1.5 microns
(.00006 inch), so to avoid piercing these' films, the Alps of
manufacturing must be scrubbed down to even lower height by the
process we call break-in.
A normal break-in calls for a period (usually 500 to 1000 miles) of
controlled operation in which the engine is never steadily, heavily
loaded. You would not, for example, climb long hills on full
throttle and low rpm. The idea of break-in is to impose short
periods of various loads, separated by recovery periods. While the
Alps are at work, knocking each other down, wear particles and heat
are produced. The recovery periods allow the heat to dissipate, and
allow the particles to flush out from between surfaces and be swept
away to the oil filter. Once break-in is complete, engine oil and
filter are changed. That's it.
2) ALL ENGINES NEED MORE COOLING
This
one is history. Remember the guys with all the scoops and ducts, the
black paint, and the extra, welded-on fins? Back when most engines
were air-cooled, there wasn't enough cooling to allow continuous
full-power operation without burning
up, so savvy tuners over jetted,_ using the extra fuel's heat of
evaporation as an internal engine coolant, and to limit combustion
flame temperature. Jetting to the chemically correct mixture (at
which every molecule of oxygen in the air charge i1-reacted with
hydrogen or carbon from the fuel, leaving no extra fuel unburned)
gives maximum power and maximum heat release, hut on that jetting,
poorly cooled engines would run hard for a couple of laps, then
cook. That heat would cause the intake air to expand and lose
density, thereby causing power to fall off. Over jetting, by
limiting this heat, allowed engines to lose less power. This is why.
even today, air-cooled 500 MX engines sound so rough; they are over
jetted to the point of misfiring when cold-so they'll keep more of
their power when they're hot. More cooling would help these engines.
Modern liquid-cooled engines can be overcooled to the point where
they lose power-simply because too much heat is being absorbed by
cool metal surfaces in the combustion chamber, leaving too little
heat in the combustion gases to generate pressure to act on the
piston. Tuners learn by experiment what coolant temperature gives
best performance. This is why you'll often see race bikes with their
radiators partially taped-over when going out for practice on a cold
morning. Conversely, you'll also notice that Yoshimura has decided
its Suzuki 750 Superbikes need more cooling than they have, and have
provided two extra oil radiators.
3) GOTTA SCREAM YOUR ENGINE ALL THE TIME TO GET REAL
PERFORMANCE.
The fragment of truth here is that the rpm of the torque and
horsepower peaks is usually higher than it's appropriate to use in
most street or highway situations; you use less power than you have.
Yes, a racer keeps his tach in the region of peak torque and
horsepower to get the most from his engine. But some street riders
(and even a few racers) assume that if a little is good, too much
ought to be just enough. You hear them winding their poor, suffering
engines far into the red zone, above the torque and horsepower
peaks, above the good performance-just to hear the noise. And they
are going slower than the rider who knows where the peaks are.
To make power at higher rpm, the engine must be given the ability to
breathe up there-with longer cam timings, refined porting, perhaps
bigger carbs, and suitable exhaust system.
4) BUILD IT REAL LOOSE. THERE'S BIG POWER IN BIG CLEARANCES.
It's true that racing engines often have larger clearances than
street engines, but it's wrong to jump to the conclusion that this
is done to cut friction,
A racing engine is on full throttle more than a street engine, so
its piston temperature is higher and its pistons expand more.
Therefore they need some extra clearance- Street engines must be
quiet, which calls for low-expansion cast pistons run at close
clearance. The extra stress put to a race motor often calls for the
extra strength of forged pistons, but forging alloys expand more
with heat than do casting alloys, and so require more clearance. At
operating temperature, racing pistons fit as closely as street
pistons: they must in order to present their rings squarely and
stably to the cylinder walls. A loose, rattling fit is an invitation
to loss of ring seal. Also, pistons are cooled by close contact with
the cylinder walls; a loose fit means hotter-running pistons.
5) THE FEWER THE CYLINDERS, THE GREATER THE TORQUE.
This one derives partly from Number 6 above, and partly from the
different riding qualities of different engines. A big single seems
to have impressive torque when you ride it, but on the dyno, a twin
or four of the same displacement almost always has as much or more.
It's just that a big single feels so torquey. The feeling comes from
the flywheel mass, and from the ability of a slow-turning engine to
produce thrust without rpm. A single needs big flywheels to idle,
and in rough going, those heavy flywheels may carry it through where
a twin or four might bog. A single usually has moderate to small
valve sizes, so its torque is given at low rpm. That being so, it
also usually has very conservative cam timings-timings that give
full torque at some wonderfully low, putt-putt speed like 3500 rpm.
On a four, snapping open the grip at 3500 produces nothing but a
cloud of fuel fog from the carbs and a sickly drone from the
exhaust.
Sensibly designed engines take advantage of their natural strong
points. A multicylinder engine has a lot of potential valve area,
and so is usually designed in such a way that its torque and power
are given at higher rpm. A single, with far less cylinder-head real
estate in which to set valves, is therefore (usually, but not
always) designed to deliver its torque at the low speeds that small
valves favor.
6) MAN. I CUT MY FLYWHEELS PAPER-THIN, SO NOW MY ENGINE REVS UP
FANTASTIC.
It's true that during acceleration, extra power is consumed in
speeding up moving parts. Between two otherwise identical bikes, the
one with light flywheels will usually have some edge in
acceleration, but not in top speed This process can be taken too
far. When Honda raced its RC166 six-cylinder 250 back in the
mid-1960s,
and again when it tried to race its NR500 oval-piston four-stroke in
the early 1980s, crank mass was reduced practically to nothing. The
result? These engines were tricky to ride because they could Stall
between downshifts, or indeed any time the clutch was pulled.
Recently some enterprising engine fanatics decided to build a V-twin
out of car-engine components, but they left out the flywheel.
Result? Their engine had such violent variations in crank
speed-owing to lack of rotating inertia to smooth it out-that it
often stalled on the dyno, or tossed its valves. Although it had a
potential for nearly 100 horsepower, it developed only a third of
that in tests.
Any piston engine needs a flywheel capable of storing enough energy
at idle speed to compress the charge on the next cycle without
stalling. If you plan to run at higher rpm, you can get away with
less flywheel, because energy storage in a flywheel increases with
rpm. But you can go too far-as Honda once did.
7) BOOST POWER WITH SECRET ANTI-FRICTION COATINGS.
Internal combustion engines have a mechanical efficiency of 75
to 85 percent. This means that 15 to 25 percent of the power
delivered against the pistons by combustion pressure is wasted as
internal friction. Engines last a long time before they are worn
out, so it's clear that most of the time, moving parts don't touch
each other in metal-to-metal fashion, but are separated by a more or
less complete oil film. This being so, most of that 15 to 25 percent
friction loss occurs in the oil films supporting the parts-between
pistons and cylinders, between shafts and bearings, etc. If oil
viscosity is reduced a lot to cut this loss, the oil films fail and
scuffing occurs.
Therefore, what do the makers of mystery coatings and lubes expect
us to believe? Oil viscosity-the source of most engine friction-is
what makes lubrication work. Without viscosity (and the friction
that goes with it) seizure would be instant. This simple fact rules
out the most extreme coating and additive claims-the ones that say
things like, "Boosts engine power by 15 percent!"
Some small part of total friction is caused by actual
surface-to-surface contact at areas of peak pressure, such as cam
nose-to-tappet, or between piston rings and cylinder wall near TDC
where piston velocity is near zero and combustion gas pressure is
maximum. In these areas, surface-to-surface contact occurs but,
because wear is very slow, it is clearly quite minimal.
All right, then. Shift our attention to surface-to-surface
contact-that small fraction of total engine friction. Here, surface
coatings can work. That is why they are included in the additive
packages of nearly all engine oils-in the form of metallic compounds
that adhere to metal surfaces. When surface contact occurs, it is
this metallic compound that scuffs and shears-not the parent metal
under it. The coating heals itself, but the oil additive is
eventually used up and must be replaced.
What are we left with? Coatings are unlikely to provide measurable
power gains. Honda, in recent research with very carefully applied
(no spray cans!) coatings of tried-and-true solid lubricants, found
power gains, if any, must be less than one half of one per cent.
Where is the value, if any? If there is a value, it would have to be
during break-in, when local pressures and temperatures are very
high, and surface-to-surface contact is frequent. If parts break-in
to smooth, polished surfaces, they will be able to carry heavier
loads later on, and certain coatings may help in this. If you feel
like making an experiment out of your brand-new engine, then go for
it- but only after a careful reading of the terms of your warranty.
8) RECIPROCATING WEIGHT EATS POWER.
Time and again you will hear this-that parts moving back and
forth consume power. It's true that the crankshaft has to accelerate
the piston from a dead stop at top and bottom center, up to peak
piston speed at midstroke, but the crankshaft gets that power back
in the act of slowing the piston back down again. Energy is neither
created nor destroyed-it is simply exchanged between the crank and
piston. In this case, the crank slows slightly as it accelerates a
piston (or valve, etc.) up to maximum speed, and it speeds up again
slightly as it gets the energy back again at the other end of the
stroke.
Of course, the weight of the moving parts creates inertial
resistance to these accelerations and decelerations. A half-pound
piston, accelerating at 3000 Gs, imposes a load of 1500 pounds on
the wristpin, rod, and main bearings, and that in turn slightly
increases the frictional drag on the engine. Most of an engine's
friction drag occurs between piston, rings, and cylinder. The
rest-some 10 to 15 percent-occurs in the rotating bearings on crank,
rods, and valve drive. Since only about 15 percent of the engine's
power is eaten up by all sources of friction, and only 10 to 15
percent of that is bearing friction, we have perhaps 15 percent of
15 percent equals 2 percent of engine power consumed in the crank
bearings. If we cut piston and con-rod weight by 10 percent (not so
easy to do) we may gain 10 percent of 2 percent, or one-fifth of one
percent-too small to worry about.
Then why do designers and tuners work hard to cut reciprocating
parts weight? Bearings last longer under lighter loads, or can be
resized smaller for slight economy gains. Con-rod bearings are among
the hardest-worked parts in an engine, so lighter pistons and con
rods mean longer rod-bearing life. In the valve train, lighter parts
will continue to follow the cam profile up to higher rpm than will
heavier ones. Light valves, rockers, pushrods, or tappets are
created to prevent valve float-not to reduce friction. Finally,
fast-moving parts in the engine
store energy, just as a flywheel does. When the engine accelerates,
it takes some power to increase the average velocity of con rods and
pistons. The less those parts weigh, the less power is consumed in
speeding them up.
9)THERE'S A SECRET CARBURETOR THAT'LL DOUBLE YOUR MILEAGE, BUT THE
OIL COMPANIES HAVE SUPPRESSED IT.
First, there's the element of wishful thinking. For the people
who prefer Uri Geller to the insights of thermodynamics, it's always
entertaining to believe that some backyard inventor has created
perpetual motion. And, after all the other mischief that the Bad
Guys have fomented, it's easy to believe They have put the lid on
this miracle carburetor.
However, the truth is mundane. A carburetor sprays a fog of droplets
of various sizes into the intake. The smaller ones manage to
vaporize before compression and ignition, but some percentage of
bigger drops are still little liquid worlds when combustion starts,
and remain that way, evaporating furiously, all through the cycle,
finally being ejected, blackened and only partly burned, out the
exhaust. Also, gasoline is a mixture of chemical species, some of
which are not very volatile- especially nowadays. The volatile
fraction evaporates easily, but the heavy stuff can separate out as
it whizzes through the manifold, remaining liquid. This heavy stuff
and the big droplets are therefore at least partly wasted. In an
old, inefficient machine, in need of a tune-up, this fuel might be
as much as 15 to 20 percent of the total burned.
Anyone who has worked around laboratory research engines has seen
the evaporator carburetors normally used on them; they are heated by
steam to ensure that no part of the fuel remains unvaporized. This
type of carb is used because it eliminates the unwanted variable of
fuel vaporization.
The secret, mileage-increasing carburetors operate in exactly the
same way- by heating the intake charge to obtain full vaporization.
However, most auto engines already heat their intake manifolds to
some degree with radiator water and exhaust-gas heat-to obtain good
drivability during warm-up. Some new bikes and snowmobiles now have
carbs heated by engine cooling water, to ensure fuel vaporization.
Heating the intake air more than this may indeed result in a small
gain in mileage-but it is in direct proportion to how many of those
oversized fuel droplets your carburetors are putting out. Heating
the intake air a lot-to the point of complete fuel vaporization-also
expands the intake air enough to considerably reduce power. When
Mystery Carb Corp. publishes mileage gains, it is always on big,
old, unsophisticated V8 engines- never on modern, fuel-injected
equipment. Those older engines, with blob-spray carburetors whose
jets and metering rods are worn to a huge oversize, may indeed give
much better mileage with a Mystery Carb.
Will Mystery Carb double your mileage? (Will my mileage quadruple if
I use two Mystery Carbs?) No, sadly, it can't.
10) REAL RACING DESIGNS ALWAYS HAVE ROLLING-ELEMENT BEARINGS ON
EVERYTHING.
At one time, plain bearings had not yet been developed to their
present excellence, and building a race engine with them was an
invitation to bearing troubles. Mercedes-Benz designed all its
racing engines in the thirties and fifties with complex, extremely
expensive built-up Hirth cranks-all so they could use reliable,
proven rolling-element bearings on mains and rods. Plain bearings
were something cheap for economy designs- but, not suitable for high
performance. People who grew up reading about all this came to
believe that ball and roller bearings are the only thing for high
speed. Rollers are "cool." I believed it for years.
Meanwhile, automotive shell-type plain bearings were rapidly being
developed to high reliability and, indeed, had long existed in
aircraft engines in a form able to carry extreme loads. Once such
bearings could be mass-produced, and the technology for designing
with them was understood, rolling bearings and the complexities they
involved were quietly put in the attic. At high speeds and loads,
there is little advantage to rolling bearings over plain ones in
terms of friction loss, and plain bearings are actually capable of
carrying heavier loads and greater misalignments. The one-piece
cranks used with plain bearings are far, far stronger and
more reliable than are the multi piece type used with rollers.
You may now ask, "Then why are auto makers turning back to roller
cams, and why are they again investigating rolling bearings for
cranks and rods?" Their reasons lie in fuel economy, and in the way
cars are used. Cars spend most of their time at very small throttle
openings, often running only partly warmed-up in commuter service.
Under these conditions, rolling-element bearings have an advantage
in lower friction.
11) STACK ON ALL THE COMPRESSION YOU POSSIBLY CAN--THAT'S THE WAY TO
MAKE POWER.
Compression ratio is a major variable in making power. The
higher the ratio, the further you are expanding the burned gases,
and the greater the energy you are extracting from them.
Unfortunately, there are limits to this process:
(a) As you go higher, the gains diminish. It's a bigger step from a
3:1 ratio to a 4:1, than from 12:1 up to 13:1.
(b) Raising compression makes your fuel more likely to knock, rather
than burn normally. Heavy knock destroys engines, and must be
avoided.
(c) When you raise compression, you make the combustion space
smaller. To
be
efficient, combustion must be rapid, so designers try to create
rapid motion in the air/fuel charge by cleverly directing the intake
streams, using squish bands, and so on. Very high compression leaves
little room for air motion, so it can actually slow combustion down.
As compression rises above 12.5:1 in four-valve engines, there is
usually not enough time for a complete burn at high rpm. This means
that high compression-really high, like 14:1-only produces a gain at
lower and middle rpm. This is precisely why drag racers use these
high ratios-because they need to make their engines "turn the tire"
off the start line.
When these extreme ratios are used in road racing, the engine has
good punch down low, and fades out higher up. This is why they use
lower ratios than do dragsters.
The rule of thumb about compression? There is no easy rule.
Different engines need different ratios in different applications.
More is not always better. Experimentation is the only final answer.
In general, the smaller the bore, the more tolerant the engine will
be of compression-because the flame-travel distance is smaller and
combustion is faster. Long-stroke engines, because they have more
room above their pistons at a given compression ratio, tend to have
more efficient combustion. In general, the higher the rpm, the less
likely detonation becomes- because there is less time in which the
conditions necessary for detonation can develop-and the higher the
C.R. that can safely be used.
12) HOG OUT THOSE PORTS, THROW IN BIG VALVES.
The intent of this idea is correct. If you want more power,
you'll have to flow more air/fuel mixture, and that may mean that
ports and valves will have to be increased in flow capacity. But is
that the same thing as "hogging 'em out"? It is not!
First of all, it is not airflow alone that fills engine cylinders;
there must be velocity as well. This is because a fast-moving intake
stream can continue to "coast" into the cylinder long after bottom
center-giving a slight, free supercharge. This is the ram effect.
Pushing velocity too high with tiny ports runs into losses from air
friction. Making velocity too low by making the ports too big just
kills the ram effect and loses power.
Second, many engine designs today already have port sizes that are
too big for best power. Making them bigger yet- even with the
careful use of an airflow bench-may just kill your midrange without
boosting the top end much.
Finally, those who jab a die-grinder into a port intending to make
it "real big" will likely offend the Gods of Airflow, doing more
harm than good. Many are those who, blowing up their "good" ported
head, were forced to fall back on a stock spare, and then went
faster.
13)RACE ENGINES ALWAYS RUN HEAVY OIL. IF I PUT SOW IN MY STREET
BIKE, IT OUGHT TO RUN LIKE STINK.
As in so many other myths, this one dates to the air-cooled
days-in particular to when iron Harley race motors ran with
900-degree cylinder head temperature.
Oil's primary job in the engine is to keep the moving parts from
touching each other. It does this by virtue of its viscosity-its
fluid friction. Oil is made viscous enough that it will not be
squeezed from between the parts even under the highest loads. Any
more viscosity than this simply adds drag to the engine.
Oil viscosity falls with increasing temperature. Therefore, engines
with ineffective cooling systems thin their oil out badly. To
prevent this viscosity loss from reaching the point where moving
parts break through the thinned oil film and seize, the engine is
given more viscous oil to begin with-maybe even that SOW "gear
grease" I just mentioned above. Those hot-running iron Harleys had
to start with extra-heavy oil so that, at operating temperature,
they would get the same bearing and piston protection that other,
cooler-running engines can get from straight 30 oil. Therefore,
unless your engine runs as stove-hot as those old-timers did,
putting extra-heavy oil into it buys you nothing but extra internal
friction-from shearing all that resisting viscosity.
14)THE MORE FUEL YOU BURN, THE MORE POWER YOU MAKE- SO RUN IT AS
RICH AS IT'LL GO. SPECIAL-RACING FUELS SO HOT IT'LL BURN YOUR ENGINE
RIGHT OUT.
I grew up near an airbase where I was always hearing about the
guy who bribed the sergeant to pump him some aviation gas. On that
sweet-smelling stuff his car or bike ran great-no knock, and pulled
up hills without overheating. The sergeant tells him he can get him
jet fuel, too. Assuming that since jet engines are more modern and
powerful than piston engines, their fuel must also be something
extra-special, our man does the deal. He wonders a little, as he
pours the stuff in on top of the av-gas already in his tank, why it
smells so much like kerosene. Without knowing it, he has changed the
antiknock rating of his fuel from 100-plus, down to somewhere south
of 50. Off he goes, his engine now knocking like an old taxi. After
a few miles of sustained, heavy detonation, his engine is reduced to
smoking junk. Man, that jet fuel is hot stuff- ran so good, burnt my
motor right out.
In fact, aviation gasoline of the blue, green, or purple persuasions
is excellent stuff in terms of anti-knock properties, and is used as
the basis for many racing gasolines. Aviation gas contains
essentially the same energy per pound as does street gas, and won't
make more power than street gas unless you increase compression
ratio to take advantage of its superior knock resistance. Its big
drawback in non-aviation engines is its low volatility, which may
keep it from vaporizing to form a good mixture in an unheated intake
system. Turbine (jet) fuel is in fact severely pro-knock, and is
similar to kerosene. Turbines don't need anti-knock fuel; piston
engines most certainly do.
People who say this don't understand that there is a chemically
correct mixture, and that power drops if you go either richer or
leaner than this mixture. Yet there is a reason why so many have
believed it; back in the air-cooled days, engines needed extra
richness for internal cooling, because air-over-fins was so
ineffective in getting rid of heat. Therefore, with those engines,
you enriched the mixture almost to the misfire point, and ran that.
The extra fuel prevented the engine from heating up as much as it
otherwise would have, and it made more power in a long event. Now,
with the coming of liquid cooling, this extra richness is no longer
necessary, and tuners jet as close as they can to the chemically
correct mixture. That's where the power is, if you can get rid of
the heat.
15) CRANK IN A BIG HANDFUL OF SPARK LEAD AND GO FOR BROKE.
Spark lead (how far in degrees before top center the ignition
spark occurs) is another of the variables that can lead to
detonation. The more lead you crank in, the longer you are holding
hot burning mixture at high pressure, and the likelier it is to
knock. On the other hand, you'd like to have combustion reach peak
pressure at the optimum time so that maximum power is given to the
piston. The trouble comes when the best tuning for performance is
too advanced for the fuel. As you dial in more lead, and the power
is coming up nicely, you run into knock.
In drag racing, where the engine runs for only a few seconds, the
combustion chamber is relatively cool off the line. A drag racer can
run a lot of lead and get away with it for this reason. He may need
it, too, for at the compression ratios drag racers use, combustion
chambers are tight and slow-burning. Extra compression and spark
lead work for them because they don't run long enough for the excess
to cause trouble.
Cranking in more lead remains popular on the street because people
figure that if it works at the strip, it has to be the hot ticket
down the avenue. Yet time and again these timing advances are dyno-tested
on stock engines and fail to show any gain. Why are they made? For
drag engines with high compression and combustion chambers so tight
that flame speed is slowed down in making its way around all the
valve cutouts and bumps and lumps, it's useful. In a street bike,
with its much more open chamber, extra advance is just not necessary
or desirable.
According to legend. Old Man Yoshimura used to crank in about 45
degrees on his air-cooled, 1025cc Superbikes and literally go for
broke. After a few laps of torrid,.glorious action up front, the
engine would fry. Later, like everyone else, he learned to make
faster-burning combustion chambers with lower compression ratios
that would go fast all day on 10 or 15 degrees less lead. In fact,
among experienced tuners, being able to run a very minimum of spark
lead is regarded as a sign of an efficient combustion chamber. A
two-valve engine running 30 to 32 degrees would be regarded as
efficient, as would a four-valve burning in fewer than 30 degrees.
16) BORE THAT MODEL TO THE MAX--YOU CAN'T BEAT CUBIC INCHES.
It's true that it's hard for a good small engine to beat a good
big engine, other things being equal. On the other hand, the limit
of power is set by how fast you can turn the engine and still fill
and empty its cylinders. Cylinder filling is limited by valve and
port sizes, so a 10 percent displacement increase usually doesn't
bring a 10 percent power increase; valves that were the right size
for the smaller engine are too small for the big one. The result is
that the oversized engine now gives peak torque at lower speed than
did the original. The torque is increased because combustion
pressure is now pressing down on bigger pistons. Horsepower may have
increased, but not very much; with torque
being up, and rpm being down, these tv factors cancel somewhat.
Often, oversized motors are pleasant to ride because of their
generous torque, and because they need not be buzzed to get thrust.
17) THEM RACING PLUGS, RACING JETS, RACING T-SHIRTS.
The lure of the exotic is felt by us all, bi some few have to
try silly stuff like cold heat-range racing plugs in street
engine-or big jets without the other changes the make them necessary
in modified engines. Street bikes use warm heat-rang plugs to
prevent fouling at the moderate engine heat loads they produce. Race
engines push much more heat through their components, and spark
plugs must be of cooler-running design to avoid having; overheated
electrodes act as glowing, sources of premature ignition. Putting;
cold racing plugs in a street engine is an invitation to fouling.
How many times have I heard, at shops, a customer asking the
mechanic to "Throw in a set of racin' jets." Modified engines, with
longer cam timings an< free-flow exhaust systems, often need jet
ting up to compensate for a sluggish in take process at low rpm.
Some persons knowing only that large jets are somehow associated
with powerful motors, want t( screw big holes into their stockers.
The result is blubbery throttle response, black plugs, and reduced
power at all speeds. All this is not to say that no street bike;
ever need rejetting. In these times o EPA-mandated carburetion,
street bike; often come with fairly severe lean spots and to correct
this, jet-and-needle kits an offered by the aftermarket. Sometime'
these kits work well, but their good performance is the result of
repeated dyne and road tests. You can't get there b) simply making
everything richer. It would be very nice if swagger and dash could
be substituted for all this fuss) testing and fiddling. (Throw in a
set o them racin' jets! Crank in more lead!) Unfortunately, our
swaggering makes little impression on reality. For the
swagger-and-dash people I can only recommend harmless
modifications-like generic racing team T-shirts, jackets, hats, and
stickers. They go well with myth.
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