Posted by Witch Doctor on November 21, 1999 at 17:02:44:
In Reply to: Voodoo Mechanics posted by keith on November 21, 1999 at 10:26:55:
Less restrictive exhaust has been shown on a dynamometer
to reduce the rear wheel power on most vehicles that do not
have modifications to the fuel circuitry, the valve system,
combustion-chamber shape, timing, and grade of fuel.
Can be seen on dyno charts in EasyRiders, Motorcycle
Cruiser, Hot Rod, Street Rodder; basically any automotive
or motorcycle publication.
As for fuel injection being superior, a lot depends on
climate, riding style, grade of fuel, and state of tunes
both in carbuerator and engine. A well-tuned carb
on a properly tuned machine (except in cold weather
conditions) is equal to the performance of injection.
Agree with you in principle, not necessarily in practice.
The circuitry in the Savage Mikuni carb is set lean to
meet current US emissions standards. It affects the
entire power band of the machine, not just the cruise
circuitry. These bikes make smoother (more) power when
the white spacer under the jet is removed. Along with
this, several Suzuki mechanics recommend removing the
cap from the air screw and opening the screw 1-1/2 to
3 turns, or to where the idle is smooth (about 1100 rpm)
to maintain proper fuel-air mixture entering the cylinder.
On my bike, the white spacer is still in place. I
increased the air flow via the air screw and the bike
makes a bit more power. I am planning to remove the
white spacer, re-jet both the main and cruise circuits
of the carb, or replace the entire unit with a stock-size
(40 mm) Mikuni flat slide (older series, higher performance
potential) version. The stock carb is fine if you have
a fairly tame riding style. I DON'T.
Suzuki mechanics I have talked to recommend running the
stock carb with larger jets to avoid the "decreased
performance at lower rpm ranges" you mentioned. The largest
carb they recommend is a 42 mm with slightly smaller jets
in all circuits. When you switch carbs to the 42, you also
need to use a performance spark plug and a hotter coil.
Carbuerators are not really "intricate and complicated,"
they just take patience and time to get familiar
with their inner workings. Anyone with regular tools
can work on a carbuerator successfully, whereas with
fuel injection you generally need specialty tools and
possibly a laptop and program for that specific unit in
order to work on the injectors (set, time, fuel map, etc.)
-WD