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Yamaha has tweaked the YZ426 to the nth degree since its inception five years ago,
but many riders, raised on two-strokes, find the clutch pull of a big
thumper a chore. The MXA wrecking crew has a quick fix that comes
straight out of the Maico handbook. You'll need access to a welder and a
modicum of mechanical skills to do this mod, but it's nothing that can't
be done in an afternoon. |
Old school: Don't worry, you won't be the first
person to lengthen a clutch arm. This is an old trick that Team Yamaha has
used on their YZ426s. |
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STEP ONE: REMOVE THE ACTUATOR ARM
To start, you will need to
remove Yamaha's clutch actuator arm from the bike. It is a five-step
process.
(1) Take the clutch cable
off (not completely off the bike, but out of both the lever and actuator
arm).
(2) Drain the engine oil
(you don't have to do this, but trust us, it makes everything easier).
(3) Remove the clutch cover
and clutch pressure plate.
(4) Pull the clutch
actuating rod out of the clutch.
(5) Remove the clutch
actuating arm.
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STEP TWO: GO TO THE HARDWARE STORE
With the actuator arm in hand,
head to the store. You will need a piece of steel that is about the same
thickness as the actuator arm. Most hardware stores carry a selection of
steel straps. Cut the steel to approximately the same length and width as
the stock arm (because the stock arm has a bend in it, the steel piece
will need to be a little shorter). |
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STEP THREE: SAW IT IN HALF
Before you cut the stock actuator arm, measure its total length (you
need to know this because you want your modified arm to be exactly 5mm
longer). Now, cut the actuator arm in half. Once it's been cut (we used a
band saw, but a hacksaw works) weld the small piece of metal under one end
of the actuator arm. After the weld has cooled, take the other end of the
actuator arm and clamp it 5mm away from the previously welded part. Before
you weld the pieces together, measure the total length of your new
actuator arm—make sure it is only 5mm longer than it was stock, no longer.
Weld both the top and bottom of the actuator arm for added strength. |
Saw blade: We used a
bandsaw to cut our clutch arm, but it can be done with a hacksaw. |
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ENJOY THE PULL
With the longer actuator arm
installed on your YZ426, the lever pressure will be greatly reduced. The
longer arm increases the leverage, which lessens the amount of hand
pressure required. It might be the difference between arm pump on lap four
and making it to the checkered flag. |
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Reference: This article appeared in a 2002 issue of Motocross Action Magazine.
Unfortunately, I only saved these two pages and they do not indicate which
months issue it is from.
Note: the clutch actuator form the 1998-1999 YZ400F is 5 mm longer than the
standard YZ/WR250F and yz?WR4XXF. This actuator is a direct replacement. Click
here for more details. |
