BOMBARDIER 1996 Ski-doo MX Z440 Handbook page 245

You can easily check your gearing selection by marking your drive clutch with a black marker with
straight lines from bottom to top on the belt surfaces of the clutch. Go out and ride your sled under
your normal conditions and stop to see how far the belt has rubbed the marker off the clutch
surfaces. If it has shifted the belt all the way to the top, you may be able to pull one or two more
teeth on the top sprocket. Experiment!
If it is down about 1/2 in or more from the top, you could consider trying a one tooth smaller top
gear depending upon your type of racing.
The best combination of gearing for speed and acceleration you can achieve is far more important
than shifting the belt "all the way to the top" of the clutches.
The following formula can be used to calculate the theoretical top speed of your Ski-Doo. The
formula assumes the transmission is shifted out to its top gear ratio. Make sure you use the correct
track pitch and transmission ratio for your machine.
Square shaft clutch top ratio = 1
TRA clutch top ratio = .83
Pitch of internal drive track= 2.52 in
Pitch of external drive track= 1.966 in
Number of teeth on external drive sprocket= 11
Number of teeth on internal drive sprocket= 9
top speed = engine RPM x
in
MPH
clutch ratio
Example : 1995 Formula Z - gearing 25/44 peak power at 7800 RPM
7800
X ~ X
.83 44
For quick reference, use the gear ratio charts provided.
A little known fact that can seriously impair a racer's performance is the misconception that the
factory stated peak horsepower RPM or the peak power point you find on a dyno is the correct
figure to "clutch" your race sled to.
Generally, this is not the case. The figures that are printed by the factory are determined on a
dynamometer in clinical test conditions.
teeth, top sprocket
teeth, bottom sprocket
(2.52 91
X X ~ = 115
12 5280
Section 05 TRANSMISSION SYSTEM
{pitch of track x No. of teeth on drive sprocket) x 60
x
12
MPH
05-41