Selection Of The Aperture Of Carburetor; Size Of Carburetors; Checking And Adjusting Float System - BOMBARDIER 1996 Ski-doo MX Z440 Handbook

SELECTION OF THE APERTURE OF CARBURETOR

One of the prerequisites for improving the output is to use a carburetor with as large an aperture as
possible. However, a large aperture alone does not necessarily improve the output. As shown in
the following illustration, it is true that a large aperture improves the power output in the high
speed range. In the slow speed range, on the other hand, the output drops. The aperture of a
carburetor is determined by various factors. These factors include (1 ) whether the vehicle is
intended for racing, (2) the design of the engine, (3) driving technique of the driver, (4) the driver's
preference, etc. In addition, the maximum output, the maximum torque and the minimum number
of revolutions for stable engine operation must also be taken into account.
44 (1.73 in) (in even numbers for the most part.) The carburetor body
CARBURETOR
Once the aperture of the carburetor is determined, a test to select the proper jet should be made.
The size of the jet is determined by measuring the output in a bench or in a chassis dynamo test.
For racing, it is best to determine the proper size of the jet on the racing track, because the
following points must be taken into account:
a The altitude (atmospheric pressure), temperature and humidity of the race track.
m
The operation of the engine based on the topography of the race track.
b.

CHECKING AND ADJUSTING FLOAT SYSTEM

1. Invert the carburetor and check the alignment between the float arm and the base of the
carburetor. The float arm should be parallel to the base.
OUTPUT
Too large an apert u r e
I
/
/
/
Revolutions Der minute (RPM)
Section 04 ENGINE PREPARATION
of aluminum or zinc.
04-61