Engine Tuning; Carburetor Calibration - Bombardier-Rotax FR 125 MAX FR 125 Junior MAX Installation And Operator's Manual

Operating Instructions FR 125 MAX, FR 125 Junior MAX and FR 125 Mini MAX

4. Engine tuning

4.1. Carburetor calibration

The standard carburetor calibration is for an ambient temperature of 25° C / 77° F and 400 m /
1300 ft above sea level. At operation with different temperatures and altitudes, the main jet of the
carburetor has to be changed in accordance with Table 1A respectively 1B, to optimize engine
performance.
Attention: Valid as from engine No. 536 536 (jetting of carburetor R9796).
Main jet
- 5°
+ 5° C
+15° C
+25° C
+35° C
Table 1A
Main jet
+ 23° Fahrenheit
+ 41° Fahrenheit
+ 59° Fahrenheit
+ 77° Fahrenheit
+ 95° Fahrenheit
Table 1B
Attention: A smaller main jet than shown in the table 1A resp. 1B could lead to piston seizure
under the existing conditions.
Attention: Misfiring in the exhaust system between 10.000 and 12000 r.p.m. indicates that the
mixture is too lean (the fuel-air mixture cannot be ignited by the ignition spark).
Note: If under the existing conditions a larger main jet as specified in Table 1 is used, the
engine might only reach a maximum speed of 12000 to 12500 r.p.m. (see diagram 1
resp. 1A).
Note: At engine operation with ambient temperature below 10 °C make sure not to
demand full power before the coolant temperature has reached 45 °C.
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altitude
0 Meters 400 Meters
178
175
172
170
168
altitude
0 Feet 1300 Feet
178
175
172
170
168
altitude altitude
800 Meters
175
172
170
168
165
altitude altitude
2600 Feet
175
172
170
168
165
altitude
1200 Meters
172 170
170 168
168 165
165 162
162 160
altitude
3900 Feet
172 170
170 168
168 165
165 162
162 160
Ausgabe/edition 09.2003