Bombardier-Rotax FR 125 MAX FR 125 Junior MAX Installation And Operator's Manual page 87

Operating Instructions FR 125 MAX, FR 125 Junior MAX and FR 125 Mini MAX
Motorleistung [kW],
performance of engine [kW]
22
20
18
grosses Beschleunigungspotential
16
big potential of accelleration
14
12
10
8
6
4
2
0
Diagram 2
Power available for acceleration is in the engine speed range between 6000 r.p.m. and 12000
r.p.m. a lot more than between 12000 to 13500 r.p.m. Therefore it is not always the best to use this
high speed range (high top speed on straights) but to use the higher acceleration potential (after
narrow bends) at the lower speed range.
This is just a remark making obvious that the best possible tuning is only possible at exact
knowledge of the race track.
For approximation and optimizing consult Tables 2 and 3.
Note: The values in the tables refer to a maximum speed of 13500 r.p.m. This engine
speed may not be reached because of too high a drive resistance, therefore use the
stated values for approximation only.
The procedure for selection of the transmission ratio for a certain race track will be explained in the
following example.
The kart is fitted with a random transmission ratio (e.g. number of teeth of sprocket on crankshaft =
13 teeth and number of teeth of chain wheel on rear axle = 82 teeth). In Table 2 find the
corresponding transmission ratio 6,31.
With this transmission, drive a few rounds and note the maximum engine speed reached (e.g.
12000 r.p.m.).
Seite/page 87/108
BESCHLEUNIGUNGSPOTENTIAL
POTENTIAL OF ACCELLERATION
Motordrehzahl [1/min.], engine revolutions [rpm]
geringesBeschleunigungspotential
small potential of accelleration
Ausgabe/edition 09.2003