IAME 125 cc LEOPARD TaG engine Assembly Instructions And User's Manual page 31

Tab.1
Sprocket
ratio
Teeth n° -
axle sprocket
72
73
74
75
76
77
78
79
80
81
82
For the operation limit of 15000 RPM the following table (Tab.2) has been prepared.
SUGGESTION:
? ? During the track tests we recommend use of a tachometer recording the
max obtained engine RPM.
? ? Use sparkplug caps with a resistance of 5KO to avoid eventual
interferences between the engine ignition and the tachometer and/or
telemetry.
The following example should clarify the procedure for the optimization of the
sprocket .
Assume to use the engine with Z=10 teeth engine sprocket and that during the
preliminary track tests a Z=72 teeth axle sprocket has been used.
? ? From table 1 with Z=10 as engine sprocket and Z=72 on the axle sprocket, a ratio
of 7.20 is found.
? ? Make a few laps on the track and, let us assume that you read 14.000 max
engine RPM.
? ? From the table 2 to achieve a max RPM of 15000 RPM (operating limit for the
Leopard engine) a sprocket ratio from 7.61 and 7.82 should be used (having
used, during the tests, a sprocket ratio of 7.2 and having achieved 14.000 RPM
max.).
? ? From table.1 , with these values, a sprocket ratio of 10:76 / 10:78 should be used
or, having a Z=11 on the engine sprocket, a ratio 11:85 should be used.
18/10/02 mod. C
Teeth n° - Engine sprocket
10 11
7,20 6,55
7,30 6,64
7,40 6,73
7,50 6,82
7,60 6,91
7,70 7,00
7,80 7,09
7,90 7,18
8,00 7,27
8,10 7,36
8,20 7,45
Sprocket
Teeth n° - Engine sprocket
ratio
Teeth n° -
axle sprocket
83 8,30
84 8,40
85 8,50
86 8,60
87 8,70
88 8,80
89 8,90
90 9,00
91 9,10
92 9,20
29
10 11
7,55
7,64
7,73
7,82
7,91
8,00
8,09
8,18
8,27
8,36
MAN-016 D