IAME MINI SWIFT 60CC - USA User Manual

24
MAN-85 – USA
15- CHOICE OF THE BEST SPROCKET RATIO
The life of an engine depends upon many factors but most of all upon the speed at
which the engine is operated. If an engine is normally operated at speeds higher than
what recommended by the manufacturer, the wears and stress of the various
components (con-rods, cages, bearings etc.) will be such as to drastically reduce the
life of engine itself. It is therefore extremely important that the user respects the
operating limits imposed by the manufacturer.
The operating limit for the 60 MINI SWIFT engine is 14.500 RPM.
ATTENTION:
Never exceed the above limit. No obligation of IAME exists in case the above
limit is exceeded.
In case the user wishes to optimize on the track the sprocket ratio in order to achieve
the best possibile performance, without abusing the engine, follow the under shown
recommendations.
The engines are supplied with a 11 teeth sprocket (pitch 7.775 mm.) Table 1 shows
the various ratios between the sprocket on the axle and the engine sprocket, given the
different axle sprockets.
Sprocket
ratio
Teeth n° - Engine sprocket
Sprocket
ratio
Teeth n° - Engine sprocket
Teeth n°
Axle sprocket
11
Teeth n°
Axle sprocket
11
72
6,55
83
7,55
73
6,64
84
7,64
74
6,73
85
7,73
75
6,82
86
7,82
76
6,91
87
7,91
77
7,00
88
8,00
78
7,09
89
8,09
79
7,18
90
8,18
80
7,27
91
8,27
81
7,36
92
8,36
82
7,45
For the operation limit of 14.500 RPMs, the following table (Tab. 2) has been
prepared.
SUGGESTION
 During the track tests we recommend the use of a tachometer recording the
max obtained engine RPMs.
 Use spark plug caps with a resistance of 5KΩ to avoid interferences
between the engine ignition and the tachometer and/or telemetry.
The following example should clarify the procedure for the optimization of the
sprocket.
Tab.1

IAME MINI SWIFT 60CC - USA Specifications

General

Brand	IAME
Model	MINI SWIFT 60CC - USA
Category	Engine
Language	English