IAME Parilla Norswift 60cc User Manual

19 MAN-071
13 - 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, roller cages, bearings etc.) will be such as to drastically reduce
the life of the engine itself. It is therefore extremely important that the user respects the
operating limits imposed by the manufacturer.
The operating limit for the NORSWIFT engine is 12.500 RPM.
ATTENTION:
Never exceed the above limit. No obligation of IAME exists in case the above limit is
exceed.
In case the user wishes to optimize on the track the sprocket ratio in order to achieve the
best possible performance, without abusing the engine, follow the under shown
recommendations.
The engines are supplied with a 11 teeth sprocket (pitch: 7.775mm), and you can also
use 10 teeth sprocket.
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
10
11
Teeth n° Axle
sprocket
10
11
72
7,20
6,55
83
8,30
7,55
73
7,30
6,64
84
8,40
7,64
74
7,40
6,73
85
8,50
7,73
75
7,50
6,82
86
8,60
7,82
76
7,60
6,91
87
8,70
7,91
77
7,70
7,00
88
8,80
8,00
78
7,80
7,09
89
8,90
8,09
79
7,90
7,18
90
9,00
8,18
80
8,00
7,27
91
9,10
8,27
81
8,10
7,36
92
9,20
8,36
82
8,20
7,45
For the operation limit of 12.500 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 spark plug caps with a resistance of 5KΩ to avoid eventual interferences
between the engine ignition and the tachometer and/or telemetry.
Tab.1

IAME Parilla Norswift 60cc Specifications

General

Brand	IAME
Model	Parilla Norswift 60cc
Category	Engine
Language	English