niu N-GT, Service Manual

Page: 5 / 144

V1.0.0 5
Maintenance Rules
1. Metric tools should be made as available as possible in the maintenance of the scooter. Use of
improper tools may damage the scooter.
2 Clean off the dirt outside parts or assemblies of the chassis or braking system before guard
removal from the scooter or opening for maintenance.
3 Please clean parts and blow them with an air compressor after removal and before measurement
of the wearing value.
4 Rubber parts that have become aged or deteriorated are very easy to be damaged by the solvent
or oil. They should be checked or replaced if necessary before reassembly.
5. Multiple assemblies should be loosened in the sequence from outside to inside and beginning with
small ones.
6. Complex assemblies should be stored in a proper installation sequence for further assembling.
7 Extra attention should be paid to important fitting positions before disassembling. Parts that are no
longer to be used should be replaced before disassembly.
8 The bolt or screw length varies with assemblies and guards. Bolts or screws must be installed at
correct positions. A bolt can be placed into a bolt hole for fitness in case of confusion
9 The oil seal should be installed by lubricant application into the oil seal groove, and should be
checked for smoothness, smoothness and damages before installation.
10 The spherical bearings (on the front wheel-hub or rear wheel motor) should be removed by
holding one or two bearing races (the inner and outer races) with tools. The bearing may be
damaged in removal if the force is applied only to one race (the inner or outer race) and thus must be
replaced.
Important notes
1
．
Please use original parts made by Niu. Use of components that are not in compliance with design
specifications by Niu Company may cause damages to the scooter.
2
．
Maintenance operations can be performed only with metric tools. The metric bolts, nuts and
screws can not be interchanged with British fasteners.
3
．
The replacement with new washers, O rings, split pins and lock shims should be made for
reassembly.
4
．
Bolts or nuts should be tightened by beginning with large-diameter bolts or inward bolts and then
gradually tightening to specified torques diagonally, unless otherwise indicated.
5
．
Clean components that have been removed with the detergent solution. All the sliding faces
should be lubricated before assembling.
6
．
Check all components for the proper installation and operating after assembly.
7
．
Remove the dirt and oil stains before measurement. Apply recommended lubricants to sections to
be lubricated during assembly.
8
．
Apply the lubricant to part surfaces to avoid rusting and dust accumulation, if the engine and
transmission systems need to be stored for a long time after disassembling.