Preparation Information; Technical Parameters; Torque Value - Benelli TNT125 Maintenance Manual

Preparation Information

●Function of Cylinder Head:
Cylinder head is used to seal the cylinder and it
forms a combustion chamber with the piston to
withstand the high temperature and high pressure gas.
And it can also complete the intake and exhaust
through the valve mechanism.
●Operation Precautions:
In order to ensure the sealing of cylinder head and
upper box, the cylinder head withstands great bolt
locking force. Pre-tightening force: 12 N·m, locking
force: 19-23 N·m.
Before the inspection and measurement, all parts
shall be cleaned and blown with high-pressure air.

Technical Parameters

Table of standard value and allowable limit of benchmark items
Planeness of cylinder head
Valve
valve guide
Valve spring
Camshaft

Torque Value

Cylinder head screw
Stud bolt of air inlet duct
Stud bolt at exhaust side
Bolt at sprocket cavity
Spark plug
Sprocket bolt
Item
Valve clearance:
Outer diameter of valve stem:
Inner diameter of valve guide:
Clearance between valve stem
and valve guide
Width of valve seat:
Free length
Height of camshaft
19-23N•m
10-12N•m
10-12N•m
10-12N•m
12-15N•m
20-24N•m
Standard
0.05
Inlet 0.08-0.1
Outlet 0.08-0.1
Inlet 4.48-4.49
Outlet 4.465-4.475
Inlet 4.5-4.512
Outlet 4.5-4.512
Inlet 0.01-0.032
Outlet 0.025-0.047
Inlet 1-1.2
Outlet 1-1.2
Inlet 38.5
Outlet 38.5
Inlet 29.5626
Outlet 29.5576
- 208 -
Unit: mm
Use limit
0.05
＿
＿
4.45
4.44
4.55
4.54
0.1
0.1
1.5
1.5
37.7
37.7
29.5426
29.5376