Jonsered 2095 Workshop Manual

94
Crankshaft and crankcase
8
504 91 40-01
502 50 55-01
Mod. 625/630/670
Mod. 2077/2083
Mod. 2095
505 38 17-09
Mod. 625/630/670
Mod. 2077/2083
Mod. 2095
3 mm
The purpose of the crankshaft in the engine is to
convert the forward and backward movement of
the piston to rotation. In order to do this a stable
construction is required which can withstand high
pressure, torsional and flexural stress, and also
high rotational speeds. The connecting rod is also
exposed to high accelerational and retarding
tensions when it moves between the top and bot-
tom dead centres. This sets special requirements
on the bearings which must withstand rapid load
alternations. In addition the bearing’s roller cage
must withstand high levels of heat and friction.
During service work it is therefore important to
check the roller cage for cracking, wear on the
sides, and discolouring as a result of overheating.
The crankshaft is housed in the crankcase with
heavy-duty ball bearings. In addition to being the
bearing point for the crankshaft, the crankcase also
functions as a pump for fuel/air mixing when this is
”induced” from the carburettor and pressed up in
the cylinder’s combustion chamber. In order not to
interfere with the pump function the crankcase
must be completely tight and there must be no
leakage at the crankshaft or between the crankcase
halves, or between the cylinder and crankcase.
For this reason always replace gaskets and sealing
rings during service work on the crankcase.
Replacement of sealing
ring on magneto side
Mod. 625/630/670
Mod. 2077/2083
Mod. 2095
Screw down the sealing ring extractor as
far as possible in the sealing ring and pull
off the sealing ring.
Lubricate the shaft with engine oil and fit
a new sealing ring.
Replacement of sealing
ring on magneto side
Mod. 625/630/670
Mod. 2077/2083
Mod. 2095
Dismantle all parts on the magneto side
so that the sealing ring becomes access-
ible.
Remove the key for the flywheel by means
of diagonal cutting pliers.
Screw down the sealing ring extractor as
far as possible in the sealing ring and pull
off the sealing ring.
Lubricate the shaft with a few drops of
engine oil and place a new sealing ring in
position with the plate cover turned
outwards.
Press down the sealing ring with a suitable
mandrel to the correct position in the
crankcase.
Fit the other parts in the reverse order to
dismantling.

Jonsered 2095 Specifications

General

Brand	Jonsered
Model	2095
Category	Chainsaw
Language	English