Yamaha NEOS 50 YN50 (2002) [87/161] Assembly and adjustment of engine

MOT

ASSEMBLY AND ADJUSTMENT OF ENGINE

4-36

PISTON AND PISTON PIN

1. Apply:

• Engine oil

(in the crankshaft bearing, big end bea-

ring, small end bearing, piston pin, piston

ring grooves and piston skirt areas.)

2. Install:

• Reed valve gasket

• Reed valve 

• Carburettor gasket 

3. Install:

• Small end bearing

• Piston 

• Piston pin 

• Piston circlips 

NOTE:

• The arrow  of the piston should point to

the exhaust side.

• Before installing the piston circlip, cover the

crankcase with a towel or clean cloth so

that the circlip and other materials do not

accidentally fall into the crankcase.

• Always use new piston circlips.

CYLINDER AND CYLINDER HEAD

1. Install:

• Cylinder gasket (Use a new gasket)

2. Check:

• Piston rings

NOTE:

• Ensure that the ends of the rings are

correctly coupled around the centring devi-

ces  on the piston grooves.

• Check that the manufacturers symbols or

numbers printed on the rings are on the

upper side of same.

Carburettor gasket

0.9 m • kg