Yamaha YZF-R125 Service Manual: Checking the decompression system

Yamaha YZF-R125 Service Manual / Engine / Cylinder head / Checking the decompression system

1. Check:

  • Decompression system

a. Check the decompression system with the camshaft sprocket and the decompression cam installed to the camshaft.

b. Check that the decompression lever "1" moves smoothly.

c. Without operating the decompression lever, check that the decompression cam "2" projects from the camshaft (exhaust cam) as shown in the illustration "A".

d. Move the decompression lever "1" in the direction of the arrow shown and check that the decompression cam does not project from the camshaft (exhaust cam) as shown in the illustration "B".

Checking the decompression system


Checking the decompression system


    Checking the timing chain tensioner
    1. Check: Timing chain tensioner Cracks/damage/rough movement Replace. a. Lightly press the timing chain tensioner rod into the timing chain tensioner housing by hand. NOTE: While pressing the ...

    Installing the cylinder head
    1. Install: Cylinder head NOTE: Pass the timing chain through the timing chain cavity. 2. Tighten: Cylinder head bolts "1" Cylinder head bolts "2" NOTE: Lubricate the cylinder ...

    Other materials:

    Ignition circuit cut-off system
    The ignition circuit cut-off system (comprising the sidestand switch, clutch switch and neutral switch) has the following functions. It prevents starting when the transmission is in gear and the sidestand is up, but the clutch lever is not pulled. It prevents starting when the t ...

    Installing the swingarm
    1. Lubricate: Bearings Spacers Dust covers Pivot shaft 2. Install: Bearings "1" 2. Swingarm A. Left side B. Right side 3. Install: Swingarm adjusting collar "1" Swingarm "2" Pivot shaft Pivot shaft nut "3" a. Install, and then fully turn in the swingarm adju ...

    Circuit diagram
    4. Main fuse 5. Main switch 9. Battery 14.Neutral switch 25.ECU (engine control unit) 31.Fuel sender 34.Rear brake light switch 35.Front brake light switch 37.Tail/brake light 38.Rear right turn signal light 39.Rear left turn signal light 40.Front right turn signal light 41.Front lef ...

    2026 Copyright www.yam-r125.net |