Yamaha YZF-R125 Service Manual: Checking the camshaft sprocket and timing chain guide

Yamaha YZF-R125 Service Manual / Engine / Cylinder head / Checking the camshaft sprocket and timing chain guide

1. Check:

  • Camshaft sprocket More than 1/4 tooth wear "a" Replace
    the camshaft sprocket, timing chain and crankshaft as a set.

Checking the camshaft sprocket and timing chain guide


a. 1/4 tooth

b. Correct

1. Timing chain roller

2. Camshaft sprocket

2. Check:

Timing chain guide (exhaust side) Damage/wear Replace.


    Checking the cylinder head
    1. Eliminate: Combustion chamber carbon deposits (with a rounded scraper) NOTE: Do not use a sharp instrument to avoid damaging or scratching: Spark plug bore threads Valve seats ...

    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 ...

    Other materials:

    Checking the speed sensor
    1. Check: Speed sensor output voltage Out of specification → Replace. a. Connect the pocket tester (DC 20 V) to the speed sensor coupler (wire harness end) as shown. Positive tester probe gray "1" Negative tester probe gray/black "2" b. Set the main switch to "ON". c. ...

    Assembling the crankcase
    1. Thoroughly clean all the gasket mating surfaces and crankcase mating surfaces. 2. Apply: Sealant (onto the crankcase mating surfaces) NOTE: Do not allow any sealant to come into contact with the oil gallery. 3. Install: Right crankcase NOTE: Turn the shift drum segment ...

    Disassembling the front wheel
    1. Remove: Oil seal Wheel bearings a. Clean the surface of the front wheel hub. b. Remove the oil seal "1" with a flat-head screwdriver. NOTE: To prevent damaging the wheel, place a rag "2" between the screwdriver and the wheel surface. c. Remove the wheel bearings "3" with a ge ...

    2021 Copyright www.yam-r125.net |