Yamaha XMAX YP125R - Service manual > Throttle body

Removing the throttle body (YP125R)

Removing the throttle body (YP125R)

Removing the throttle body (YP250R)

Removing the throttle body (YP250R)

Removing the fuel hose

1. Extract the fuel in the fuel tank through the fuel tank filler hole with a pump.

2. Remove:

• Fuel hose connector cover "1"

3. Disconnect:

• Fuel hose "2"

NOTICE

• Be sure to disconnect the fuel hose by hand. Do not forcefully disconnect the hose with tools.
• Although the fuel has been removed from the fuel tank, be careful when removing the fuel hose, since there may be fuel remaining in it.
• Do not disconnect the fuel hose from the fuel hose connector. Disconnect the connector from the fuel pump.

TIP

Before removing the hose, place a few rags in the area under where it will be removed.

Checking the fuel injector

1. Check:

• Fuel injector

Damage → Replace.

Checking the throttle body

1. Check:

• Throttle body

Cracks/damage → Replace the throttle body.

2. Check:

• Fuel passages

Obstructions → Clean.

a. Wash the throttle body in a petroleum-based solvent.

Do not use any caustic carburetor cleaning solution.

b. Blow out all of the passages with compressed air.

3. Check: (YP250R only)

• Piston valve

Damage/scratches/wear → Replace.

• Piston valve diaphragm

Cracks/tears → Replace.

4. Check: (YP250R only)

• Vacuum chamber cover
• Piston valve spring

Cracks/damage → Replace.

5. Check: (YP250R only)

• Piston valve movement

Insert the piston valve into the throttle body and move it up and down.

Tightness → Replace the piston valve.

Installing the intake manifold (YP125R)

1. Install:

• Intake manifold joint "1"
• Intake manifold "2"

TIP

Make sure that the projection "a" on the intake manifold joint is facing down.

Installing the intake manifold (YP250R)

1. Install:

• Intake manifold joint "1"

TIP

Make sure that the recess "a" in the intake manifold joint is aligned with the thermostat cover.

Installing the fuel hose

1. Install:

• Fuel hose
• Fuel hose connector cover

NOTICE

When installing the fuel hose, make sure that it is securely connected, and that the fuel hose connector cover is in the correct position, otherwise the fuel hose will not be properly installed.

TIP

• Wipe up any fuel remaining in the recess "a" in the fuel pump with a dry rag "1".
• After installing the fuel hose connector cover "2", make sure that it is installed securely.

Installing the throttle body

1. Install:

Throttle body

TIP

Align the projection "a" on the throttle body with the slot "b" in the throttle body joint.

A. YP125R

B. YP250R

Checking the throttle position sensor

1. Check:

• Throttle position sensor

Checking the isc (idle speed control) unit

1. Check:

• ISC (idle speed control) unit

See also: