Mountfield Petrol Chainsaw Primer Bulb Instruction Manual

Product Overview

This genuine Mountfield primer bulb (Part Number 118804231/0) is a critical component designed to facilitate the starting process of your petrol chainsaw by drawing fuel into the carburetor. It is manufactured to high standards to ensure reliable performance and a precise fit as a replacement for the original part.

Image of the Mountfield primer bulb, a small, clear, dome-shaped component with a black base and two connecting tubes.

Key Features

• Genuine Mountfield replacement part.
• Manufactured to exacting standards for durability.
• Exact fit for original equipment.
• Ensures efficient fuel priming for easier engine starts.

Compatibility

This primer bulb is compatible with the following Mountfield petrol chainsaw models:

• MC 3112 (2017, 2018)
• MC 3616 (2012)
• MC 3720 (2016, 2017, 2018, 2015 - 16")
• MC 3814 (2017)
• MC 4216 (2017)
• MC 438 (2012, 2013, 2014, 2015)
• MC 4616 (2017)
• MC 5218 (2017)
• MC 640 (2012, 2013, 2014, 2015)

Please verify your chainsaw model and year against this list to ensure proper fitment.

Installation Guide

Safety Precautions

• Always ensure the chainsaw engine is off and cool before beginning any maintenance or installation.
• Disconnect the spark plug wire to prevent accidental starting.
• Wear appropriate personal protective equipment, including safety glasses and gloves.
• Work in a well-ventilated area and be mindful of fuel spills.

Tools Required

• Screwdriver (appropriate size for housing screws)
• Pliers (for hose clamps, if applicable)
• Clean rags

Installation Steps

1. Prepare the Chainsaw: Ensure the chainsaw is turned off, cool, and the spark plug wire is disconnected. Place it on a stable, flat surface.
2. Locate the Primer Bulb: Identify the existing primer bulb, typically located on the carburetor or engine housing.
3. Access the Bulb: You may need to remove a cover or air filter housing to gain access to the primer bulb and its fuel lines.
4. Disconnect Fuel Lines: Carefully note the routing of the fuel lines connected to the old primer bulb. There are usually two lines: an inlet from the fuel tank and an outlet to the carburetor. Use pliers if necessary to loosen any clamps, then gently pull the lines off. Be prepared for minor fuel leakage.
5. Remove Old Bulb: Depending on the design, the old primer bulb may be pressed into a housing or secured with a clip. Carefully pry it out or unclip it.
6. Install New Bulb: Insert the new Mountfield primer bulb into the housing, ensuring it seats firmly and correctly.
7. Reconnect Fuel Lines: Reattach the fuel lines to the new primer bulb in the correct orientation. The longer line typically goes to the fuel tank (inlet), and the shorter line to the carburetor (outlet). Ensure connections are secure to prevent leaks.
8. Reassemble: Replace any covers or air filter housings that were removed.
9. Check for Leaks: After reassembly, add a small amount of fuel to the tank if it's empty. Observe for any fuel leaks around the new primer bulb connections.

Operation

The primer bulb's function is to manually draw fuel from the tank into the carburetor, ensuring a rich fuel mixture for easier starting, especially after the chainsaw has been sitting for a while or run out of fuel.

Priming the Engine

1. Ensure the fuel tank has sufficient fuel.
2. Locate the primer bulb.
3. Press the primer bulb repeatedly (typically 5-10 times) until you see fuel flowing through the clear lines or the bulb fills with fuel. Some bulbs will become firm when primed.
4. Once primed, proceed with your chainsaw's standard starting procedure.

Maintenance

Regular inspection of the primer bulb can help prevent starting issues.

• Visual Inspection: Periodically check the primer bulb for cracks, hardening, or discoloration. A brittle or cloudy bulb may indicate it needs replacement.
• Fuel Line Check: Inspect the fuel lines connected to the primer bulb for any signs of cracking, leaks, or loose connections.
• Functionality Test: If the engine is hard to start, check if the primer bulb draws fuel effectively when pressed. If it doesn't fill with fuel or feels spongy without resistance, it may be faulty.
• Cleaning: Keep the area around the primer bulb clean from dirt and debris to prevent contamination of the fuel system.

Troubleshooting

Specifications

Warranty Information

Specific warranty information for this replacement part is not provided in the product details. Please refer to the original manufacturer's warranty policy for genuine Mountfield parts or contact your point of purchase for details regarding their return or replacement policy.

Customer Support

For further assistance, technical support, or inquiries regarding this primer bulb, please contact the seller or the official Mountfield customer service. When contacting support, please have your chainsaw model number and the primer bulb part number (118804231/0) available.