Craftsman Lt1000 Fuel Pump: Step-By-Step Replacement Guide

If your Craftsman LT1000 lawn tractor is having trouble starting, it may be time to replace the fuel pump. This can be done by disconnecting the fuel pump from the carburettor and checking for fuel flow. If there is no fuel flow, you can try cleaning the carburettor and fuel filter. If that doesn't work, you may need to replace the fuel pump. You can find fuel pumps for Craftsman LT1000 online or at small engine dealers. When replacing the fuel pump, make sure to check the fuel lines for any blockages and ensure that the pump is properly connected to the vacuum line.

Check if there's fuel flow

To check if there's fuel flow, disconnect the fuel pump from the carburettor and put it in a cup. Then, turn the engine over to see if you're getting fuel flow. You should see some flow when the engine spins, but not a lot.

If you're not getting any fuel flow, you could try pulling the fuel line from the filter and see if you get any suction on the hose when the engine is cranking. If you don't, the fuel pump diaphragm is likely to be damaged.

The diaphragm in the fuel pump can wear over time, causing small holes to form. This can result in a loss of vacuum, which in turn affects the fuel flow.

Check the fuel pump diaphragm

To check the fuel pump diaphragm of your Craftsman LT1000, you will need to perform a series of tests. The diaphragm is a crucial component of the fuel pump, responsible for pushing the fuel through the pump. Here is a step-by-step guide on how to check it:

Step 1: Understand the Type of Fuel Pump

Before beginning any tests, it is important to identify the type of fuel pump in your Craftsman LT1000. There are two common types: the Two Hose Type and the Three Hose Type. The testing procedure will vary depending on the type of fuel pump in your machine.

Step 2: Access the Fuel Pump

Locate the fuel pump in your Craftsman LT1000. Depending on the model, it may be mounted differently. Once located, remove any necessary components to access the fuel pump. Ensure you have a clear view of the diaphragm and its surrounding areas.

Step 3: Prepare the Fuel Pump for Testing

For the Two Hose Type fuel pump, leave the hoses attached and only remove the screws that attach the fuel pump to the powerhead. Re-insert the screws and add a nut to each of them to securely clamp the fuel pump together.

For the Three Hose Type fuel pump, remove the pressure/vacuum hose that leads from the fuel pump to the crankcase while leaving the other hoses attached.

Step 4: Observe for Leaks

With the fuel line still attached to the engine, pump the primer bulb and observe the relevant areas for any fuel leaks.

For the Two Hose Type fuel pump, observe the pressure/vacuum operating hole on the back side of the fuel pump.

For the Three Hose Type fuel pump, observe the pump pressure/vacuum fitting from which you removed the hose.

Step 5: Identify a Faulty Diaphragm

If you notice any fuel leaking from the observed areas, it indicates a faulty diaphragm. A faulty diaphragm will require the fuel pump to be either rebuilt or replaced.

Step 6: Check for Repair Kits

Before replacing the fuel pump, check if a repair kit is available for your specific fuel pump model. Repair kits may not be available for all fuel pumps, in which case, replacement is necessary.

By following these steps, you can effectively check the fuel pump diaphragm of your Craftsman LT1000 and determine if any further action, such as repair or replacement, is needed.

Check the fuel line for blockages

Checking the fuel line for blockages is an important step in maintaining your Craftsman LT1000 fuel pump. Here's a detailed guide to help you through the process:

Before beginning, it is important to take necessary safety precautions. Disconnect the battery to prevent any accidental sparks that could ignite fuel or fuel vapors. Ensure there are no open flames or cigarettes nearby. Use a torch instead of an inspection lamp, as a broken bulb could pose a fire hazard.

Now, let's begin checking the fuel line for blockages:

• Locate the fuel line: The fuel line is the hose that connects the fuel tank to the engine, usually running under the floor of the car. It is typically made of metal or plastic, with flexible sections made of reinforced rubber hose or clear plastic tubing.
• Inspect for leaks and damage: Check the entire length of the fuel line for any signs of leaks or damage. Look for corrosion, cracks, or abrasion on the fuel line. Pay attention to the joints and connectors, as these are common sources of leaks. Inspect the carburetor first, as it is often the most common source of leaks.
• Check for blockages: If there are no apparent leaks, the next step is to check for blockages. Free both ends of the fuel line and use your mouth to blow gently through it. Do not use a high-pressure air line as it may cause damage. If you are unable to blow through the line, there is likely a blockage.
• Identify the source of the blockage: Blockages can occur at filters, kinks, or dents in the fuel line. If the blockage is at a filter, you may need to clean or replace it. Kinks or dents in the line may require straightening or repairing the affected section.
• Address blockages caused by dirt or rust: If you suspect that the blockages are due to dirt or rust in the fuel tank, you will need to remove, clean, flush, or replace the tank.
• Reassemble and test: Once you have cleared any blockages, reassemble the fuel line, ensuring all connections are secure and tight. Start the engine and observe if it is running smoothly without any issues.

Remember, working on the fuel system can be dangerous, so take your time and follow safety protocols. If you are unsure or uncomfortable with any part of the process, it is best to consult a professional or seek assistance from a qualified mechanic.

Check the fuel filter

To check the fuel filter on your Craftsman LT1000 lawn tractor, you will need to locate the filter itself. The fuel filter is usually found along the fuel line, which connects the fuel tank to the carburetor.

Once you have located the fuel filter, you can perform the following checks:

Visual Inspection

• Inspect the fuel filter for any signs of damage, such as cracks, holes, or leaks.
• Check the condition of the diaphragm inside the fuel filter. Make sure there are no pin holes or tears, as this could affect its performance.

Fuel Presence

Check both the inlet and outlet sides of the fuel filter to ensure that fuel is present. This can be done by disconnecting the fuel lines and observing if fuel is present at each end.

Vacuum and Pulse Line

Inspect the vacuum and pulse lines connected to the fuel pump. Ensure that the lines are tight and free from cracks or damage.

Fuel Flow

• Disconnect the fuel pump from the carburetor and place it in a cup.
• Turn the engine over and observe if there is fuel flow from the pump. There should be some flow when the engine spins, indicating that the fuel filter is allowing fuel to pass through.

If, after performing these checks, you find that the fuel filter is clogged or damaged, it is recommended to replace it with a new one. A clean and properly functioning fuel filter is essential for ensuring adequate fuel delivery to the engine.

Check the solenoid

To check the solenoid on your Craftsman LT1000, you will need to perform a series of tests.

Firstly, check if there is voltage on one side of the solenoid but not on the other. If there is, and the solenoid is being energised, it is faulty and should be replaced.

Next, put your voltmeter across the battery itself and try the starter. The voltage should not drop below 10 volts. If this is ok, move the positive lead to the hot side of the solenoid. Crank again, and the voltage should stay at around 10. If this is ok, put the positive probe on the case of the solenoid, assuming it's metal. The voltage here should be close to 0, as the case should be grounded.

Then, put the positive probe on some bare metal on the frame. Voltage should be close to 0. If not, your battery ground cable is not connected well, either at the battery or the frame.

Finally, put the positive lead on the connection that energises the solenoid (this should be a small-diameter wire). Voltage should be steady at battery voltage. If not, you have a bad connection/switch in the solenoid circuitry.

If you've performed all these tests and the solenoid is functioning, try a jumper cable straight from the battery negative terminal to the engine block, and the other jumper cable from the positive terminal to the positive post on the starter. If the mower starts, you could have a dirty ground connection where the negative cable comes off the battery and hooks to the frame. Or you could have a bad ground connection on your solenoid.

If you have voltage on both sides of the solenoid, the starter motor is likely at fault. If the starter motor turns on and creates a consistent hum, the starter is working fine, so replace the solenoid. If the starter motor does not turn on, the brushes in the starter motor may be worn out.

Frequently asked questions