How to Remove a Damaged Pilot Jet From a Mikuni Carb

The pilot jet in a carburetor provides for the correct mixture of fuel and air into an engine when in idle. The pilot jet tends to be adjustable in a Mikuni carburetor, allowing a user to twist it to increase or decrease the engine idle speed when running. However, a damaged pilot jet will alter the engine combustion mixture, causing the system to run improperly. Rather than trying to repair it, a user is better served with just replacing the jet altogether.

Instructions

1

Purchase a new Mikuni pilot jet for your model carburetor. Locate the existing pilot jet on the vehicle. Loosen and remove the fuel line and manifold connection if other parts are blocking access to the pilot jet.

2

Insert a flathead screwdriver into the top of the pilot jet. Twist it loose. Make sure you do not lose the jet and its spring when you remove them.

3

Insert the new pilot jet into the spring. Place the two back onto the Mikuni carburetor and use the screwdriver to tighten the new pilot jet back into the carburetor. Carefully tighten the jet until it screws all the way home into the carburetor body. Reattach the fuel line and manifold if necessary.

4

Loosen the pilot jet two complete turns once it is twisted all the way in. Start the vehicle and let the engine warm up. Listen to the idle speed of the engine. Twist the pilot jet further out, a quarter of a turn each time, until the engine speed reaches a normal idle speed.