Check that the jet has been cleared by blasting compressed air through the jet. -flush the pilot circuit through with carb cleaner, don't be stingy- give it a good wash out.-replace the pilot jet with a new one - inspect the air screw o-ring, if it's deformed or has hardened then replace it. This is a lean symptom and often occurs when a motor is cold. Replacement jets are inexpensive so it may be easier to just put a new one in. : 3) Clogged idle mixture circuit.Inside the CV carburetor there are a series of tiny passages connecting the mixture screw, pilot jet, and air intake jet located on the front face of the carburetor (pictured below). Can't see how the jet could be clogged again. Pretty frustrating as it only sat for a week in very mild weather. If the jet is still clogged, pass a small, stiff wire through the jet and soak the jet for another 10 minutes. 1) Pilot jet/slow jet - Affects mixture from idle to 1/3 throttle opening. There is an pilot (idle) jet on all carburetors too - these are normally left at 55 for most carburetors (28, 30, H30/31 and 34 series), on any engine size (since it's only feeding the engine at small throttle settings anyway). Spray the inside and outside of the carburetor with carburetor cleaner, ensuring all holes flow freely and the throttle and choke move without sticking. What are some indications of a rich pilot jet and/or screw setting? 7. All rights reserved. This has now happened 3 times with the same symptoms, same visual confirmation that the jet is not clogged, at least not completely clogged, and that a replacement then putting suspect jet back confirming the problem is with the jet. Pilot screw maladjusted Pilot jet, or air passage clogged Air bleed pipe bleed holes clogged Pilot passage clogged Air cleaner clogged, poorly sealed, or missing Starter plunger stuck open Fuel level in carburetor float bowl too high or too low Fuel tank air vent obstructed Carburetor holder loose Air cleaner duct loose. Blockage to the fuel inlet screens under the float valves. Turning in clockwise, will richen the pilot mixture. It acts like it's about to start and then just doesn't. Things to check whenever you have full starvation symptoms like this: These possibilities must be systematically eliminated one-at-a-time until the cause is isolated. Verify that the governor linkage is correct. Available at a welding supply store, these file-like wires are small enough to fit through most pilot jets and will push out stubborn clogs. Pilot/Idle Jet is Clogged Some Symptoms: Surges when on idle, will even out if you partially engage the choke. The pilot jet can also become clogged. These are the same on all Keihin PWK carbs. To remove the pilot jet, you need to pull it out gently. Blockage inside the fuel tank. Moderator: Site Team. You might be "idling" off the main jets due to clogged idle passages and a high idle setting (throttle plates too open). Reproduction in whole or in part without permission is prohibited. The pilot jet meters fuel to the "bottom end circuits" 2) Air screw - Meters air to pilot jet. Got a clogged pilot jet and contact cleaner alone won't clear it out? All rights reserved. : 36. This means they are adjusted OUT for more richness and IN … This forum is for techinical help and info for the XJR400. Stock jetting was 40 pilot, 140 main and the needle on the meddle clip. If you suspect a tank blockage, siphon most of the fuel from the tank and remove the petcock. If the pilot jet is clogged, it can be accessed by removing an adjustment screw on the outside of the carburetor. If your needle jet is missing or worn CVP carries new needle jets. 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