Yamaha - Pilot Jet #37.5 - Carburetor Fuel Metering Component - 7CU-E4142-37-A0

Overview

Pilot jets are small, but they make a big difference in how an engine behaves at idle and low throttle. When one gets clogged or worn, you’ll notice it right away—rough idle, stalling, or sluggish response off the line. I’ve cleaned plenty, but sometimes replacing it is the only way to get things running right again. When it’s dialed in, the engine idles smooth and transitions clean into throttle.

Key Features

• Low-Speed Fuel Control – Regulates fuel delivery at idle and low throttle for smooth operation.
• Precision Sized Jet – Calibrated at 37.5 for accurate fuel-air mixture in carbureted systems.
• OEM Fit and Threading – Installs cleanly into the carburetor without modification.
• Improves Idle Stability – Helps eliminate stalling, hesitation, and uneven low-speed performance.

Engine & Boat Compatibility

Designed for Yamaha outboard engines equipped with carbureted fuel systems that utilize a pilot jet for low-speed fuel control. Commonly used across a range of Yamaha outboards where precise idle and low-throttle performance is required.

FAQ

Q: What are signs the pilot jet is clogged?
A: Rough idle, stalling at low speeds, or hesitation when you first throttle up are common signs.

Q: Can I clean this instead of replacing it?
A: You can try, but if buildup is heavy or performance doesn’t improve, replacement is the better option.

Q: Does changing jet size affect performance?
A: Yes, the size directly impacts the fuel mixture, so it’s important to use the correct specification.

Q: How does fuel quality affect the pilot jet?
A: Dirty or old fuel can clog the jet quickly, especially if filters aren’t maintained.

Q: Is installation difficult?
A: It’s straightforward if you’re already working inside the carburetor—just make sure it’s properly seated.