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002 Inlet Tension Pop-Off Spring
002 Inlet Tension / Pop-Off Spring
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002 Inlet Tension Pop-Off Spring

Part Number: 002
Online Price: $2.00
002 Inlet Tension Pop-Off Spring | Carburetor Fuel Control for Low-Speed Tuning
Availability: In Stock.

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Description

002 Inlet Tension Pop-Off Spring for Diaphragm Carburetors


The 002 Inlet Tension Pop-Off Spring is a precision-calibrated component designed to regulate pop-off pressure in diaphragm-style carburetors. This spring plays a key role in controlling how fuel flows into the carburetor’s high and low side circuits, especially during low-speed engine operation, idle, and throttle transitions.


Pop-off pressure is the force required to unseat the inlet needle valve, allowing fuel to enter the metering chamber. This pressure is determined by the tension of the inlet spring and its installation height within the carburetor.


It’s important to clarify that pop-off pressure is not the same as fuel pressure. The fuel pump typically provides no more than 1 PSI. A 10 PSI pop-off pressure does not mean that the engine must generate 10 PSI of fuel pressure—it simply reflects how much force is needed to overcome the spring tension and open the valve.

The 002 spring offers a lighter tension profile, making it ideal for setups that require quicker needle actuation and enhanced fuel response at low RPMs.


Key Features:

  • Controls pop-off pressure for diaphragm-style carburetors
  • Enhances fuel metering precision at low engine speeds
  • Ideal for idle tuning and responsive throttle behavior
  • Compatible with many Tillotson, Walbro, and similar 2-stroke carburetors
  • Engineered for consistent tension and long-lasting performance

FAQ

Q1: What does the 002 Inlet Tension Pop-Off Spring do?
A1: It controls the pop-off pressure in diaphragm carburetors, regulating when the needle valve opens to deliver fuel—especially during low-speed engine operation.


Q2: Is pop-off pressure the same as fuel pressure?
A2: No. Pop-off pressure is the force needed to overcome the spring tension and open the inlet needle valve. Fuel pressure, typically around 1 PSI, is created by the fuel pump and is unrelated to pop-off readings.


Q3: Which engines or carburetors are compatible with the 002 spring?
A3: The 002 spring is compatible with many small 2-stroke engines using diaphragm-style carburetors, including Tillotson, Walbro, and similar models.


Q4: How do I tune pop-off pressure using the 002 spring?
A4: You can adjust pop-off pressure by changing the spring’s installation height or swapping to a spring with a different tension rating. A pop-off tester is recommended for accurate setup.


Q5: When should I use the 002 spring instead of other options?
A5: The 002 spring is best for low-RPM tuning where you want quicker needle valve opening and smoother throttle response. It’s ideal for idle and transition tuning in small engines.

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