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001 Inlet Tension Pop-Off Spring
001 Inlet Tension Pop-Off Spring
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001 Inlet Tension Pop-Off Spring

Part Number: 001
Online Price: $2.00
001 Inlet Tension Pop-Off Spring | Low-Tension Carburetor Tuning Spring
Availability: In Stock.

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Description

001 Inlet Tension Pop-Off Spring for Diaphragm Carburetors


The 001 Inlet Tension Pop-Off Spring is a precision-engineered component designed to regulate pop-off pressure in diaphragm-style carburetors. This spring plays a critical role in controlling how fuel flows into the high and low side circuits, particularly during low-speed engine operation such as idle and throttle transition.


Pop-off pressure refers to the amount of pressure required to open the carburetor’s needle valve, allowing fuel into the metering chamber. This pressure is determined by two key factors:

  • The tension of the inlet spring (in this case, the 001)
  • The installation height of the spring in the carburetor


It’s important to understand that pop-off pressure is not the same as fuel pressure. Fuel pressure, typically delivered by the pump, is about 1 PSI. A pop-off pressure reading of 10 PSI, for example, does not mean that your fuel pump must deliver 10 PSI. Instead, it reflects the amount of pressure needed to unseat the needle valve against the spring force.


The 001 spring offers the lowest tension in this series, allowing for the quickest needle valve response and earliest fuel delivery, which can be ideal for certain engine tuning setups where rich fuel delivery is desired at very low RPMs.


Key Features:

  • Lightest pop-off spring tension in the series
  • Enables early needle valve actuation for rich low-speed operation
  • Ideal for fine-tuning diaphragm carburetors in 2-stroke engines
  • Compatible with Tillotson, Walbro, and similar carburetors
  • Engineered for consistent tension and reliable performance

FAQ

Q1: What is the purpose of the 001 Inlet Tension Pop-Off Spring?
A1: It regulates the pop-off pressure in diaphragm carburetors, allowing the needle valve to open at lower pressures. The 001 offers the lightest spring tension in the series, ideal for early fuel delivery.


Q2: Is pop-off pressure the same as fuel pressure?
A2: No. Pop-off pressure refers to the pressure needed to overcome the spring tension and open the inlet needle. Fuel pressure, typically 1 PSI, is generated by the fuel pump and is not the same as pop-off pressure.


Q3: Which carburetors are compatible with the 001 spring?
A3: The 001 spring is compatible with many diaphragm-style carburetors, including Tillotson, Walbro, and similar 2-stroke small engine models.


Q4: When should I use the 001 spring?
A4: Choose the 001 spring when you want the lightest resistance for needle opening—ideal for rich low-speed operation, early throttle response, or specific racing and performance setups.


Q5: How is pop-off pressure adjusted?
A5: Pop-off pressure can be adjusted by changing the spring type (like switching to the 001) and modifying the installation height. A pop-off pressure tester ensures accurate tuning.

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