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022 Inlet Tension Pop Off Spring
022 Inlet Tension / Pop-Off Spring
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022 Inlet Tension Pop Off Spring

Part Number: 022
Online Price: $2.00
022 Inlet Tension Pop-Off Spring – Controls Fuel Entry in Diaphragm Carburetors
Availability: In Stock.

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Description

022 Inlet Tension Pop-Off Spring – Controls Fuel Flow in Diaphragm Carburetors


The 022 Inlet Tension Pop-Off Spring plays a critical role in regulating fuel delivery in diaphragm-style carburetors, especially during low-speed and idle operation. It helps determine the pop-off pressure—the point at which the needle valve opens to allow fuel into the carburetor's metering chamber.


This spring is often misunderstood. While it affects pop-off pressure, it does not control or reflect fuel pressure from your pump. Fuel pumps used with these carburetors typically produce around 1 PSI. So, if your pop-off pressure is 10 PSI, that does not mean your fuel system needs to produce 10 PSI to function properly.


What Pop-Off Pressure Really Means:

  • Pop-off pressure is the point at which the inlet needle lifts off its seat
  • Controlled by the spring tension and installation height
  • Not directly related to your fuel pump’s output pressure
  • A key factor in carburetor tuning for small engines, karts, and 2-stroke performance setups


Product Details:

  • Part Number: 022
  • Precision tension rating for accurate tuning
  • Fits most Tillotson-style diaphragm carburetors
  • Ideal for karting, chainsaws, and 2-stroke performance engines
  • Helps optimize fuel delivery curve at low RPM


Important Tuning Note:

Always test pop-off pressure using a pop-off gauge, and refer to your engine or carburetor manufacturer’s recommended specs. Incorrect assumptions about fuel pressure vs. pop-off pressure can lead to improper tuning and performance issues.

FAQ

Q1: What does the 022 Inlet Tension Pop-Off Spring do?
A: This spring helps regulate pop-off pressure in diaphragm carburetors by controlling the force needed to lift the inlet needle valve. It directly impacts how and when fuel flows into the metering chamber, especially at low engine speeds.


Q2: Is pop-off pressure the same as fuel pressure?
A: No. Pop-off pressure is the pressure at which the inlet needle opens, determined by spring tension. Fuel pressure is generated by the pump (typically around 1 PSI) and is not directly related to pop-off values like 10 PSI.


Q3: How do I know if I need to change the pop-off spring?
A: If your engine is flooding, bogging, or running lean at low RPM, adjusting or replacing the pop-off spring may help. Use a pop-off gauge and follow carburetor tuning guidelines to dial in the correct spring rate.


Q4: What carburetors is this spring compatible with?
A: The 022 spring is compatible with most Tillotson-style diaphragm carburetors, including HL and HR models commonly used in karting, chainsaws, and 2-stroke racing engines.


Q5: Can I adjust pop-off pressure without replacing the spring?
A: Yes, in some cases you can adjust pop-off pressure by changing the spring’s installed height using shims. However, if major adjustment is needed, switching to a different spring rate is more effective and consistent.

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