Royal Enfield Thunderbird 500, Classic 500 EFI & Himalayan 411 BS4 Pulse Air Valve (PAV / Secondary Air Valve) – 510187/B

Genuine Royal Enfield Pulse Air Valve (PAV) for specific older Royal Enfield secondary-air / emission-control systems. The current genuine service part number is 510187/B. Royal Enfield’s factory description is PULSE AIR VALVE (TCI); model-specific catalogues also use Pulse Air Valve - Ucal.

Buyer terms include PAV valve, secondary air valve, secondary air injection valve, air injection valve, emission-control valve and air suction valve. It is not an EVAP purge valve, not a fuel valve and not an inlet/exhaust valve inside the engine.

Quick Buyer Check

What Does 510187/B Do?

The Pulse Air Valve forms part of Royal Enfield’s secondary-air emission-control system. It works with model-specific hoses, adaptors, clips and cylinder-head/exhaust-side plumbing to control fresh-air flow into the exhaust-side circuit as designed by the factory.

Part Number / Supersession

Current genuine-parts databases explicitly route 510187/A to 510187/B.

Confirmed Compatibility

Critical Thunderbird 350 Correction

Do not list Thunderbird 350 or Thunderbird X 350 as confirmed fitment. Thunderbird 350 and 500 appear together in a combined catalogue, but the generation uses different 350-TCI and 500-EFI arrangements. Text extraction can lose blank model columns and make a 500-only part look common to both. This listing therefore keeps Thunderbird 350 out unless an exact VIN/EPC or removed genuine part specifically confirms 510187/B.

Classic 350 – Explicit Exclusion

The checked Classic 350/500 catalogue shows 510187 under the 500 EFI column and NA under 350CC. Classic 350 UCE is therefore not claimed.

Himalayan 411 Fitment

The Himalayan BS4 / Euro 4 parts catalogue directly lists 510187/B – Pulse Air Valve – Qty 1. This supports Himalayan LS410 / 411cc BS4-Euro 4. Do not automatically extend this to Himalayan 411 BS6 / Euro 5 or Scram 411.

Bullet 500 – Verify Before Ordering

Some current sellers cross-list 510187/B in Bullet 500 categories, but Royal Enfield used different PAV service families across production periods. Do not advertise universal Bullet 500 fitment; verify the old part or VIN/EPC.

Similar / Related Parts

PAV vs EVAP

PAV / secondary-air and EVAP / fuel-vapour control are different systems. Do not confuse 510187/B with an EVAP purge valve, charcoal canister, fuel-vapour hose, injector, throttle body or carburettor air-cut valve.

Possible Symptoms

A PAV-system problem may involve cracked hoses, damaged valve ports, loose plumbing, broken mounting or abnormal air leakage. Deceleration popping alone does not prove the valve is faulty; exhaust leaks, fuelling, ignition, valve condition and hose leaks can cause similar symptoms.

Inspect Before Replacing

• Air-filter-to-PAV hose
• Braided PAV hose
• PAV adaptor hose / cylinder-head-side plumbing
• Hose clips and clamps
• PAV bracket
• Bushes and grommets
• Related sealing points

When Should It Be Replaced?

• Valve body or hose port is cracked.
• Mounting section is damaged.
• Internal valve function is confirmed faulty after diagnosis.
• Original unit is missing.
• Factory restoration requires the original PAV system.
• Exact EPC or removed part confirms 510187/B or older 510187/A.

What You Receive

1 × Genuine Royal Enfield Pulse Air Valve / PAV Unit – 510187/B.

Not Included Unless Physically Supplied

• PAV bracket
• Hoses
• Clips / clamps
• Bushes
• Grommets
• Adaptor
• O-rings / seals
• Mounting hardware

Installation Notes

• Confirm 510187/B and exact motorcycle application before opening.
• Allow engine/exhaust area to cool.
• Photograph original hose routing before removal.
• Inspect all hoses for cracking and hardening.
• Connect every hose to the correct PAV port.
• Keep hoses clear of hot and moving parts.
• Check for abnormal air/exhaust leakage after installation.
• Professional installation is recommended where the system has been modified or deleted.

Not Confirmed / Do Not Order by Model Name Alone

Price Note

Current Indian exact-SKU specialist listings checked for 510187/B show ₹1,102. An older 2024 price list showed ₹1,146; the listing uses the current ₹1,102 retail reference rather than the older value.

Ordering & Return Note

Verify part number, exact model, emission generation and existing PAV arrangement before opening or installation. Correctly supplied spare parts are not returnable for incorrect selection, wrong diagnosis, mechanic recommendation, fitment mismatch or change of mind. Wrong/damaged/missing-item claims require the applicable complete unboxing video within the stated claim window.

FAQs

What is 510187/B?
Genuine Royal Enfield Pulse Air Valve (PAV / TCI), an external secondary-air emission-control valve.

Does it fit Thunderbird 500?
Yes, on the applicable 500 EFI PAV system.

Does it fit Thunderbird 350?
Not claimed. Verify exact VIN/EPC if an older motorcycle appears to use the same number.

Does it fit Classic 500 EFI?
Yes, where the 510187 PAV arrangement is specified.

Does it fit Classic 350 UCE?
No fitment is claimed; the checked factory catalogue marks the 350cc application NA.

Does it fit Himalayan 411?
Yes for the directly documented LS410 / 411cc BS4-Euro 4 PAV configuration. Do not automatically extend to BS6.

Does it fit Rumbler 500?
Yes. The Rumbler 500 catalogue directly lists 510187/B.

Are hoses included?
Do not assume so; hoses, bracket, bushes, grommets and adaptors are separately catalogued unless physically supplied.

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