Harley-Davidson X440 Genuine Cylinder Head Gasket – HDH12251ACJ000S | Fits X440, X440 OBDII & X440T

Harley-Davidson X440 Genuine Cylinder Head Gasket – HDH12251ACJ000S | Fits X440, X440 OBDII & X440T

If you are opening the top end of your Harley-Davidson X440, this HDH12251ACJ000S is the genuine OEM cylinder head gasket you should match before reassembly. Your official EPC screenshot identifies it as GASKET CYLINDER HEAD, shows an MRP of ₹320, and confirms fitment for X440 (Sept, 2023), X440 OBDII (May, 2025), and X440T (Jan, 2026). Public seller pages also list the same part number as GASKET CYLINDER HEAD (HDH12251ACJ000S) at the same ₹320 price point, which supports both the code match and the public market identity of the part.

In buyer language, this part is commonly searched as the X440 head gasket, cylinder head gasket, top head gasket, top-end gasket, or engine head sealing gasket. Buyers usually replace it during cylinder head removal, piston work, top-end rebuilds, compression repair, overheating-related repair, or when fixing leaks after the engine has been opened. Unlike low-cost paper gaskets, a head gasket is a critical sealing part and should never be reused once disturbed.

This page is written to rank for the exact part code HDH12251ACJ000S and real buyer searches like Harley X440 head gasket, X440 cylinder head gasket, and X440 top end gasket.

What This Product Is

This is the genuine cylinder head gasket for the Harley-Davidson X440 engine platform. In practical buyer language, this is the top-end sealing gasket installed between the cylinder and cylinder head during engine assembly.

Verified Compatibility

• Harley-Davidson X440 (Sept, 2023)
• Harley-Davidson X440 OBDII (May, 2025)
• Harley-Davidson X440T (Jan, 2026)

Important Fitment Note

This listing is kept conservative and tied to the exact models visible in your official catalogue screenshot. Do not assume fitment for other 440-family engines unless the exact part number matches. A cylinder head gasket must always be purchased by exact code, not by visual similarity.

Why Buyers Need It

• Helps seal combustion pressure, oil passages, and mating surfaces correctly during top-end reassembly
• Reduces risk of compression loss or leakage after rebuild work
• Useful during cylinder head removal, piston work, and engine repair
• Critical genuine sealing part that must be replaced during reassembly
• Better sealing confidence than unknown local gasket alternatives

Key Features

• Genuine OEM part number: HDH12251ACJ000S
• Part identity in EPC: GASKET CYLINDER HEAD
• Confirmed fitment from EPC: X440, X440 OBDII, X440T
• Public seller listing matches same code and price point
• Essential top-end engine sealing part
• Relevant during head removal and top-end rebuild work
• MRP shown in catalogue: ₹320
• Best bought only by exact part number match

Common Purchase Reasons

• Cylinder head removed during service
• Piston or valve-train work
• Compression repair or leak-related repair
• Old head gasket damaged during dismantling
• Preventive replacement during reassembly

Why Genuine Matters

• Head gasket profile, thickness, and passage cut-outs must match exactly
• Incorrect gasket specification can affect compression, sealing, and engine reliability
• Better fit confidence than generic sheet-cut or uncertain aftermarket alternatives
• Critical part where repeat labor costs can far exceed gasket cost

Fitment / Return Prevention Note

Please buy this only after matching the exact part number HDH12251ACJ000S. Engine gaskets should never be ordered by appearance alone. Confirm the application by EPC, VIN, or engine teardown requirement before purchase.

What’s in the Box

• 1 x Cylinder Head Gasket

Installation & Workshop Notes

• Clean both mating surfaces fully before installing the new gasket
• Do not reuse a head gasket after dismantling
• Check head flatness, cylinder surface, studs, and related components during top-end work
• Use the correct torque sequence and torque values during reassembly
• After assembly, inspect for leaks and confirm proper compression behavior

Technical Details

• Customer-facing brand: Harley-Davidson X440 Genuine
• Catalogue / backend source: Hero-supported official parts catalogue
• Part Number: HDH12251ACJ000S
• Product Name: Gasket Cylinder Head
• Confirmed Models: X440, X440 OBDII, X440T
• Pack Quantity: 1 piece
• MRP: ₹320

Buyer-Focused FAQs

Q1. What is HDH12251ACJ000S used for?
It is the genuine cylinder head gasket, used when the cylinder head is refitted to help seal combustion pressure and the top end of the engine properly.

Q2. Which bikes does it fit?
Your official catalogue screenshot confirms X440, X440 OBDII, and X440T.

Q3. Should I reuse the old head gasket?
No. A head gasket should be replaced once the engine is opened. Reusing it increases the risk of poor sealing, compression issues, and leaks.

Q4. Is this the same as the cylinder gasket?
No. Cylinder gasket and cylinder head gasket are different sealing parts used at different interfaces in the top end.

Q5. Why buy genuine for this part?
Because correct gasket profile and thickness matter. A genuine head gasket is critical to rebuild quality and long-term sealing reliability.

SEO Tags

HDH12251ACJ000S, Harley X440 head gasket, X440 cylinder head gasket, Harley-Davidson X440 top end gasket, X440 engine head gasket, genuine X440 head gasket, X440 rebuild gasket, X440 OBDII head gasket