Husqvarna Cylinder Piston Kit 504016802 55 Rancher 51 46mm 503609671 OEM

Husqvarna Cylinder Piston Kit 504016802 55 Rancher 51 46mm 503609671 OEM.

Restore Maximum 150+ PSI Compression & Factory Cutting Muscle: Genuine Husqvarna Top-End

Eliminate dead cylinder compression, severe piston scoring, high-RPM bogging, and stubborn hard-starting on your Husqvarna chainsaw. This Genuine Husqvarna Factory OEM 46mm Cylinder & Piston Kit (Part Number 504016802 / 504 01 68-02) is the authentic complete top-end rebuild package engineered explicitly for Husqvarna 51, 55, and 55 Rancher commercial chainsaws (directly replacing and superseding prior part numbers 503609671, 503758171, 503758172, and 5036096-71) . Rebuilding a classic pro saw with uncalibrated aftermarket cylinder kits often results in poor port timing, loose squish clearances, and premature heat seizure.

Precision-cast in Sweden to Husqvarna’s rigorous metallurgical standards, this 46mm top end features an ultra-durable Nikasil-plated bore engineered for high wear resistance, rapid heat dissipation, and low friction under continuous heavy cutting. The matching high-silicon aluminum piston is balanced to factory specs and includes an authentic semi-inlaid compression ring, precision-ground 12mm wrist pin, and tempered wire circlips. Because the Husqvarna 51 and 55 share the identical magnesium crankcase, crankshaft, stroke ( $32\text{ mm}$ ), and intake partition block, this kit serves as the exact direct OEM replacement for the 55/55 Rancher ( $53.2\text{ cc}$ ) and a seamless bolt-on "big-bore" displacement upgrade for older 45mm Husqvarna 51 saws (increasing displacement from $51\text{ cc}$ to $53.2\text{ cc}$ with zero crankcase machining).

This authentic factory rebuild package is cataloged under Husqvarna OEM Part Number 504016802 (504 01 68-02 / 5040168-02 / Cylinder Kit / Cylinder Piston Assembly 46mm) and directly supersedes 503609671 (503 60 96-71), 503758171 (503 75 81-71), and 503758172 (503 75 81-72) .

Why This Genuine Husqvarna 504016802 OEM Cylinder Kit is the Pro Rebuilder's Standard:

100% Genuine Factory OEM Top-End: Manufactured to Husqvarna Sweden blueprints for flawless port matching, pulse hole alignment, and factory combustion chamber geometry.

Hard-Chromed / Nikasil Bore Plating: Micro-porous bore lining retains lubricating 2-cycle oil under extreme RPMs, preventing heat scuffing and premature bore wear.

Restores Full Commercial Compression: Re-establishes snappy throttle response, solid high-idle stability, and full-load wood-clearing torque ( $150+\text{ PSI}$ ).

Popular 46mm Big-Bore Upgrade for Husqvarna 51: Directly replaces the stock 45mm top end to boost engine displacement from $51\text{ cc}$ to $53.2\text{ cc}$ with zero modifications needed.

Complete Rebuild Components Included: Arrives with matched 46mm cylinder, cast alloy piston, piston ring, 12mm wrist pin, and twin wire circlips.

Standard M10 Decompression Port: Features factory-threaded M10 decompression valve port (accepts standard decomp valve or OEM blanking plug # 503552201).

Technical Specifications:

Brand: Genuine Husqvarna (OEM Factory Original)

Part Number: 504016802 (504 01 68-02 / 5040168-02)

Supersedes / Prior Part Numbers: 503609671 (503 60 96-71), 503758171 (503 75 81-71), 503758172 (503 75 81-72)

Component Type: Complete Engine Top-End Cylinder & Piston Assembly

Cylinder Bore Diameter: 46 mm (Stroke: 32 mm | Displacement: 53.2 cc)

Wrist Pin Diameter: 12 mm Standard Husqvarna Small-End Fitment

Decompression Port: Threaded M10x1.0 Side Port (Valve / Plug sold separately)

Intake Interface: Direct-Fit for Standard 51/55 Plastic Intake Partition Block & Impulse Channel

Kit Contents: 46mm Cylinder, Piston, Piston Ring, 12mm Wrist Pin, and Two (2) Wire Circlips (Connecting rod needle bearing sold separately)

Condition: Brand New in Official Factory Packaging

Guaranteed Equipment Model Compatibility Matrix:

Specifically engineered for direct fitment across Husqvarna and Jonsered professional chainsaw platforms:

Husqvarna 55 & 55 Rancher (Direct OEM Replacement):

Fits Husqvarna 55 Rancher (All production runs, EPA models, and serial breaks).

Fits Husqvarna 55 (Standard 53.2cc professional chassis).

Specifications

• Compatible Brand: For Husqvarna
• Type: Cylinder Piston Kit
• Unit Type: Unit
• Assembly Required: Yes
• Model: Husqvarna 504016802
• Compatible Product: Chainsaw
• Unit Quantity: 1

Condition: New