420890244 Sea-Doo Standard Piston Assembly 99.94mm | Genuine OEM BRP Part

🔧 Product Description

Genuine Sea-Doo 1503 4-TEC Standard Piston Assembly, 99.94 mm - Part Number: 420890244

A genuine BRP standard-size 99.94 mm piston assembly for selected 1503 Rotax 4-TEC engines. The catalogued assembly includes the matched standard piston-ring set but does not include the piston pin or circlips unless separately supplied.

⚙️ Key Features

• Genuine BRP cast/forged production-specification piston
• Standard nominal piston diameter: 99.94 mm
• Matched to the original 1503 cylinder-bore class
• Includes the standard piston-ring set
• Cylinder bore, piston-to-wall clearance and ring end gaps must be measured during engine assembly

📋 Kit / Assembly Contents

• 1 × standard 99.94 mm piston - supplied under assembly 420890244
• 1 × standard piston-ring set - 420890380
• Piston pin - 420216250 - serviced separately and not identified as included
• Piston-pin circlips - 420845580 - serviced separately and not identified as included

🚤 Compatibility

Commonly used on

• GTX 4-TEC and GTX Supercharged 1503 models
• RXP 215 and RXT 215 model families
• RXP-X/RXT-X 255 and 260 model families where 420890244 is specified
• Wake Pro 215
• Selected 1503-powered Sportster, Speedster and Challenger jet boats
• Other 1503 4-TEC engines whose crankshaft/piston diagram lists 420890244

Typically suits

• HP Range: Approximately 155-260 HP across verified piston applications
• Engine / Drive Type: 1503 cc three-cylinder Rotax 4-TEC naturally aspirated or supercharged engine
• Year Range: Approximately 2002-2016, model dependent
• Serial / Model Identification: Confirm the cylinder-bore class, engine identification number and crankshaft/piston diagram. Do not install a standard piston in a worn or machined oversize bore.

🔌 Function

Transfers combustion pressure through the connecting rod to the crankshaft while the ring pack seals compression, controls oil and transfers heat into the cylinder wall.

⚠️ Common Signs of Failure

• Low compression or excessive crankcase blow-by
• High oil consumption or blue exhaust smoke
• Piston slap, knocking or metallic noise
• Scuffed skirt, collapsed ring lands or seized rings
• Cylinder damage following overheating, detonation or lubrication loss

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 420890244 - current verified standard-size piston assembly reference
• 420890245 - separate 100.19 mm oversize piston assembly; not a direct substitute without approved cylinder machining

OEM / Related Numbers

• 420890244
• 420890380
• 420216250
• 420845580
• 420890245 - oversize counterpart
• 420890381 - oversize ring set

Aftermarket / Verified Equivalents

• Australian Jet Ski Parts: AM4TECSTD standard forged-piston kit family
• Aftermarket 99.94/standard 1503 4-TEC piston kits must be balanced and measured as an engine set

📦 Condition

• Genuine Sea-Doo / BRP OEM part
• Brand new
• Supplied in genuine BRP or equivalent protective packaging