Rotax 1630 engine

October 16, 2026

Rotax 1630 Engine

for SEADOO and WILLIAMS jet boats

The Rotax ACE 1630 is the next-generation evolution of the Rotax 1503 4-TEC. Launched in 2016 in its 300 hp supercharged version, it gradually replaced the 1503 4-TEC in the range, with 130, 170, and 230 hp versions, followed more recently by 325 and 350 hp high-performance variants.

Are you looking for maintenance and replacement parts for your Rotax ACE 1630 engine? At Rotax Tender Parts, we offer parts for SEADOO jet skis and WILLIAMS boats equipped with the Rotax 1630. Our range includes engine components, filters, ignition parts, sensors, and electrical components. Check the original OEM part number, engine version, and model before ordering: the fact that the 1630 replaced the 1503 in the range does not mean it can directly replace it in all installations, nor that their parts are interchangeable. Some are, but not all.

Find parts for your Rotax 1630 engine

Engine parts
Fuel system
Ignition
Sensors
Electrical parts
Cooling
Oil and filters
Gaskets and seals
Impeller housing parts
Other

Rotax 1630 engine applications

WILLIAMS boats:

From 2021: WILLIAMS 435 Sportjet (Sport version)
From 2021: WILLIAMS 400 Sportjet
From 2021: WILLIAMS 460 Sportjet
From 2021: WILLIAMS 520 Sportjet

SEADOO jet skis:

This list of models combines information from our product pages and the model year data provided for this page. It only concerns Rotax 1630 versions. The compatibility of a common part does not confirm the presence of a given engine and does not guarantee that every listed part fits every model. Confirm the engine, model year, and original OEM part number before ordering.

350 hp

2027: GTX Limited 350; RXP-X 350; RXT-X 350

325 hp

2024–2026: RXP-X 325; RXT-X 325.
2027: RXP-X 325; RXT-X 325
2027: RXT-X 325

300 hp

2016–2023: RXP-X 300; RXT-X 300, including RS / XRS variants when specified on the product page.
2016–2026: GTX Limited 300.
2016–2024: GTX 300, listed separately in our product descriptions.
2024–2026: GTR-X 300.
2024–2027: Wake Pro 300
2027: GTR-X 300

230 hp

2017: GTX Limited 230, mentioned in our pressure and temperature sensor sheet.
2017–2026: GTR 230.
2017–2026: Wake Pro 230; the provided ranges 2017–2023 and 2024–2027 have been grouped, with the 2027 model year listed separately below.
2018–2026: GTX 230.
2018–2019: RXT 230, explicitly listed in our camshaft sensor compatibility information.
2024–2026: Explorer Pro 230.
2027: GTR 230; GTX 230; Wake Pro 230; Explorer Pro 230.
2027: GTX 230.
2027: Wake Pro 230; Explorer Pro 230.
2027: Explorer Pro 230.

170 hp

2020–2026: GTI SE 170; GTX 170.
2020–2023: Wake 170, mentioned in our camshaft sensor and engine mount sheets.
2019–2026: FishPro Sport 170, according to the provided list; our product pages differ on the designation of the FishPro 2019 engine. Therefore, confirm the engine for this model year before ordering.
2022–2026: FishPro Trophy 170.
2023–2026: Explorer Pro 170.
2027: GTI SE 170.
2027: GTX 170.
2027: FishPro Sport 170.
2027: FishPro Trophy 170.
2027: Explorer Pro 170.

130 hp

2020–2026: GTI 130; GTI SE 130.
2022–2026: FishPro Scout 130.
2027: GTI 130.
2027: GTI SE 130.
2027: FishPro Scout 130.

The model year ranges do not constitute an exhaustive list of manufacturer-verified compatibility. Some catalog descriptions mix 1503 and 1630 applications; always check the installed engine and the part number for each part. (see below, our FAQ section to identify your engine)

Common Rotax 1630 Parts

The following selection lists spare parts found in the Rotax 1630 engine. Click an "Add to Cart" thumbnail to add one unit of the product to your cart and access the cart. If the version or kit requires a choice, the "Choose Version" thumbnail opens the product page. Select a part or part number to open its page. Compatibility may depend on the engine version, original part number, and installed configuration. Use the OEM part number as a reference, then discover the available compatible aftermarket parts. OEM part numbers identify replacement parts, not necessarily OEM products.

Part	OEM Part Number	Function
Oil Filter	420956744	Engine oil filtration; check the original filter part number.
NGK DCPR8E Spark Plug	5297630 / 707000246 / 715900637 / 296000421 / 715900642	Ignition; confirm the recommended spark plug for your engine.
Ignition Coil	420666142	Spark production.
35 A / 12 V Relay, Single Unit	278002822 / 278003828	Switches electrical circuits on listed installations.
35 A / 12 V Relay, Pack of 5	278002822 / 278003828	Switches electrical circuits on listed installations.
Starter Solenoid Relay	278000513 / 278002347 / 278001802 / 278001766	Switches starter power.
117/86 Tooth Double Sprocket	420834915	Supercharged Rotax 1630 only
12 V Power Relay	278003012	Switches electrical power.
Fuel Pump Strainer, Pack of 2	270600113	Fuel pre-filtration on listed installations.
Crankshaft Position Sensor	420966575 / 420966570	Crankshaft position monitoring.
Camshaft Position Sensor	290664040 / 420664040 / 420664041 / 420664042 / 420664045 / 420664046	Camshaft position monitoring; check the sensor part number.
Camshaft Position Sensor, separate product page	420664045	Camshaft position monitoring.
Pressure and Temperature Sensor	Not specified on the product page	Pressure and temperature monitoring on the listed 1630 applications.
Right Throttle Position Sensor	278002283	Throttle control monitoring; right side only.
1630 ACE 300 hp Cylinder Head Gasket	420950772	Cylinder head sealing.
Cylinder Head Gasket Kit, 300 Version	Not specified on the product page	Cylinder head sealing; select the correct 300 hp variant.
Supercharger Assembly	420893566 / 420893567	Supercharging on the listed supercharged configurations.
1630 300 hp Piston Kit, 3 Cylinders, STD Size	420892738	Piston assembly replacement; standard bore.
1630 300 hp Piston and Ring Kit, +0.25 mm	420892738	Engine rebuild for cylinders machined to the corresponding oversize.
1630 300 hp Piston and Ring Kit, +0.50 mm	420892738 / 420916472	Engine rebuild for cylinders machined to the corresponding oversize.
Dual Valve Spring Kit	5238180 / 0462526	Valve spring tension; confirm the cylinder head configuration.
Inconel Triple-Gorge Intake / Exhaust Valve Kit	Not specified on the product page	Intake and exhaust control; check the valve dimensions and seats.
Bronze Valve Guides	5253929	Valve stem guidance; confirm compatibility with the cylinder head.
Engine Mount Components	250200018 / 270001081	Engine support and vibration isolation; check the installed mounting configuration.
Engine Mount Kit, 3 Pieces	270001081 / 270001096	Engine support and vibration isolation on the listed models.
Yellow Impeller Housing Wear Ring, 161 mm	267000638 / 267000917	Impeller housing clearance control; check the diameter and part number.
Impeller Shaft Removal Tool	Not specified on the product page	Shop tool for shaft removal; check the jet pump configuration.
Jet Pump Bearing and Seal Installation Tool	Not specified on the product page	Shop tool for bearing and seal installation.
Fuse Box Contacts, Pack of 80	No individual OEM part number listed	Electrical connection repair; compare the contact dimensions and their electrical specifications.
Connecting Rod Bearing Kit	Not specified in the product sheet	Conrod bearing support; confirm the dimensions and repair size.
3-Inch Intake Filter Kit	Not specified in the product sheet	Air intake adaptable for supercharged configurations; confirm adapter and installation compatibility.

Products with conflicting engine descriptions or uncertain part identification are not presented here as confirmed 1630 applications. Check each product sheet and the original part before ordering.

Common Rotax 1630 Problems

The symptoms below may affect several components or systems. These are possible causes, not a diagnosis or troubleshooting guide.

The engine will not start: battery, starter relay, starter, electrical supply, wiring and connectors, fuel pump, fuel supply, or ignition components.
Engine misfires: spark plugs, ignition coils, injectors, fuel supply, wiring, sensors, or cylinder compression.
Lack of power: injection, ignition, air intake, supercharger on supercharged versions, cylinder compression, or propulsion system components such as the turbine and wear ring.
Fault code displayed: sensors, electrical supply, wiring, connectors, or the system identified by the code. A fault code is not enough to confirm that a particular part needs to be replaced.

To learn more about fault codes, see our Rotax fault code list for Sea-Doo and Williams and our guide to decoding Rotax fault codes on Sea-Doo and Williams.

How to identify the correct ROTAX Ace 1630 part?

Not sure which Rotax part to choose? Send us a photo of the part, its OEM part number, and the model of your engine or Williams / Sea-Doo. We can help you identify the appropriate replacement part.

Identify my part from a photo

ROTAX 1630: Frequently Asked Questions - FAQ

What is the Rotax ACE 1630 engine?
A 1,630 cc three-cylinder four-stroke marine engine used on certain Sea-Doo personal watercraft and Williams Sportjet boats. This engine succeeds the Rotax 1503 - 4TEC engine, notably with a longer piston stroke, allowing it to reach 1,630 cc.
Where can I find the Rotax ACE 1630 engine serial number?
Look for the engine identification marking; use your model's manual to locate it, not the hull identification number.
Are Sea-Doo Rotax 1630 parts compatible with Williams boats?
Some engine parts are common to the WILLIAMS boats listed above. Some engine parts are shared; check the OEM part numbers. Marine-specific components, especially the exhaust and heat exchangers, may differ.
Which Sea-Doo models use the Rotax ACE 1630 engine?
Certain versions of the GTI / GTI SE, GTX / GTX Limited, GTR / GTR-X, RXP-X, RXT / RXT-X, Wake / Wake Pro, FishPro, and Explorer Pro; see the model years above.
Which Williams boat models use the Rotax ACE 1630 engine?
The WILLIAMS Sportjet 435 Sport, 400, 460, and 520 boats, manufactured from 2021 onward. Confirm the installed engine; the exact model is written on the serial number plate.
What are the main differences between naturally aspirated and supercharged Rotax 1630 engines?
Supercharged versions use forced induction to generate more power. This is the function of the supercharger compatibility and maintenance requirements differ. Indeed, a supercharger overhaul, including the reconditioning of the shaft and bearings, is required every 200 operating hours
What engine oil should I use in a Rotax 1630?
Generally, BRP XPS 4T 5W-40 synthetic oil; confirm the specification in your model's owner's manual.
How much oil does a Rotax 1630 engine require?
Total dry capacity / after complete reconditioning: 4.8 US quarts (4.5 L). Capacity during a standard oil change: approximately 3.2 US quarts (3.0 L). Confirm the final level by following the procedure prescribed for your model.
How do I properly check the oil level in a Rotax 1630?
- Start the engine and run it with an appropriate water supply if it is out of the water, or ride briefly to bring the oil up to its normal operating temperature.
- Briefly increase the RPM to approximately 4,000 to 4,500 RPM for about 15 seconds to ensure oil circulation and pickup.
- Immediately stop the engine using the start/stop button or remove the kill switch lanyard.
- Wait about 30 to 60 seconds to allow the oil to drain back into the reservoir / oil pan.
- Top up gradually if necessary.
- Repeat the process if necessary.
Which oil filter is suitable for the Rotax 1630 engine?
Check your original part number; confirm the compatibility of 420956744 with your engine before ordering. Remember to replace the 2 large O-rings and the small O-ring of the filter cover assembly at the same time.
Which spark plugs are used on a Rotax 1630?
As with the Rotax 1630, use compatible NGK DCPR8E spark plugs
. How often should a Rotax 1630 engine be serviced?
First service after break-in: between 10 and 25 hours (oil change and filter replacement, debris check, and system inspection). Regular full service: every 50 hours or once a year. Follow your model's owner's manual if its maintenance schedule differs.
Why won't my Rotax 1630 engine start?
Possible causes include the battery, starting circuit, electrical supply, fuel supply, or ignition faults.
Why does my Rotax 1630 start but lose power when accelerating?
The fuel supply, ignition, air intake, supercharger on supercharged versions, compression, or propulsion system may be to blame.
Why is my Rotax 1630 engine overheating?
Coolant loss, limited cooling flow (sea water), a faulty thermostat, or heat exchanger may be to blame; see our overheating guide.
Why is my Rotax 1630 running unevenly or misfiring?
Spark plugs, coils, injectors, fuel supply, sensors, wiring, or compression may be to blame.
What are the most common problems with the Rotax 1630 engine?
Possible problems include starting difficulties, misfires, power loss, overheating, and electrical faults; causes vary by engine.
How do I read Rotax 1630 fault codes?
Use the display procedure specific to your model or a compatible diagnostic tool; see our fault code guide.
What do Rotax 1630 fault codes mean?
They identify detected faults, not necessarily defective parts; see our Rotax fault code list.
How do I know if a Rotax 1630 fuel pump or injector is defective?
Have a qualified technician check the fuel supply and injectors according to the model's workshop procedure. The values provided above are for a 12 V supply, 2 to 3 seconds of priming, and a minimum pressure of 52 psi for supercharged versions; confirm the applicable specifications before any testing. Do not run removed injectors to spray fuel into the engine compartment without taking all necessary precautions.
How do I identify the correct spare part for my Rotax 1630 engine?
Check the OEM part number, engine version, and model; send us a photo if in doubt.
Where can I buy replacement parts for the Rotax 1630?
Buy genuine parts from a SEADOO or WILLIAMS dealer, or browse our aftermarket parts presented below; confirm compatibility before ordering.