WILLIAMS 435 SportJet Sport
(Rotax ACE 1630 Engine)
Technical guide, maintenance, and spare parts
The Williams SportJet 435 Sport described in this article is equipped with the 170 HP BRP Rotax ACE 1630 engine. This configuration must be distinguished from the 435 Sport with the 150 HP 1503 engine and the Standard model with the 90 HP ACE 903 engine.
Its 1,630 cc, four-stroke, three-cylinder engine belongs to the generation that succeeded the Rotax 1503 in the range. Our Rotax guide lists applications for the Williams 435 Sport, 400, 460, and 520 from 2021 onwards; however, always confirm the actual engine installed using its plate and serial number.
At Rotax Tender Parts, we offer maintenance and replacement parts: filters, spark plugs, electrical components, sensors, fuel system parts, gaskets, and cylinder head components. Some part numbers are common to several engine types, but the designation "SportJet 435" or "Rotax 1630" alone does not guarantee fitment. The selection below distinguishes the necessary part numbers and checks.
Find parts for your WILLIAMS SportJet 435 Sport – Rotax 1630
- Engine parts
- Fuel supply system
- Ignition
- Sensors
- Electrical parts
- Cooling
- Oil and filters
- Gaskets and sealing
- Jet pump unit parts
- Others
The different versions of the Williams SportJet 435
This article is dedicated to the SportJet 435 Sport with the 170 HP Rotax ACE 1630 engine. The three configurations below help distinguish the engine types, without replacing the need to verify the engine plate.
- SportJet 435 Sport – Rotax 1630 (described in this article)
- SportJet 435 Sport – Rotax 1503
- SportJet 435 Standard – Rotax ACE 903
SportJet 435 Sport – Rotax 1630 (described in this article)
The version studied is equipped with the 170 HP BRP Rotax ACE 1630, a three-cylinder, four-stroke engine. Identify this configuration before selecting parts: products reserved for the 230 or 300 HP supercharged versions are not compatible with the 170 HP version simply because they share the same displacement.
See our Rotax 1630 engine guide.
SportJet 435 Sport – Rotax 1503
The other generation of the SportJet 435 Sport described in our resources uses the 150 HP BRP Rotax 1503 4-TEC, a 1,494 cc, four-stroke, three-cylinder engine. The characteristics and specific parts of this version should not be automatically applied to the 1630.
See our guide for the Williams 435 Sport with Rotax 1503 engine.
SportJet 435 Standard – Rotax ACE 903
The Standard version is equipped with the 90 HP BRP Rotax ACE 903. This three-cylinder, four-stroke engine is also used on the TurboJet 285 and 325, as well as the SportJet 345 and 395 described in our guides.
Find its characteristics and parts in our article on the Williams 435 Standard with Rotax ACE 903 engine.
How to know which SportJet 435 version you have?
Check the manufacturing year, the engine model on the plate or certificate of conformity, the horsepower, and the serial number of the tender or engine. Photos can help with identification but do not replace checking the engine. Two visually similar SportJet 435s may use different mechanical parts.
Technical characteristics of the Williams SportJet 435 Sport – Rotax 1630
- Model: Williams SportJet 435 Sport.
- Engine: BRP Rotax ACE 1630.
- Architecture: three-cylinder, four-stroke.
- Displacement: 1,630 cc.
- Power of the described configuration: 170 HP.
- Propulsion: Jet drive.
- Dimensions, weight, capacity, tank, and maximum speed: to be confirmed in the manufacturer's specification sheet for the relevant model year.
The 480 kg and 84 km/h values listed in the 1503 article are not included as characteristics of the 1630. Use the data for your specific tender and its equipment for storage, handling, load, and performance.
Maintenance schedule – Williams SportJet 435 Sport / Rotax 1630
An initial "break-in" service must be performed between 10 and 25 hours (oil change and oil filter replacement, check of hoses, clamps, and general inspection).
Afterward, the Williams maintenance schedule is based mainly on three intervals: 50 hours or 1 year, 100 hours or 1 year, and 200 hours or 2 years. For operations directly related to the Rotax 1630 engine, also consult the corresponding engine manual. A dash indicates that no operation is specified in that cell of the provided table, not that maintenance is waived.
| Item | 50 h / 1 year | 100 h / 1 year | 200 h / 2 years |
|---|---|---|---|
| Engine oil and filter | Replace | Replace | — |
| Rubber engine mounts | Inspect | Inspect | — |
| Engine anti-corrosion protection | Lubricate regularly* | Lubricate regularly* | — |
| PTO sleeve / seal | — | — | Replace** |
| Exhaust system | Inspect | Inspect / clean | — |
| Exhaust flushing | Clean regularly*** | Clean regularly*** | — |
| Cooling hoses and fixings | Inspect | Inspect | — |
| Coolant | Inspect | Inspect | Replace |
| Throttle body | Inspect | Inspect | — |
| Fuel circuit and lines | Inspect | Inspect | — |
| Engine fault codes | Inspect | Inspect | — |
| Air filter | Inspect / replace if necessary | — | — |
| Spark plugs | Inspect | Inspect | Replace |
| Ignition coils | Inspect | Inspect | Inspect |
| Electrical connections | Inspect | Inspect | Inspect |
| Engine kill switch | Inspect | Inspect | Inspect |
| Steering cable and linkage | Inspect | Inspect | — |
| Steering nozzle bushings | Inspect | Inspect | — |
| Carbon ring / drive shaft bellows | Inspect | Inspect | — |
| Propulsion control and cables | Inspect | Inspect | — |
| Reverse bucket | Lubricate | Lubricate | — |
| Jet pump shaft / splines and PTO | Inspect / lubricate | — | — |
| Shaft seal, sleeve and O-ring | Inspect | — | Replace |
| Impeller and wear ring clearance | Inspect | Inspect | — |
| Sacrificial anode | Regular check**** | Regular check**** | Regular check**** |
| Intake grate / plate | Inspect | — | — |
* In saltwater use, apply anti-corrosion protection to metal components in the engine compartment every 10 operating hours.
** The PTO sleeve and seal must be replaced at 200 hours, regardless of the number of years.
*** The exhaust system must be flushed daily after use in saltwater or dirty water.
**** The sacrificial anode must be checked every month, and every two weeks in saltwater. It must be replaced when necessary.
Important points for saltwater use
A SportJet used as a yacht tender is exposed to seawater. Corrosion prevention is therefore particularly important. After use, pay special attention to the following, following the manufacturer's procedures:
- system flushing;
- jet pump unit flushing;
- anode check;
- engine compartment cleaning;
- anti-corrosion treatment for metal components;
- electrical connection check;
- impeller and intake grate check.
See our engine flushing guide as a supplement to the WILLIAMS and Rotax manual specific to your configuration.
Common parts for the WILLIAMS SportJet 435 Sport – Rotax 1630
For this 170 HP configuration, this selection presents compatible parts for the Rotax 1630 engine powering the Williams 435 SportJet. OEM references identify the parts being replaced; they do not automatically designate genuine parts.
The iNR connector only concerns tenders equipped with this option. For cylinder head parts, have the valve assembly, grooves, cotters, springs, and retainers validated by a professional.
Common issues with the WILLIAMS SportJet 435 Sport – Rotax 1630
The following symptoms can have multiple causes. These points guide checks but do not replace a diagnosis or automatically justify replacing a part. Work on fuel systems, electrical circuits, and moving parts must be carried out safely, in accordance with the manual, and by a professional when necessary. (FMT)
- Engine does not start: battery, electrical connections, battery switch, safety lanyard, fuses, relays, fuel supply, spark plugs, ignition coils, or sensors. A battery capable of powering accessories may not provide sufficient voltage during cranking.
- Engine misfire: methodically check the ignition, fuel supply, sensors, connections, and compression before replacing a part.
- Lack of power: spark plugs, ignition coils, fuel supply, injectors, sensors, ECU faults, cooling, or the propulsion unit may be involved. Diagnostics and supercharging parts from other 1630 versions must not be automatically transposed to the 170 HP engine.
- Fault code display: the code points to a detected anomaly without necessarily identifying a faulty part. Check the fault and the intended checks for the installed engine.
- Engine overheating: check water supply, cooling, hoses, obstructions, and exhaust according to documentation. Stop the engine in case of a persistent alert. Consult our article dedicated to engine overheating.
- Engine runs but thrust decreases: an obstruction of the water intake, debris, or a damaged internal impeller or wear ring may be the cause. Stop the engine and prevent any restart before any inspection; never attempt to clear the water intake while the engine is running.
Consult our Rotax fault code guide to direct your checks. (FMT)
How to identify the right part for your SportJet 435 Sport 1630?
Send us a clear photo, the visible OEM reference, the model, the year, and the engine serial number. Specify the Rotax ACE 1630 170 HP engine and the presence of the iNR option for the relevant components. Do not rely solely on the SportJet 435 designation.
Identify my part from a photo.
SportJet 435 Sport Rotax 1630 or Standard Rotax ACE 903?
This comparison distinguishes the Sport version equipped with the 1630 170 HP from the Standard ACE 903 90 HP described in our guide.
| Characteristic | 435 Sport – Rotax ACE 1630 | 435 Standard – Rotax ACE 903 |
|---|---|---|
| Engine | BRP Rotax ACE 1630 | BRP Rotax ACE 903 |
| Architecture | 3 cylinders, 4-stroke | 3 cylinders, 4-stroke |
| Displacement | 1,630 cm³ | 899 cm³ |
| Power | 170 HP | 90 HP |
| Dry weight | To be confirmed based on model year and equipment | 446 kg in the described configuration |
| Advertised max speed | To be confirmed based on model year and configuration | 64 km/h (40 mph) |
| Dimensions and capacity | Consult the 1630 model year sheet | 4.35 × 1.94 m; 7 people |
| Fuel tank | To be confirmed in the tender documentation | 60 liters |
The Sport 1630 develops 170 HP versus 90 HP for the Standard presented. This difference alone does not allow for a deduction of speed, payload, or fuel consumption: check the characteristics of each tender. Engine and propulsion references must be checked separately. Find the Williams SportJet 435 Standard guide for this other configuration.
WILLIAMS 435 SportJet (Rotax 1630 – 170 hp): Frequently Asked Questions - FAQ
-
What engine powers the Williams SportJet 435 Sport?
The version described in this article appeared in 2021 and is equipped with the BRP Rotax ACE 1630 170 hp, a 1,630 cm³ three-cylinder four-stroke engine. It is distinguished from the Sport generation with the 1503 150 hp engine and the Standard ACE 903 90 hp engine.
-
What is the difference between the SportJet 435 Standard and the SportJet 435 Sport 1630?
The SportJet 435 Standard presented in our guide uses the Rotax ACE 903 899 cm³ 90 hp. The Sport version described here uses the Rotax ACE 1630 1,630 cm³ 170 hp. Their engine parts and propulsion components are different.
-
What is the maximum speed of the SportJet 435 Sport 1630 170 hp?
The maximum speed must be verified in the manufacturer's specification sheet for the specific model year and configuration. The 84 km/h indicated for the 1503 150 hp version is not confirmed data for the 1630 170 hp version. Load, condition of the propulsion unit, and navigation conditions also influence performance.
-
What is the displacement of the Rotax ACE 1630?
The Rotax ACE 1630 described has a displacement of 1,630 cm³, with three cylinders and a four-stroke cycle. Its power in the configuration of this article is 170 hp.
-
How many people can a SportJet 435 Sport 1630 carry?
The Williams SportJet 435 described can carry up to 7 people. Observe your tender's capacity and load limits.
-
What is the fuel tank capacity of the SportJet 435 Sport 1630?
The 60-liter capacity mentioned in our other guides is not repeated here as confirmed data for your 1630 configuration.
-
What is the weight of the SportJet 435 Sport 1630?
The dry weight must be confirmed in the manufacturer's sheet for the relevant model year, along with installed equipment. The 480 kg indicated in our 1503 article is not a verified value for the 1630. For lifting and storage, also take into account fuel, onboard gear, and installation limits.
-
Is the SportJet 435 Sport 1630 170 hp equipped with a supercharger?
No. The Rotax ACE 1630 170 hp is an atmospheric (naturally aspirated) version. Superchargers and parts reserved for supercharged versions of the 1630 family must not be selected for this engine based solely on the displacement criteria.
-
Which spark plugs should I use for a SportJet 435 Rotax 1630 170 hp?
The manufacturer recommends NGK DCPR8E spark plugs. Our compatible DCPR8E spark plug is also a very good alternative. Do not confuse it with the CR8EB presented for the Standard ACE 903.
-
When should I perform an oil change for the Rotax 1630?
WILLIAMS schedules a first service after break-in between 10 and 25 hours, then replacement of the engine oil and filter at 50 hours or 1 year, and thereafter every 100 hours or 1 year. Verify the applicability of these deadlines in the WILLIAMS and Rotax manuals specifically corresponding to your 1630 170 hp and its model year. The maintenance table above details the other operations.
-
When should I replace the spark plugs of the Rotax 1630?
The table provided foresees their inspection at 50-hour and 100-hour intervals, and their replacement at 200 hours or 2 years. Confirm these deadlines in the manual applicable to your Rotax ACE 1630 170 hp engine; an ignition fault may require an earlier check.
-
Should I flush the SportJet 435 after use at sea?
Yes. Flush after use in saltwater or dirty water, strictly following the WILLIAMS and Rotax procedure applicable to the 1630 170 hp. Corrosion protection is particularly important in a marine environment. Our flushing guide complements the manual, but does not replace it.
-
Why is my 170 hp Rotax 1630 SportJet 435 lacking power?
A loss of power may notably result from the following elements:
- spark plugs or ignition coils;
- fuel supply;
- injectors;
- engine sensor;
- fault logged in the ECU;
- intake grate obstruction;
- jet pump unit or wear ring;
- cooling issue.
This 170 hp version is naturally aspirated: supercharger troubleshooting is not applicable. Reading the Rotax fault codes and a methodical diagnostic are recommended before replacing any parts. Stop the engine and prevent any restart before inspecting the water intake or the propulsion unit. (FMT)
-
Where can I find parts for a Williams SportJet 435 Rotax 1630?
Rotax Tender Parts offers maintenance parts and components whose applications are specified in the product descriptions. Browse the table in this article and our Rotax parts catalog, then verify the OEM reference, model year, and 170 hp Rotax ACE 1630 configuration. A part listed for a 300 hp 1630 or for a SportJet 400 or 520 is not automatically compatible with your 435. If you do not know the reference, send us a photo, the year, and engine information via Identify your part.
0 comments