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 BRP Rotax ACE 1630 170 HP engine. This configuration should be distinguished from the 435 Sport with the 150 HP 1503 engine and the Standard with the 90 HP ACE 903 engine.
Its 1,630 cm³ four-stroke three-cylinder engine belongs to the generation that succeeded the Rotax 1503 in the range. Our Rotax guide lists the Williams 435 Sport, 400, 460 and 520 applications from 2021; however, confirm the actual engine installed with its plate and serial number.
At Rotax Tender Parts, we offer maintenance and replacement parts: filters, spark plugs, electrical components, sensors, fuel system, gaskets and cylinder head parts. Some references are common to several engines, but the designation "SportJet 435" or "Rotax 1630" alone does not guarantee fitment. The selection below distinguishes the references and the necessary checks.
Find the parts for your WILLIAMS SportJet 435 Sport – Rotax 1630
- Engine parts
- Fuel system
- Ignition
- Sensors
- Electrical parts
- Cooling
- Oil and filters
- Gaskets and seals
- Impeller block parts
- Other
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 allow you to distinguish the engines, without replacing the verification of 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 BRP Rotax ACE 1630 of 170 HP, three cylinders and four strokes. Identify this configuration before selecting the parts: products reserved for the supercharged 230 or 300 HP versions do not become compatible with the 170 HP simply due to the common 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 BRP Rotax 1503 4-TEC of 150 HP, a 1,494 cm³ four-stroke three-cylinder engine. The characteristics and specific parts of this version should not be automatically transferred to the 1630.
See our Williams 435 Sport with Rotax 1503 engine guide.
SportJet 435 Standard – Rotax ACE 903
The Standard version is equipped with the BRP Rotax ACE 903 of 90 HP. 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 version of SportJet 435 you own?
Check the year of manufacture, the engine model on the plate or the certificate of conformity, the power and the serial number of the tender or the engine. Photos can help identify, but do not replace engine identification. Two SportJet 435s of similar appearance 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 cylinders, four strokes.
- Displacement: 1,630 cm³.
- Power of the described configuration: 170 HP.
- Propulsion: hydrojet.
- Dimensions, weight, capacity, tank and maximum speed: to be confirmed in the manufacturer's sheet of the year concerned.
The values of 480 kg and 84 km/h appearing in the 1503 article are not carried over as characteristics of the 1630. Use the data of your tender and its equipment for storage, handling, loading and performance.
Maintenance table – Williams SportJet 435 Sport / Rotax 1630
An initial revision called "after break-in" is to be carried out between 10 and 25 hours (oil change and oil filter replacement, hose checks, clamp checks and general inspection).
Then, the Williams maintenance program is based mainly on three intervals: 50 hours or 1 year, 100 hours or 1 year, then 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 indicated in the box provided, and not a general exemption from maintenance.
| 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* | — |
| Drive shaft sleeve / joint seal | — | — | Replace** |
| Exhaust system | Inspect | Inspect / clean | — |
| Exhaust flush | Clean regularly*** | Clean regularly*** | — |
| Cooling hoses and fasteners | 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 stop switch | Inspect | Inspect | Inspect |
| Steering cable and connection | Inspect | Inspect | — |
| Steering nozzle rings | Inspect | Inspect | — |
| Carbon ring / shaft boot | Inspect | Inspect | — |
| Propulsion control and cables | Inspect | Inspect | — |
| Reverse bucket / rear door | Lubricate | Lubricate | — |
| Shaft / spline of impeller and PTO | Inspect / lubricate | — | — |
| Shaft seal, sleeve and O-ring | Inspect | — | Replace |
| Impeller and wear ring set | Inspect | Inspect | — |
| Sacrificial anode | Regular check**** | Regular check**** | Regular check**** |
| Intake screen / plate | Inspect | — | — |
* When used in salt water, anti-corrosion protection of the metal components of the engine compartment every 10 hours of use.
** The sleeve and drive shaft seal are to be replaced at 200 hours, regardless of the number of years.
*** The exhaust system must be flushed daily after use in salt water or dirty water.
**** The sacrificial anode must be checked every month, and every two weeks in salt water. It must be replaced when necessary.
Important points for use in salt water
A SportJet used as a yacht tender is exposed to sea water. Corrosion prevention is therefore particularly important. After use, pay special attention to the following elements, according to the manufacturer's procedures:
- flushing the circuit;
- flushing the propulsion block;
- anode check;
- cleaning the engine compartment;
- anti-corrosion treatment of metal components;
- electrical connection check;
- impeller and intake screen check.
Consult our engine flushing guide in addition to the WILLIAMS and Rotax manual specific to your configuration.
Common parts of the WILLIAMS SportJet 435 Sport – Rotax 1630
For this 170 HP configuration, this selection presents compatible parts for the Rotax 1630 equipping the Williams 435 SportJet. OEM references identify the replaced parts; they do not automatically designate original parts. Click on a "Buy" thumbnail to add one unit of the product to the cart and access the cart. When the batch or version requires a choice, the "Choose the version" thumbnail opens the product sheet. The names and references keep their links to the sheets.
The iNR connector concerns only the tenders equipped with this option. For cylinder head parts, have the set of valves, ports, keys, springs and valve seats validated by a professional.
Common Problems with the WILLIAMS SportJet 435 Sport – Rotax 1630
The following symptoms can have several causes. These clues guide inspections without replacing a diagnosis or automatically justifying the replacement of a part. Work on fuel, electrical circuits and moving parts must be carried out safely, according to the manual and by a professional when necessary. (FMT)
- The engine does not start: battery, electrical connections, battery cut-off switch, kill cord, fuses, relays, fuel supply, spark plugs, coils or sensors. A battery capable of powering accessories may not provide sufficient voltage during starting.
- Engine misfires: methodically check the ignition, fuel supply, sensors, connections and compression before replacing a part.
- Lack of power: spark plugs, coils, fuel supply, injectors, sensors, ECU fault, cooling or propulsion block may be affected. Diagnostics and supercharger parts from other 1630 versions should not be automatically applied to the 170 HP.
- Fault code displayed: the code points to a detected anomaly without necessarily identifying a defective part. Check the fault and the inspections provided for the installed engine.
- The engine overheats: check the water supply, cooling, hoses, obstructions and exhaust according to the documentation. Stop the engine in case of a persistent alert. See our article on engine overheating.
- The engine runs but thrust decreases: a water intake obstruction, debris, an internal propeller or a damaged wear ring may be the cause. Stop the engine and prevent any restart before inspection; never attempt to clear the engine water intake while the engine is running.
See our Rotax fault code guide to guide inspections. (FMT)
How to identify the right part for your SportJet 435 Sport 1630?
Send us a clear photo, the visible OEM reference, the model, year and engine serial number. Specify the 170 HP Rotax ACE 1630 engine and the presence of the iNR option for the components concerned. 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 170 HP 1630 and the Standard ACE 903 described in our guide.
| Feature | 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 according to year and equipment | 446 kg in the described configuration |
| Announced maximum speed | To be confirmed according to year and configuration | 64 km/h (40 mph) |
| Dimensions and capacity | See the 1630 year sheet | 4.35 × 1.94 m; 7 people |
| Fuel tank | To be confirmed in the tender documentation | 60 liters |
The Sport 1630 produces 170 HP compared to 90 HP for the Standard presented. This difference does not allow, on its own, to deduce a speed, payload or consumption: see the specifications 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
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What engine equips the Williams SportJet 435 Sport?
The version described in this article appeared in 2021 and is equipped with the BRP Rotax ACE 1630 of 170 hp, a three-cylinder four-stroke engine of 1,630 cm³. It differs from the Sport generation with the 150 HP 1503 engine and the Standard ACE 903 of 90 HP.
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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 of 899 cm³ and 90 HP. The Sport version described here uses the Rotax ACE 1630 of 1,630 cm³ and 170 hp. Their engine parts and propulsion components are different.
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What is the maximum speed of the SportJet 435 Sport 1630 of 170 hp?
The maximum speed must be checked in the manufacturer sheet of the concerned year and configuration. The 84 km/h indicated for the 150 HP 1503 version is not confirmed data for the 170 hp 1630. The load, the condition of the propulsion block and the navigation conditions also influence performance.
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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.
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How many people can a SportJet 435 Sport 1630 carry?
The Williams SportJet 435 described can accommodate up to 7 people. Respect the capacity and load limits of your tender.
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What is the capacity of the SportJet 435 Sport 1630 tank?
The capacity of 60 liters appearing in other versions of our guides is not included here as confirmed data for your 1630 configuration.
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What is the weight of the SportJet 435 Sport 1630?
The dry weight must be confirmed in the manufacturer sheet of the concerned year, with the 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 the fuel, the onboard equipment and the installation limits.
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Is the SportJet 435 Sport 1630 of 170 hp equipped with a supercharger?
No. The Rotax ACE 1630 of 170 hp is a naturally aspirated version. The superchargers and parts reserved for the supercharged versions of the 1630 family should not be selected for this engine based solely on displacement.
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What spark plugs to use on a SportJet 435 Rotax 1630 of 170 hp?
The manufacturer recommends the NGK DCPR8E spark plugs. Our DCPR8E compatible adaptable spark plug is also a very good alternative. Do not confuse it with the CR8EB presented for the Standard ACE 903.
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When to perform the Rotax 1630 oil change?
WILLIAMS provides for a first revision after break-in between 10 and 25 hours, then the replacement of the engine oil and the filter at 50 hours or 1 year, then every 100 hours or 1 year. Check the applicability of these deadlines in the WILLIAMS and Rotax manuals corresponding precisely to your 170 hp 1630 and its year. The maintenance table above details the other operations.
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When to replace the Rotax 1630 spark plugs?
The presented table provides for their inspection at the deadlines of 50 hours and 100 hours, then their replacement at 200 hours or 2 years. Confirm these deadlines in the manual applicable to your Rotax ACE 1630 of 170 hp; an ignition fault may require an earlier check.
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Should the SportJet 435 be rinsed after use at sea?
Yes. Perform the rinsing after use in salt water or dirty water, strictly respecting the WILLIAMS and Rotax procedure applicable to the 170 hp 1630. Corrosion protection is particularly important in a marine environment. Our rinsing guide complements the manual, without replacing it.
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Why does my SportJet 435 Rotax 1630 of 170 hp lack power?
A loss of power can notably come from the following elements:
- spark plugs or coils;
- fuel supply;
- injectors;
- engine sensor;
- fault recorded in the ECU;
- water intake obstruction;
- turbine block or wear ring;
- cooling problem.
This 170 hp version is naturally aspirated: a supercharger fault search is not applicable to it. Reading the Rotax fault codes and a methodical diagnosis are recommended before replacing parts. Stop the engine and prevent any restart before inspecting the water intake or the propulsion block. (FMT)
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Where can I find parts for a Williams SportJet 435 Rotax 1630?
Rotax Tender Parts offers maintenance parts and components with their applications specified in the product listings. Browse the table in this article and our Rotax parts catalog, then check the OEM part number, 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 part number, send us a photo, the year, and the engine information via Identify your part.
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