Frequently asked questions
SERVICE & SUPPORT
YANMAR Frequently Asked Questions
General
Choosing YANMAR Marine engines offers several benefits:
- Performance and Efficiency: YANMAR marine engines set the global standard in performance, efficiency, and endurance. They ensure optimal operation for your vessel, making them a top choice for marine applications.
- Reliability and Endurance: Yanmar’s reliable engines are well known to have a low total cost of ownership. Built to withstand the demanding conditions of the sea, these engines provide peace of mind and safety.
- Advanced Technology: Yanmar is the only manufacturer to bring the benefits of common rail technology to smaller vessels, providing 5x Best in Class standards – Clean, Interconnective, Quiet, Powerful, & Fuel Efficient. This innovation enhances engine performance, making them cleaner, quieter, more powerful, and fuel-efficient.
- Extensive Service Network: Yanmar has the largest sales and service network in the marine industry, covering over 130 countries worldwide. This ensures that you have access to support and parts wherever you are.
- Sustainability: Yanmar is the inventor of the modern diesel engine and is continuing to innovate solutions that push the boundaries of marine propulsion into the next century. Meeting the demands of the evolving, modern consumer by providing advanced and sustainable technologies is proudly at the forefront of development at Yanmar Marine International.
Whether you’re looking for an engine for recreational or commercial use, Yanmar’s combination of performance, reliability, and innovation makes it a top choice.
To find information about our recreational and light duty commercial marine engines, please visit the YANMAR Marine International website. Here you will find information about the products and product specifications.
Alternatively, you can contact your nearest YANMAR dealer. Please visit our Network Page to search for your nearest YANMAR dealer.
YANMAR Marine International sells through a network of Distributors and Dealers. Pricing could vary depending on several factors including currency, location, etc. Please visit our Network Page to search for your nearest local dealer to get a quote. You may also contact your local distributor directly who will be able to help you find the best dealer to contact based on your specific needs.
If you are interested in repowering your vessel with a new YANMAR engine, visit our Repower Page online to learn more. We’ve gathered everything you need to know when considering a repower in our handy, downloadable Repower Guide.
Additionally, to discuss your repower project with your local Distributors or Dealers, please visit our Network Page.
Operation Manuals for currently offered engines can be downloaded per model in each online product page. For non current engines, please contact your local dealer or regional distributor.
Visit our Network Page to search for your nearest local distributor or dealer.
YANMAR conveniently provides access to 2-dimensional and 3-dimensional technical drawings in the online product pages.
You can also use our dealer locator – Network Page to search for your nearest local distributor or dealer for further help.
YANMAR Marine International sells engines and parts through a distribution and dealer network. Please visit our Network Page to find your local distributor or dealer.
YANMAR does not advise the use of any fuel additives. The best advice is to keep the tank full to limit condensation and make sure water is drained. Please refer to the engine Operation Manual for details.
Bio-diesel can be used within limits and with precautions. Please refer to the engine Operation Manual for details.
Engines
Oils and coolants vary by engine model and drive/gear models. Refer to the Operation Manual for specific recommendations for your operating conditions or discuss with your local YANMAR dealer. YANMAR offers oil and coolants specifically qualified for our products.
If you are having problems with your engine, we recommend contacting your local dealer for assistance. Please visit our Network Page to search for your nearest local dealer.
Alternatively, you can submit a technical inquiry or search our knowledge base through the YANMAR Marine Support Portal. Learn more about the YANMAR Marine Support Portal.
YANMAR Paint is available from your local dealer. Please visit our Network Page to search for your nearest local dealer.
If needed, a Declaration of Conformity can be found towards the end of your engine’s Operation Manual.
You can find the serial number by looking at the engine information plate. The Engine model information is important to accompany your serial number. Examples of engine model names are: 4JH3, 6LY2, 8LV, etc.
Please visit our Warranty Page online where you can download a copy of our Limited Warranty Handbook to learn all details.
You can easily register your engine in our YANMAR Marine Support Portal. Please visit our Register Your Engine page online to learn more.
Periodic maintenance is important for maximizing performance and extending the life of your engine. Each engine Operation Manual, which can be downloaded from the online product pages, comes with a Periodic Maintenance section. This section includes a suggested maintenance interval schedule: 50 hours, 250 hours, 500 hours, and 750 hours.
Please visit our Network Page to search for your nearest local distributor or dealer.
This depends entirely on the type of maintenance and your individual skill set. YANMAR recommends all service to be done by an authorized YANMAR dealer, as detailed in your Operation Manual’s Maintenance section.
What should I specifically avoid doing maintenance on by myself?
For electronically controlled engines, special equipment is required, which only authorized YANMAR dealers can provide. Even if you are familiar with and are well equipped to perform maintenance on your electronically controlled engine, YANMAR still recommends contacting an authorized dealer because doing this maintenance yourself might void parts of or all of your warranty.
Operation Manuals have seasonal maintenance guidelines and recommended parts, for example to perform proper winterization. Operation Manuals for engines can be downloaded per model in the online product pages. Please also contact one of our authorized YANMAR dealers who can help with seasonal maintenance.
Visit our Network Page to search for your nearest local dealer.
YANMAAR Genuine parts can be purchased from your local authorized YANMAR dealer. Please visit our Network Page to search for your nearest local dealer.
Each engine’s Operation Manual comes with a Maintenance section that you can refer to. To get parts information and a full parts list for your engine, please contact your local dealer. To get parts information and a full parts list for your engine, please contact your local dealer.
Visit our Network Page to search for your nearest local distributor or dealer.
Yes, please visit your local authorized YANMAR dealer who will be able to provide a kit or customize one for your specific needs. Visit our Network Page to search for your nearest local dealer.
Genuine YANMAR marine parts are specially designed for YANMAR marine engines. There are likely other aftermarket parts available for different needs. However, YANMAR cannot recommend or defend the use of non-YANMAR parts. As such, the use of non-YANMAR parts might also void parts of or all of your warranty. Therefore it is important to use only Genuine YANMAR Parts for everlasting reliability and performance.
One of the many benefits of a YANMAR electronically controlled engine is that it can produce alarm or diagnostic troubleshooting codes (DTC) on the YANMAR panel. These codes are identified by sensors in the engine and catch potential issues that could otherwise go unknown, and sometimes occur long before the issue can contribute to an engine failure. This preventive troubleshooting can save your engine/s from costly repairs. Some DTCs can be found in the engine’s Operation Manual’s Troubleshooting section. If you cannot locate the DTC, please contact your local authorized YANMAR dealer.
Visit our Network Page to locate your nearest local dealer.
Electric Propulsion – the YANMAR SDe Electric Saildrive
YANMAR’s new 48V Electric Saildrive series features robust innovative technology and a unique integrated cooling system and controller = Silent, low maintenance and fully sustainable.
YANMAR’s new 48V Electric Saildrive is most suitable for day sailors, catamarans or cruisers up to 40 ft (depending on displacement).
The new YANMAR 48V Electric Saildrive series is perfect for repowering from YANMAR YM engine series.
The range of YANMAR’s electric saildrive depends on the battery capacity and the power setting used. Specific range details can vary, but the system is designed to provide sufficient power for typical day sailing and cruising needs.
You can find more information on the Electric Saildrive series product page.
YANMAR’s Electric Saildrive series uses Lithium-ion (LiFePO4) batteries, which are known for their high energy density, long life, and reliability.
Note: Battery and Propeller are not included in the standard delivery. You can find more information on the Electric Saildrive series product page.
Yes, YANMAR offers three power ratings for the Electric Saildrive:
- 7kW @2700 RPM
- 10kW @2700 RPM
- 15kW @2700 RPM
Note: Battery and Propeller are not included in the standard delivery. You can find more information on the Electric Saildrive series product page.
To repower your sailboat with the YANMAR SDe, please contact your YANMAR dealer. They can provide you with detailed information on the installation process, help you choose the right model for your boat, and guide you through the repowering process.
YANMAR has the largest sales and support network in the marine industry, with more than 2,000 authorized YANMAR distributors and dealers located in over 130 countries. You can enjoy a seamless sailing experience, knowing you are covered no matter where you sail to.
Visit our Network Page to locate your nearest local dealer.
HVO & Alternative Fuel
Hydrotreated vegetable oil (HVO) is a renewable paraffinic (diesel) fuel. It is derived from used cooking oils, residue animal fats from food processing, tall oil, and non-food grade crops.
HVO, a new generation of bio-based diesel, has been treated with hydrogen in order to meet the European EN15940 standard for ‘Paraffinic Diesel Fuel from Hydrotreatment’. This more complex process produces a cleaner fuel, without the drawbacks of traditional, or first generation, biodiesel.
Paraffinic diesel fuels are specified in EN15940 and have higher cetane numbers and lower density than conventional diesel fuels (EN590). HVO and Bio to Liquid (BTL) are renewable paraffinic (diesel) fuels, whereas Gas to Liquid (GTL) is an alternative fossil paraffinic (diesel) fuel. HVO is a clear, colorless, odorless liquid.
Over time bacterial growth can be caused by the hygroscopic properties of FAME (EN590-B7). FAME is the first-generation biofuel and highly hygroscopic, explaining the short shelf life of present EN590-B7 fuel. Due to the better properties, HVO fuel can be kept longer than fuel with FAME content.
The use of renewable (HVO and BTL) fuels will give a substantial decrease (up to 90%) of fossil CO2 emissions. Featuring the low sulfur and aromatics associated with paraffinic fuels, HVO burns more cleanly than first generation biodiesel or mineral diesel.
EN15940 HVO can be used as a direct replacement for fossil diesel in YANMAR’s new and heritage marine sail and powerboat engines, either neat or blended in any proportion. YANMAR allows HVO20, HVO50, HVO100 and also GTL to be blended.
The use of renewable or alternative (diesel) fuels that are in accordance with EN590 or EN15940 is permitted in the following YANMAR engine models:
1GM Series, YM Series, JH Series, 4LH HTP Series, 4LH DTP Series, 4LH STP Series, 6LY Series, 6LF Series, 6LT Series
*Find a complete list of HVO-Approved engines at yanmar.com/marine/technology
The renewable or alternative fuels that are in accordance with EN15940 have lower density and lower calorific value per volume. 6% lower output and 6% higher volumetric consumption than conventional (EN590) diesel fuels are to be anticipated.
After switching to EN15940 HVO, any engine performance loss and higher fuel consumption are not covered by warranty. When renewable or alternative fuels are used that are not in accordance with EN15940, problems as fuel pump seizure or fuel injector seizure may occur due to deterioration of fuel lubricity. This will not becovered by YANMAR’s Limited Warranty Coverage.
It’s always best to check with your local YANMAR dealer for specific guidelines to ensure compliance and maintain warranty coverage. Visit our Network Page to locate your nearest local dealer.
When shifting from conventional EN590 diesel fuel to renewable or alternative (diesel) fuels in accordance with EN590 or EN15940 for existing engines (not new engines), the fuel hoses and all (nitryl) rubber seals must be replaced. Leakage due to no replacement of these parts is not covered by warranty.
It’s always best to check with your local YANMAR dealer for specific guidelines to ensure compliance and maintain warranty coverage. Visit our Network Page to locate your nearest local dealer.
All processes are the same for diesel and HVO fuels.
Tests show that NOx (nitrogen oxides) emissions are similar. There is a reduction in PM (particulate matter) emissions when using HVO fuel compared to diesel and up to a 90% reduction in CO2 emissions.
Engine performance may decrease by 6% due to the lower energy density of HVO fuel. Fuel economy reduces slightly with HVO compared to using diesel.
Availability of HVO is expected to improve, with new legislation to encourage the use of greener fuels. Supply is improving to regulated markets, specifically North America and Europe, and output is predicted to rise in the coming years. It is produced in significant quantities by major fuel producers globally.
The cost of HVO fuel for marine applications varies between countries and whether there are special tax allowances for renewable fuels.

Questions and Support
Learn more by searching our FAQs or find your local dealer or distributor from our global network. Please feel free to contact YANMAR Marine with any non-technical questions by visiting our Contact page below.