At what point does saving money become a project?

We all want to save money. Sure, it is human nature to spend the least, but get the most. However, there is the old idiom about being “Penny wise, but Pound foolish”, often incorrectly attributed to Benjamin Franklin, that often applies when comparing options.

We once had a suspiciously large parts order from a new, unknown customer. When the parts department received the order, they were perplexed: When did we sell an engine to these guys?

They combed through our accounts history and found nothing. What was going on?

It turns out that the customer had been given a GM engine block on the aftermarket (an old GM truck engine) and was trying to marinize it himself to use it on his boat. There are a number of different reasons why this is not a good idea for the average home mechanic, no matter how experienced or no matter how good his mechanical aptitude:

  • Most workshops lack the facilities for proper marinization.
  • You generally cannot use automotive parts in a marine engine, due to corrosion issues.
  • Marinization is a highly technical process. Without experience, the process can quickly become complicated and expensive.
  • Engines perform differently on the water than on land. The power and torque curves are completely different, and on an electronic engine, significant software knowledge is required.
  • Modern emissions requirements are tricky. In some locations, operating a vessel without certified emissions is illegal. It is very difficult to meet emissions requirements without the proper testing facilities.


Most of all….

Marinediesel, as a manufacturer, has certain economies of scale when purchasing components. Quite simply, when you buy thousands of injectors, you pay much less than when you are buying two. Additionally, though it really isn’t a secret, most manufacturers make most of their profit from spare parts and service, rather than from the sale of the engine. That is why there is usually a big difference in markup on spares, but very little difference in price between similar engines (ie. Volvo Penta D6 vs Marinediesel VGT 400).

In the end, he was a little shocked that refurbishing his old engine would end up costing almost as much as a new engine. We finally convinced him that he would spend so much time and money that he really would save very little in the end, and most likely end up spending more. A project, indeed…

Genuine Spare Parts – A difference worth choosing

You will often hear us telling our customer to only use Marinediesel genuine spare parts when performing maintenance on their engines. Though this may seem like merely a way to earn additional profit, there are some very good reasons to only use spares provided by either Marinediesel or our official distributors:

  1. Marinediesel engines are designed, tested, and certified with parts that are tested by us specifically for your engine model. We have no control over the production standards, quality, or compatability of aftermarket parts. Though the part may work to immediately fix a problem, it may not be 100% be compatible with your engine.
  2. On marine engines, all genuine spare parts are marine grade spares. Aftermarket parts may not be suitable to the marine environment.
  3. Only Marinediesel Genuine Spare Parts carry a one year warranty from Marinediesel.
  4. The use of improper spare parts or replacement parts will impact your warranty. Marinediesel’s warranty is issued with the expectation that parts either manufactured by us or provided by us will be covered under the warranty. In other words, using an improper part may void your warranty.

This article is not intended in any way as a comment on the quality of aftermarket spare parts. Indeed, in most cases aftermarket parts will be adequate. However, in order to ensure a long, proper service life of your engine, and compliance with your performance standards, only Marinediesel Genuine Spare Parts should be used for your maintenance and repairs.

MarineDiesel Dealer Profile – JMP Marine Korea


Today’s article is about our distributor in the Republic of Korea, JMP Marine. MarineDiesel has long worked with JMP in Korea, and we are proud to have such a technically proficient partner working with us there.

The Korean market is complex, with rigid emissions regulations and a well-developed shipbuilding industry. JMP Marine is well-positioned, with their office in Busan, in the center of the Korean maritime industry.

JMP has been working with numerous engine and repair companies manufacturing whole pumps or parts under the direction of engineers looking for the quality expected of the pumps to be used on the engines they manufacture or repair.

JMP offers their experience in the R&D department to bring out new pumps for engine manufacturers. JMP offers a niche market in the parts supply for older pumps. They include Shafts, Cams, Mechanical Seals, Bearings, Gaskets, O-Rings, Cover Plates etc.

In addition to being a manufacturer of innovative impellers and pumps, they represent MarineDiesel and several other engine brands in Korea, including Seasall. They are fully factory trained and maintain complete spare parts in-country.

If you are interested in a quote for your project, please contact JMP Marine:

JMP Marine

74-7 Samrack-dong, Sasang-gu, Busan
Korea 617-070
Phone: +82 513027337



Always check your serial number


Engines occasionally have mechanical problems. They all do. Often, when customers or distributors contact MarineDiesel for service or spare parts, the first thing we will ask, even before the problem, is for the engine’s serial number.

The serial number of the engine is always located on a metal tag on middle of the starboard  side of the engine (right side on non-marine or industrial engines). The serial number will be in the following format MD-XXX######, with six digits after the “XXX”.

Why do we ask for the serial number? Several reasons:

  1. Often, there have been service advisories, component upgrades, or changes to the design of the engine that were made after it was built. The serial number is logged at the time the engine is manufactured, and we instantly know what, if any, changes were made since that time.
  2. Warranty issues always require a serial number. If we have warranty repairs, we need to track them based on the date of manufacture.
  3. We need to verify the specific engine model. Though perhaps 80% of the components are compatible between engine models, around 20% are non-compatible.
  4. We need to check the version of the ECU software and whether any customizations were made.





Maintenance Tip of the Week – Solenoids 01/26/2015



Maintenance Tip of the Week – Solenoids

Spare solenoids for fuel or air shutdown should always be a part of your onboard spares list. They are often the first items to fail when problems occur and are easily damaged.


Why use MarineDiesel Genuine Spare Parts?



Spare parts can get expensive at times. MarineDiesel understands this fact, and though we build our entire product line of engines to be as reliable as possible, any engine will eventually require a supply of spare parts. This is one reason why we are so stringent in our requirements for our distributors.

It can be tempting to use substitute or aftermarket spare parts in order to save money. From a sheer technical perspective, as long as a part meets the technical specification as defined in your manual, those parts should suffice. However, MarineDiesel does not recommend substitution as a solution except in unusual circumstances. The reason why?

Only MarineDiesel Genuine Spare Parts have been thoroughly tested by us in our test cells and factory for both compatibility and reliability. Our parts go through the same rigorous inspection, testing, and quality control measures as our engines before leaving the factory, and are guaranteed to be acceptable replacements. We cannot make this guarantee with cheap replacement or aftermarket parts.

We often sell spares packages with new engines, and we can customize or propose a spares package with your quote, shipped with your new engines. This is particularly useful if engines will be used in remote geographical locations.

Contact us or your local MarineDiesel distributore today for a custom package.



Fuel Injectors – OEM or Aftermarket?



Perhaps the most critical component of your diesel engine is the fuel injectors. These parts are, admittedly, expensive, and not particularly easy to replace.

Especially when operated in areas with dirty or bad fuel, clogged injectors create many problems with your engine, not least of which is loss of performance. Though the standard sizes of injectors are the same per engine block, the materials from which they are made is not standardized. For marine use, fuel injectors are made to withstand corrosion and the marine climate. This is where you can run into problems when replacing injectors with cheaper, aftermarket parts. Since our engines use a Duramax block, and these are standardized bv GM for automotive and truck use, there are many aftermarket injector options on the market.

Should you use these?

Our answer, generally, is “No”. MarineDiesel genuine spare parts (“GSP”) are designed for the specific use where the engines will be used. On marine engines, these fuel injectors will resist corrosion and give a long life cycle. Cheaper aftermarket parts offer no such guarantees.

Additionally, diagnosing injector problems is technical, normally requiring dealer service unless the customer has the facilities necessary to diagnose the problem. The fuel in common rail engines is under tremendous pressure, and specialized testing facilities are required to determine if an injector is faulty.




Maintenance Tip of the Week – OEM Parts 08/11/2014



Maintenance Tip of the Week


Always use OEM spare parts when replacing engine components. Though aftermarket parts are often much cheaper, they are often cheaply manufactured and do not undergo the rigorous testing and quality control that OEM parts undergo.


Maintenance Tip of the Week – Rust 07/14/2014



Maintenance Tip of the Week


The acid in regular household vinegar can dissolve rust on spare parts. (Though we recommend replacement with new if too rusty).


Ask Professor Diesel – 06/09/2014


This week’s question comes from Pablo in Spain:


Professor Diesel:

My local dealer offered me an extended service contract for my engines. Why should I take this? Can’t I order from you directly?



We will always sell spare parts to customers. However, it is worth noting that modern engines are much more complex than the old, workhorse diesels of yesteryear. Emissions and fuel regulations have made servicing engines a much more difficult task than it used to be. MarineDiesel certifies our dealers and distributors to service and maintain our engines. They have rigorous standards relating to inventory, service capability, training, and ongoing education to which they must adhere. They are familiar with our engines and know what diagnostics to perform in order to resolve problems. We have learned through years of experience that a well-trained service network is critical.

In terms of cost, spares cost roughly the same whether ordered from us, or purchased locally from our dealers. There are many reasons for this, largely economies of scale, but we know that our dealers offer fair pricing and excellent service.

We will always suggest that customers accept service offers from our network: They always save money and hassle over the long term.

If you have a question for Professor Diesel, please fill in the form below:

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