YANMAR ENGINE MOUNT REPLACEMENT MARINE ENGINE YANMAR 2GM20

Vessel: GibSea 282 -1987

2  ELLEBOGEN 75 (Ref. 128270-08341) and 2 ELLEBOGEN 100 (Ref. 128377-08351)

The main mission of a boat’s engine mounts is to assure the engine seat by isolating the vibrations generated by the engine itself and absorb any shock and vibration when the ship is  sailing.

In addition to the noise and little comfort on board, the vibrations generate a wear on all  boat bindings, going from  the screws of the furniture through the electrical system to the steering and rudder systems.

What happens if I do not change the engine mounts on the boat?

The use and years in service of flexible marine engine mounts damage the anti-vibration properties of the silentblocks. This happens in all engine types, including Yanmar or other brands of sailboats or yacht engines.  Not replacing the engine mounts can cause damage to the marine engine itself, twist the propulsion shaft, cause inconvenience to passengers, and potentially be a flotation safety risk if the engine is not properly fixed to the vessel.

Can the replacement of the marine mounts be done at an affordable price?

Without being a professional mechanic, you can change the engine supports of the boat. With the correct tools, you only need to follow several steps.  There is a community of ellebogen marine media users, who share their experiences and ways to change the supports. In this community there are explanatory videos about how you can do the replacement of these supports when the sailboat or boat has an engine compartment of small or  large dimensions.

Case study: Gibsea 282-1987. Yanmar 2GM20 engine

We will explain a real case of an owner of a sailboat GibSea 282 from 1987. The engine is a  Yanmar  two-cylinder reference  Yanmar  2GM20. It is a boat of 8 meters in length and 3.1m of beam made of monolithic polyester with a displacement of 850Kg.

It is a boat that well maintained and properly stowed can accommodate 4 people.

Below the steps for the installation are described:

Before start, you should know the engine reference. This reference is on a plate attached to the engine cylinder head cover.

Figure 1: Registration of the Yanmar 2GM20 model.

Having this information, we must identify the reference of each support in the Yanmar engine.  Generally speaking, they have a number that can be 75, 100, 150 or 200. It is engraved on rubber.

Then, buy the equivalent Ellebogen marine mounts that contain the same number as the piece to be exchanged, as it is shown in the illustrations below:

In case you do not know what engine mounts correspond to the Yanmar engine, you can  enter the reference of the  Yanmar engine in the section “choose your engine” in the selector of our website: https://www.ellebogen.com/tienda/?filters=product_tag[220] .

It automatically gives the answer of which Ellebogen marine mount are suitable for the chosen engine. The following Yanmar engine references can be chosen:   3YM20, 3YM30, 2GM20, 2GM20F, 3GM30, 3GM30F, 3JH2BE, 3JH2TBE, 3JH2TE, 4JH2BE, 4JH2TBE, 4JH2HTE, 4JH2DTE, 4JH2UTBE, 4JH2UTE.

Figure 4: Section "Choose your engine".
Figure 4: Section “Choose your engine”.

For help, the www.ellebogen.com website provides you a chat that can help you at all times to answer any questions that you may have.

We continue:

As long as the drive shaft is well aligned, it is convenient to ensure that it can not move. For this, we can place, for example, a wooden board under the shaft, and we proceed to release the connection between the shaft and the transmission.

Figure 5: Secure position and release the shaft..

Once this step has been done, we can start replacing the flexible engine mounts. In this case the owner of the Gibsea  282 has decided to place an anchored hoist on a board above the cab to raise its engine.

Figure 6: Necessity sharpens ingenuity.

With the engine secured and ready to be raised, the fastenings of the marine engine mounts have to be loosened, so that the marine engine is elevated and the flexible supports of the boat can be easily removed.

 

Figure 9: Release the fast attaches from the marine supports

With all bracket fasteners released, it is needed to raise the motor and replace the old supports with the new ones, one by one, looking at the references of the rubber. It is convenient that each new support has the leveling “H” at the same height as the old support. With this step, we ensure that the shaft remains well aligned.

 

Figure 10: The replaced and new media must have the same H dimension.

Once the four marine engine mounts have been replaced, the engine must be lowered, and it is advisable to leave it at rest for 48 hours so that the supports can perform their main creep/settlement.

 

Figure 11: After 48h the alignment process can begin.

With the engine already in place, we present the two driveshaft discs and proceed to perform the alignment. It is necessary to level the anti-vibration mounts, adjusting the height of the support nut, so that the discs of the driveshaft be in parallel.


 

Figure 12: Avoid a leveling higher than 7mm.

The leveling between the base nut and the fixing nut should not exceed more than 3mm. Since the propulsion force of the engine can generate a moment on the height adjusters and this can make it shear by fatigue.

If a higher elevation is needed, it can be achieved by placing a metal plate at the bottom, but in general this corrective measure is not very usual.

Figure 15: Axis leveling.

To check that the two discs are in parallel, it is convenient to be able to introduce a gauge of 0.003́ ́/0.07mm on all four sides and it must be able to go through without difficulties.

Figure 16: Check axis leveling, with a gauge.

This is hard work, but it is important. A misalignment of the driveshaft will surely bring  lot of eccentricity and, therefore, noise and vibrations.

Figure 17: Checking alignment with a gauge.

A well done job pays off, proof of this are the videos we show below where you can see the Yanmar 2GM20 engine before and after the installation of the Ellebogen marine supports.

We thank very much the owner of the Oryx boat that has port in Marseille, Mr. Gérard Samblancat for the detailed photos and the installation.

Without a doubt, an Ellebogener!