Yanmar Engine mounts.

[smokey73]

Interesting. I am now OFFICIALLY CONFUSED. Lets talk FORE and AFT, PORT and Starboard, not front and back and left and right when we are talking about boats. That way there is no confusion as to what direction we are facing and from what orientation we are viewing the boat. The following discussion ASSUMES WE ARE NOT TALKING ABOUT SAILDRIVE INSTALLATIONS.

The Ellebogen site shows that some Yanmar 2Gm and 3GM series mount specs are 100# fore and #75 aft (they say front of engine and back, but you can see that the transmission "hangs" off the back so that is aft for other than a saildrive.) I didn't see any where the 100 are aft and the 75 forward. On the Yanmar 4JH2 series the mount specs are 200# Port and 150# Stbd. If you look at the specs for a Yanmar OEM 200# mount (link 3) you'll see they say the same thing.. For the 2GM and 3GM the Yanmar part description says the 100# goes on the front of the engine. I think the front of the engine is fore, not aft on a shaft drive. I have never seen or heard of the transmission end called the front of any engine.

Ellebogen engine mount kit 75-100

Marine Engine mount kit. Stress and corrosion tested for warranty and safety. ➤ Online sales from factory

ellebogen.com

Engine mount kit - Ellebogen

Marine Engine mount kit. Stress and corrosion tested for warranty and safety. ➤ Online sales from factory

ellebogen.com

YANMAR 129470-08350 Mount, Flexible 200

Buy YANMAR Front or Rear Engine mount - 4JH - 200 - 129470-08350; Description Duplicate YANMAR Engine mount '200' Yanmar part number: 129470-08350 Genuine Yanmar Parts & Accessories This listing is for one Engine mount for: 4JH Please note that these arenumber '200' This refers to the hardness...

palmerpower.com

YANMAR 124772-08341 Mount, Flexible 100

Buy YANMAR FRONT Engine mount - 2GM - 2GM20F - 3GM - 3GM30F - 2QM15 - 3JH -100 -124772-08341; Description YANMAR Engine mount '100' Yanmar part number: 124772-08341 Genuine Yanmar Parts & Accessories This listing is for one Front Engine mount for: 2GM 2GMF 2GM20 2GM20F 3GM 3GMF 3GM30 3GM30F...

palmerpower.com

 

[Tally Ho]

I was out at my boat this week and checked my engine mounts (Yanmar 2GM20F).

It looked like the fore ones are 75# and the aft ones are 100# (but it was hard for me to see the stamp on the aft ones).

If the engine is pretty balanced fore and aft, the I guess it makes sense to have 100# mounts aft to help handle the weight of the transmission.

I do have a few Yanmar manuals around here somewhere…I will see if they make any notes.


Greg

 

[Jan_H]

It is indeed a bit confusing. The Ellebogen site includes nice little pics to show where the various sized mounts should be placed, e.g. for the 2GM/3GM series:

It does seem a bit counterintuitive, but perhaps that's indeed how the weight is distributed.
For the 3JH series, the mounts are:

I read somewhere that's to accommodate the higher compressive load in the direction of rotation, but isn't that similar for all engines?
I'm sure there's a rational explanation though.
Jan

 

[Ralph Johnstone]

Yup, no doubt about it. Ellebogen's drawing is the clearest documentation I've seen on the subject. Excellent proof of your source on your part @smokey73 .

Yanmar is worse than terrible when it comes to clarity on the position of their parts as shown in this extract from their parts manual:

​

And there you have it, like it or lump it, take it or leave it. I have looked through all of the Yanmar manuals which I have and nowhere was I able to locate any reference to which mount goes to either the forward or aft part of the engine. Also, my apologies @smokey73 for my use of front and rear when referring to the engine, but I only refer to "fore" and "aft" when referring to the entire boat as a whole. The internal components I refer to by front and back such as when referring to an instrument, a device, or maybe the microwave oven.

One item I can offer as to which mount goes where is a time in 2010 when I had to replace my aft starboard mount due to damage. It was soaked in diesel from a very slow fuel leak and I wasn't going to take any chances down the road of its failing so OUT she goes. This is the damaged engine mount after removal :

On the LH rubber block, you can just make out the 100 in a circle if you zoom in on it. Remember, this mount is near the Xmission on the aft end of the engine and was installed in the Hunter factory in 1998. I bought the boat new in 1998 and it was shipped from the Hunter plant in Fla. to BC Canada.

The replacement for this damaged mount was purchased from my Yanmar dealer here in Vancouver as shown in their invoice :

​

The engine part no. which was sold to me was Y124772-08341, the same number as given in the Yanmar parts manual for the #100 engine mount as previously shown above and repeated below :

I would also add that the "parts guy" at the Yanmar dealership could probably build an engine out of paper clips as a monument to his knowledge of Yanamr engines. I knew he was correct in his choice of #100 for the engine mount. After installation, I was back to #100 engine mounts on both starboard and port side of the aft end, rear end, transmission end, or whatever you want to call it.

So what we have here is Ellebogen vs. Yanmar when it comes to "where do the #100 engine mounts belong, front or back ?"

Looking at Ellebogen's claim that the #100's should be placed forward on the engine :

1. They provide a picture of where to install the four engine mounts, two #100 at the forward end and two #75 at aft end of the engine.

Looking at Yanmar's "history" which indicates the #100's should be placed aft on the engine :

1. Hunter Marine installed (2) #100 mounts on the aft portion of the engine and (2) #75 mounts on the forward portion of the engine. I feel this choice was made at the instruction of Yanmar.

2. My Yanmar dealer had no hesitation in supplying a #100 mount to replace the rear engine mount for my engine.

I was unable to find anything in their manuals about the position of the mounts.

As we are ONLY interested in the facts of this matter, and not wild supposition as most things around here are determined eg. he said, she said; my brother-in-law's father's bartender told him that blah, blah, blah; I am sending this question off to Ellebogen to get their thoughts and why they want the #100's mounted on the "front side" (their terminology).

I will post their answer.

 

[dlochner]

Yup, no doubt about it. Ellebogen's drawing is the clearest documentation I've seen on the subject. Excellent proof of your source on your part @smokey73 .

Yanmar is worse than terrible when it comes to clarity on the position of their parts as shown in this extract from their parts manual:

View attachment 228948

View attachment 228949
​

And there you have it, like it or lump it, take it or leave it. I have looked through all of the Yanmar manuals which I have and nowhere was I able to locate any reference to which mount goes to either the forward or aft part of the engine. Also, my apologies @smokey73 for my use of front and rear when referring to the engine, but I only refer to "fore" and "aft" when referring to the entire boat as a whole. The internal components I refer to by front and back such as when referring to an instrument, a device, or maybe the microwave oven.

One item I can offer as to which mount goes where is a time in 2010 when I had to replace my aft starboard mount due to damage. It was soaked in diesel from a very slow fuel leak and I wasn't going to take any chances down the road of its failing so OUT she goes. This is the damaged engine mount after removal :

View attachment 228953​

On the LH rubber block, you can just make out the 100 in a circle if you zoom in on it. Remember, this mount is near the Xmission on the aft end of the engine and was installed in the Hunter factory in 1998. I bought the boat new in 1998 and it was shipped from the Hunter plant in Fla. to BC Canada.

The replacement for this damaged mount was purchased from my Yanmar dealer here in Vancouver as shown in their invoice :

View attachment 228955
​

The engine part no. which was sold to me was Y124772-08341, the same number as given in the Yanmar parts manual for the #100 engine mount as previously shown above and repeated below :

View attachment 228957

I would also add that the "parts guy" at the Yanmar dealership could probably build an engine out of paper clips as a monument to his knowledge of Yanamr engines. I knew he was correct in his choice of #100 for the engine mount. After installation, I was back to #100 engine mounts on both starboard and port side of the aft end, rear end, transmission end, or whatever you want to call it.

So what we have here is Ellebogen vs. Yanmar when it comes to "where do the #100 engine mounts belong, front or back ?"

Looking at Ellebogen's claim that the #100's should be placed forward on the engine :

1. They provide a picture of where to install the four engine mounts, two #100 at the forward end and two #75 at aft end of the engine.

View attachment 228960​

Looking at Yanmar's "history" which indicates the #100's should be placed aft on the engine :

1. Hunter Marine installed (2) #100 mounts on the aft portion of the engine and (2) #75 mounts on the forward portion of the engine. I feel this choice was made at the instruction of Yanmar.

2. My Yanmar dealer had no hesitation in supplying a #100 mount to replace the rear engine mount for my engine.

I was unable to find anything in their manuals about the position of the mounts.

As we are ONLY interested in the facts of this matter, and not wild supposition as most things around here are determined eg. he said, she said; my brother-in-law's father's bartender told him that blah, blah, blah; I am sending this question off to Ellebogen to get their thoughts and why they want the #100's mounted on the "front side" (their terminology).

I will post their answer.

Intrigued, I took a look at the Parts List for a Yanmar 3JH2e, the engine aboard Second Star. The list calls for 3 different pairs of mounts, but only shows 4 brackets. On the other hand, Ellobogen shows 2 pairs of mounts, 100 and 150, with the 150s on the port side and 100s on the starboard side.

 

[Ralph Johnstone]

On the other hand, Ellobogen shows 2 pairs of mounts, 100 and 150, with the 150s on the port side and 100s on the starboard side.

Glancing through Ellobgen's pages on larger engine mounts, I can see that the idea of having the heavier pair of mounts on one side of the engine is to offset the torque as one would expect.

I wonder how Yanmar manages to convey that information when it appears that most of their information on engine mount positioning is passed along through folklore.

 

[kloudie1]

My original parts manual from 1984 shows 100 in front and 75 in the rear.. When I changed out the original mounts, that is the configuration I found..

 

[dlochner]

Glancing through Ellobgen's pages on larger engine mounts, I can see that the idea of having the heavier pair of mounts on one side of the engine is to offset the torque as one would expect.

I wonder how Yanmar manages to convey that information when it appears that most of their information on engine mount positioning is passed along through folklore.

There is also the weight hypothesis. The port side of the 3JH2e has the alternator, starter, heat exchanger, sea water pump and exhaust manifold. The starboard side has a bunch of fuel lines, a high pressure pump, an oil filter, a fuel filter and that's about it. I dare say the port side is a bit heavier than the starboard side.

 

[smokey73]

So you see my comment that "I am now officially confused". Hopefully @Ralph Johnstone will get a response and can clarify things. I think I'm out of the woods as far as installation since I have a 4JH2E and both the Ellebogen and Yanmar say the heavier 200# go on the Port side so there is no debate there. It is the folks with the "fore and aft" or "front and back if you will" that seem to be in a state of contradiction.

 

[Ralph Johnstone]

This will be anticlimactic to say the least. No conspiracies to be found here.

Trying to put this into some sort of order here, after my last post I had intended to write Ellobgen to find out where they got their information re the positioning of the Yanmar engine mounts. In snaking my way towards their contact page, I tripped over their community page and wondered if anyone had ever posted this same problem to Ellobgen before. The following answer from Ellobogen made perfect sense to me :

I see that the 1, 2, and 3GM models always have the heavier mounts on the front of the engine. Great, but where are the Yanmar specs to be found ?

Years ago, in addition to my Yanmar Service Manual, I would download any other literature I saw regarding GM model engine operation, maintenance, parts, and any special bulletins.

I had four Service Manuals, some with published dates and others without. Engine mounts are never mentioned in any of them. None of the manuals are posted here as they are all oversized in the 12-15 MB range. All of my Parts Manuals (2010, 2017, and 2018) showed the engine mounts with part numbers but never any information as to whether they were front or back.

Getting desperate, I started thumbing through their Operation Manuals and found a couple of them, not all of them, which addressed engine mounts :

Exactly what I expect to see in an operations manual, a few quick notes on how to install the engine.

At least this manual contains information on the engine mounts. I also see @kloudie1 was able to find information on GM engine mounts in his 1984 parts manual.

I did manage to speak to a mechanic from the Yanmar dealership here and he commented that they always replaced the engine supports in exactly the same order in which they were found.

Seems that both Hunter and O'day couldn't find the Yanmar specs so just applied logic which said to place the heavier mounts under the brackets which appeared to be under the heaviest load.

Live and learn, sort of, I guess .

 

[Tally Ho]

This will be anticlimactic to say the least. No conspiracies to be found here.

Trying to put this into some sort of order here, after my last post I had intended to write Ellobgen to find out where they got their information re the positioning of the Yanmar engine mounts. In snaking my way towards their contact page, I tripped over their community page and wondered if anyone had ever posted this same problem to Ellobgen before. The following answer from Ellobogen made perfect sense to me :

View attachment 229026
View attachment 229033

I see that the 1, 2, and 3GM models always have the heavier mounts on the front of the engine. Great, but where are the Yanmar specs to be found ?

Years ago, in addition to my Yanmar Service Manual, I would download any other literature I saw regarding GM model engine operation, maintenance, parts, and any special bulletins.

I had four Service Manuals, some with published dates and others without. Engine mounts are never mentioned in any of them. None of the manuals are posted here as they are all oversized in the 12-15 MB range. All of my Parts Manuals (2010, 2017, and 2018) showed the engine mounts with part numbers but never any information as to whether they were front or back.

View attachment 229037

Getting desperate, I started thumbing through their Operation Manuals and found a couple of them, not all of them, which addressed engine mounts :

View attachment 229029




Exactly what I expect to see in an operations manual, a few quick notes on how to install the engine.

View attachment 229035

What does the “V” mean in the chart? They show the 2GM20(F) with 100/75 mounts, or 100/100 mounts with the V note. But I don’t see what the V means.

So if I were to summarize your convo with Yanmar, just replace in kind?

Greg

 

[dlochner]

After reading the JH2 service manual and looking at the parts list the only guidance I found on motor mount placement was in a dimensioned drawing. In small print inside engine's foot print. See image. The 150 mounts go on the port side, the 100 mounts go on the starboard side.

So if I were to summarize your convo with Yanmar, just replace in kind?

At least on the 3JH2E the problem with just replacing in kind is determining what the kind is. The poor guidance from the manuals does not allow for purchasing the correct mounts add of time. At least on my installation, trying identify the mounts in place is neigh unto impossible (yes the lower nut is too low I just noticed that.).

.