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**s/v Jedi** · 16-07-2009, 21:44

I definitely need to replace the engine mounts. They look like they will break soon...

I made photo's of the mounts, measured them, but I can't find any pictures and dimensions on the web. Is there someone here who can identify these mounts (see attachment) or point me to some web page that helps?

Also: we have an Aqua Drive system (CV joints and thrust bearing) and from the documentation I understand that I can use softer mounts than usual because the thrust force isn't transferred to the mounts anymore (just torque). Does anyone know more or have these?

thanks,
Nick.

**neilpride** · 16-07-2009, 22:03

Looks like yanmar mounts, and dont look so bad, try any yanmar dealer.
And the aquadrive need a bulkhead betwen the shaft log and the engine coupling to transfer the loads to this bulkhead , but still the engine need the elastic mounts, and the yanmars are very light engines , more light alloys , aluminium, vibrate some in low revs, yanmars like hig revs,any way looks like yanmar mounts, and i see the screws directly to the engine bed?? you know whats goin on in a 360 roll??
Happy searching.

**s/v Jedi** · 16-07-2009, 22:35

Neil,

Yes, my guess was that they are Yanmar mounts, but only because it is a Yanmar engine and the mounts don't look like the AquaDrive mounts. You think they don't look bad? I think they are 15 yrs old....

Thrust bearing: oh yes, it's attached to very substantial bulkheads and stringers. But the thing is that these Yanmar mounts are clearly designed to cope with propeller thrust forces while I don't have those. Theinfo I found about AquaDrive says that their mounts are designed to cope with the torque forces only and much softer so that less vibration is transferred. I'm looking for someone with more info or experience with those.

About the roll: yes, you probably mean that I should put steel wires around the mounts to hold the engine when the rubber fails? I plan to do that. The engine stayed put while at anchor in hurricane Ivan, while the spreaders touched the water on both sides! Another reason to replace the mounts....

ciao!
Nick.

**neilpride** · 16-07-2009, 22:47

Jedi with all the respect, engine mounts are designed to absorv engine vibrations to the hull and prop forces, the aquadrive deal with the prop forces but dont with engine normal runing vibrations, if you mount the engine directly to the engine beds with out elastic mounts vibrations goo straight to the hull, insane idea.
15 years old mount need replace.
Steel wires around the mounts??? not sure.
I have my perkins 4236 mounted in a L section steel plate atached to the stringers and the mounts screwed to the plate with bolts and washers -
Good luck.

svquest2 · 16-07-2009, 23:13

Does this help any?

Fisheries Supply Search: Engine mounts

Joe S

captain58sailin · 16-07-2009, 23:16

s/v Jedi,
I wouldn't be in a big hurry to change out the mounts, only if the rubber has gotten hard. I had some vibration in my hull at a certain rpm, so thinking the mounts had given up the ghost, I pulled the engine and pulled the mounts and once I cleaned them up from the oil & such, I found that the mounts had gotten out of adjustment and allowed the engine to sit down on the hull, hence the vibration. Once I had cleaned the mounts I found that the rubber was still in very good condition and I didn't have to replace them. I was in contact with an outfit out of Australia that had some very good mounts available. I don't know if they would have the exact same configuration that you have now, I think that you could find some that would fill the bill. I am getting ready to fly home and should be there in a couple of days, and I can look them up and see if I still have their info. PM me if you want me to see if I can dig up my old information.

NCboatrx · 17-07-2009, 05:09

Yanmar recommend that this type of flex mount be changed periodically. This one seems to have too little clearance between the top metal and the raised center piece of the base. I suggest that you contact a Yanmar dealer. These mounts are numbered by Yanmar and you must get the correct ones for your particular engine to ensure smoothness.
Stanley

**Tellie** · 17-07-2009, 06:44

Yanmar will probably tell you to change the mounts every year. Not something most people do. But fifteen years is a long time. In the picture it looks as if the mount has collapsed and is due for a change. The eveidence is in the clearance between the two steel plates in the middle where the V shaped part comes close to the flat part. Also, avoid diesel fuel from getting on Yanmar motor mounts like the plague.

**s/v Jedi** · 17-07-2009, 08:22

Quote:

Originally Posted by neilpride

Jedi with all the respect, engine mounts are designed to absorv engine vibrations to the hull and prop forces, the aquadrive deal with the prop forces but dont with engine normal runing vibrations, if you mount the engine directly to the engine beds with out elastic mounts vibrations goo straight to the hull, insane idea.

When AquaDrive manufactures extra soft engine mounts to be used with their CV joints & thrust bearing, why do you insist that is equal to mounting directly to the engine bed without elastic mounts???!!! Their mounts are more elastic and flexible than the normal ones!
See this for more info on the AquaDrive system, the mounts are part of it: Aquadrive - Engine Mounts

Also, I know steel boats that have the engine bolted on without flexible mounts... they tell me this is normal and all the commercial boats have it that way, but for steel & heavy only.

Quote:

Steel wires around the mounts??? not sure.

See this post and the thread it is in: http://www.cruisersforum.com/forums/...3&postcount=27

Quote:

I have my perkins 4236 mounted in a L section steel plate atached to the stringers and the mounts screwed to the plate with bolts and washers

Okay, but what do you think is wrong with my setup? I think our bed is about 1" solid glass and I doubt it will be weaker than you steel plate??

cheers,
Nick.

imagine2frolic · 17-07-2009, 08:32

I think NC is close to the mark. The top, and bottom mouns look very close, and this is without any torque. If they are touching there will be a shiny spot that will be visible with a mirror at worst. I deal with mounts daily, and that looks VERY close......i2f

imagine2frolic · 17-07-2009, 08:34

& they do look exactly like my Yanmar mounts.....i2f

**neilpride** · 17-07-2009, 11:41

Yes you totally right jedi, i dont cacht your idea yesterday, if the aquadrive mounts are soft, good , im sorry i miss understand your post.
Your setup for the engine beds maybe dont look so bad , i dont know how heavy is your yanmar, but my perkins is 470 kg with the transmision, in the last engine overhaul y made the steel plate job in the beds, big project, my engine beds are also close to a 1 inch fiberglass covered wood, and i dont like the idea in a 360 roll to have 470 kg off iron with just the screws directly to the beds, any way.
Hey Happy sailing.

**s/v Jedi** · 17-07-2009, 16:40

Okay, some info:

The engine is a Yanmar 4LH-HTE. That's 140 hp, turbo-charger with intercooler. It weighs 350 kg (772 lb) dry. Another 20 kg for oil and coolant. I also have two huge extra alternators, let say total weight 30 kg and a crash-pump of 10 kg so total weight is 410 kg.

Yanmar talks about an "Indication No." for the flexible mounts and all four should be "300". I guess that means 300 lb.? That number should be on the rubber part they say in the manual.... well I will try to find it but I fear it might not be readable anymore.

The base of the mounts is 8-1/2" x 2-3/8", the spacing of the bolts is 7-1/4" (185 mm) and the distance between engine bed and L-bracket is 4-1/8". The stud is 18mm diameter.

Pfff... I guess I'll try to email AquaDrive and Yanmar and choose the one that responds. I don't feel like going to the dealer here because... well, we're in Panama.

I also guess that the Yanmar mounts can't be found on-line anywhere. I would like to find a drawing to check the measurements and convert that to an article number that I can order from Miami.

So, there must be more members with this engine who replaced the mounts!! Pls. followup with what you know! ;-)

thanks,
Nick.