Re: [Amel] Maramu engine replacement


Thanks John.  There is lots to consider.  Right now I'm waiting to hear back on the avaiability of the 75 hp and 54 hp motors.  I heard that there are none available now and they won't have any for 3 months.  This messes with my timing since I'm hoping to head south (from Seattle) August and wanted as much time as possibl to put hours on the engine before heading out.  I do not want to wait another year!    I'm going to look at the gear box connection to this weekend and see if the bracket used on the ZF 25 could be used or modified for use on the ZF 30.  It makes so much sense to keep this connection if possible so that I only need to worry about modifying the forward mount to get proper alignment.  

Thanks again for your advise.  After I make my final decision and begin the replacement I'll keep you posted and supply pictures.


S/V Chara

Maramu hin#173

----- Original Message -----

From: "jjjk12s" <jjjk12s@...>
To: amelyachtowners@...
Sent: Tuesday, February 14, 2012 7:12:49 PM
Subject: Re: [Amel] Maramu engine replacement



Some more thoughts on your engine change based on my recent searches for an engine for my boat...

Both the 54 or 75 hp yanmars can be had standard with a ZF30M box rather than a ZF25M but this is about 36mm longer and 5mm more vertical offset than the ZF25M (Hurth HBW250). To use Eric's neat solution with the aft mounts you would need to check if that extra size was an issue otherwise you could reuse your old gear box or buy a ZF25M and fit it to a bobtail yanmar - note they offer the off-the-shelf engines with the gearbox with the slightly higher rating.

The other vertical offset gearbox ZF do in that size range is the ZF25 which is hydraulic rather then the other two which are mechanical(sorry I put a H instead of an M in my last post). This is about 52mm longer than the ZF25M.

Personally I would rather have a 75 yanmar rather than a 54 hp yanmar in my maramu even though the 54 is probably adequate. In adverse conditions and maybe a bit of fouling I would like more power. I think basically the yanmar 4jh4 75hp is the most obvious choice unless you have a specific reason otherwise. I believe the reliability of the turbo is not an issue.

Depending upon how the engine mounts fit, I would also be happy with a slower revving non turbo engine like the Beta, Westebeke 65A or Cummins 4b3.3 depending on local support. Beta offer custom engine mounts and a shallow sump option (although the shallow sump needs more frequent oil changes).

I own a 2005 Perkins M65 which is similar to these engines(67hp, 3 Litre, 4 cylider normally aspirated, max rpm 2600) and have been undecided whether to replace the M60 in my maramu with this or a new 75hp yanmar. The M65 is a great engine but modern engines with things like indect injection and turbos comply better with modern regulations. I believe the M65 was discontinued because of not being able to meet latest emissions regulations. On the other hand I don't think these modern engines are expected to last 10,000+ hours.

On a seperate note the turbo yanmar is sensitive to back pressure. It has a 3" exhaust and it is recommended to increase this after the water trap. My mechanic stepped up to 4" on a 3m hose run. On a short hose run with few bends it is not so important but the large hose can present issues such as new water trap and hull fitting.

John Maramu Popeye #91

--- In amelyachtowners@... , Bsarff <bsarff@...> wrote:

I was thinking it would be better not to have the turbo since it's one more thing to fail. I' still waiting the hear the availability of both these engines.


On Feb 14, 2012, at 8:40 AM, Eric Lindholm <etlindholm@...> wrote:

As a bit more input for you, I was going to go the 54 so I did not have to worry
about a turbo. My local Yanmar dealer who is recognized nationally for his
expertise in repowers, recomended that I put in the 73 because of the turbo. He
said it would get better performance and economy with the turbo, even at cruise
speed. Overall you will get better fuel economy with the new motor. My dealer
guestimated 18% increase before the repower, and that is about what it ended up
being. I now do about 6.5 knots in perfect conditions burning 1 gph, where I
used to burn 1.3.

Eric Maramu 105

From: "bsarff@..." <bsarff@...>
To: amelyachtowners@...
Sent: Tue, February 14, 2012 7:00:01 AM
Subject: Re: [Amel] Maramu engine replacement

Thanks for your input. I'm still nervous about reducing HP but I'll look into
it further. A gain...Thanks!

----- Original Message -----
From: "Eric Lindholm" <etlindholm@...>
To: amelyachtowners@...
Sent: Monday, February 13, 2012 7:32:12 PM
Subject: Re: [Amel] Maramu engine replacement

I was going to do the same thing, but as I indicated the ZF 25 and 30 were both
unavailable for at least 4 months, and I figured it would be 6. You might want
to check on the current availability. I decided to have my trans opened up to
have it checked, and it showed almost no wear after 15 years (the original was
replaced in 1990) and 4500 hours. It takes 28 hp to drive a Maramu 6.5 knots, so

the 54 should be fine. Have fun.

Eric Maramu 105

From: " bsarff@... " < bsarff@... >
To: amelyachtowners@...
Sent: Mon, February 13, 2012 4:20:19 PM
Subject: Re: [Amel] Maramu engine replacement

Thanks Eric. This is great information. The dealer is saying that the 54 hp
engine is also a good match for replacing the 60 hp Perkins I know have. I
don't know if this is true or not. The zf 30 is very close to the ZF 25 and
Hp rating so I'm leaning toward buying a complete engine/trans package which
will give me a 5 year warrenty on both units. The 54 hp unit if more readily
available which is why I'm considering it.

Does anyone have a thought on installing a 54 hp Yanmar in at Maramu?

Thanks to everyone who has replied/commented on my inquiry.


Maramu Hin 173

----- Original Message -----

From: "Eric Lindholm" etlindholm@...
To: amelyachtowners@...
Sent: Friday, February 10, 2012 9:26:25 PM
Subject: Re: [Amel] Maramu engine replacement

Bob, I replaced my motor with the Yanmar 4JH4, and used my original
transmission, which I think is the same as yours. I had my transmission rebuilt
as needed by a local shop. I was going to get a new trans, but ZF (who bought
out Hurth) was back ordered 6 months. It ended up that by using my old trans the

installation was a lot easier. First you can use your old rear motor mounts. The

Hurth trans bolts up to an adapter plate, that will bolt directly on the Yanmar.

The rear motor mounts are mounted to this adapter plate. The Yanmar supplied
rear mounts are bolted to the engine. The Yanmar engine mounts are on 18 inch
centers, whereas the engine beds and your old mounts are on 22 1/2 inch centers.

By using your old trans and adapter plate you eliminate a lot of alignment
issues. It may be that the ZF gearbox will mount on this adapter plate, and you
could do the same thing, but I don't know. When I installed my engine, I was
able to use new rubber engine mounts (not the Yanmar, they are to tall) and the
rear mounts lined up exactly with the original Amel mounting bolts. On the front

mounts I bolted a 1/2 steel plate on the original engine bed, using the original

Amel mounting bolts, to bring it in to the 18 inch centers required for the
Yanmar engine mount alignment. The other advantage to using the original
trans is I was able to keep my shaft mounted alternator, without having to
fabricate a new mount. If you go with a new trans, I would not go with any down

angle, as you will have to do considerable modification to the engine beds. The
front of the engine will have to be dropped about 6 inches, and you will
therefore have to remove that much of you engine beds I believe. The engine beds

have steel plates embedded in them into which the original motors mounts are
bolted. Very strong. I was able to reuse all of them. Handy. The only thing to
have to modify on the engine beds with the original trans, is the area around
the oil filter, which comes out of the right hand side, right at the level of
the top of the engine bed. You have to cut it out in a half moon shape about an

The engine swap was actually quite simple, and I can provide you with photos of
my install, if you go a similar route.

Eric, Maramu 105

From: Bob Sarff < bsarff@... >
To: amelyachtowners@...
Sent: Fri, February 10, 2012 10:14:15 AM
Subject: [Amel] Maramu engine replacement

I'm looking to replace my Perkins 4.154 engine with a Hurth HBW 250-3R trans
with a gear ratio of 2.74 soon and would like your opinion of a couple of
options. I know some of you have replaced your motors with the Yanmar 4JH4-TE.
Did you replace the transmission at the same time or rebuild your old one? If
you purchases a new one, which model did you purchase. My concern at this point
is that the dealer I'm working with shows transmissions that have a 7 degree
down angle and the one I have has an offset rather then a down angle.

Has anyone used the 75 hp Volvo instead of the Yanmar. Is there an
advandage/disadvantage either way?

Thanks for any advise you can provide.

S/V Chara
Hin 173

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