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rcgamble July 10th 07 10:30 PM

3gm30fc
 
Hello,

I have a Yanmar 3gm30fc w / SD20 Saildrives that stalls when reducing RPM. I
think I've isolated the problem to be with the engine mounts. The engine
wabbles quite a bit when de-throttling and stalls. Starts right up with no
problem, idles and engages in forward and reverse with no problem. It stalls
when coming down from 2k rpm. The mounts are from 1998 so they are probably
needing to be replaced. So my question is how do I install the new mounts?
I'm told that I can 'jack' up the engine from the hatch using a 2 ton lift
and supporting rope, block the engine, remove the engine mount side bolts and
slide out the old and slide in the new. Seems straightforward though curious
if anyone has similiar experiences.

Thanks,
Bob


Capt. JG July 10th 07 11:07 PM

3gm30fc
 
"rcgamble" u35744@uwe wrote in message news:74fb3b1080ece@uwe...
Hello,

I have a Yanmar 3gm30fc w / SD20 Saildrives that stalls when reducing RPM.
I
think I've isolated the problem to be with the engine mounts. The engine
wabbles quite a bit when de-throttling and stalls. Starts right up with
no
problem, idles and engages in forward and reverse with no problem. It
stalls
when coming down from 2k rpm. The mounts are from 1998 so they are
probably
needing to be replaced. So my question is how do I install the new
mounts?
I'm told that I can 'jack' up the engine from the hatch using a 2 ton lift
and supporting rope, block the engine, remove the engine mount side bolts
and
slide out the old and slide in the new. Seems straightforward though
curious
if anyone has similiar experiences.

Thanks,
Bob



Seems straightforward enough... big issue is being able to block the engine
and get at the mounts. Are there obvious cracks? What happens if you try to
lift the engine with the blocks still fast... does the engine lift anyway?
I've only heard about people doing it...never seen it or done it. I had an
auto engine try and "climb" out of the compartment once... that was a good
indication of a couple of broken mounts.

--
"j" ganz @@
www.sailnow.com




Jeff July 11th 07 01:29 AM

3gm30fc
 
* rcgamble wrote, On 7/10/2007 5:30 PM:
Hello,

I have pair of 2GM20FC's with SD20's on my catamaran. I don't see
the connection between stalling and engine mounts. If the engine has
an imbalance, such as one cylinder not firing, or a misbehaving
folding prop, there will be a lot of wobble that can be very dramatic
on the soft saildrive mounts. The wobble sounds more like an effect,
not a cause.


I have a Yanmar 3gm30fc w / SD20 Saildrives that stalls when reducing RPM. I
think I've isolated the problem to be with the engine mounts. The engine
wabbles quite a bit when de-throttling and stalls. Starts right up with no
problem, idles and engages in forward and reverse with no problem. It stalls
when coming down from 2k rpm. The mounts are from 1998 so they are probably
needing to be replaced. So my question is how do I install the new mounts?
I'm told that I can 'jack' up the engine from the hatch using a 2 ton lift
and supporting rope, block the engine, remove the engine mount side bolts and
slide out the old and slide in the new. Seems straightforward though curious
if anyone has similiar experiences.

Thanks,
Bob


rcgamble via BoatKB.com July 11th 07 02:52 PM

3gm30fc
 
Hi Jeff,
The wobble occurs when I do a fast dethrottle from high rpm to idle. At this
point the engine wobbles side to side and then stalls. I suspect the wobble
occurs from normal centrifigal force and because I have a 'spongy' engine
mount it becomes exagerated. I believe all cylinders are firing correctly.


I can't rule out other issues that may be causing this. The wobble is the
most likely cause given what I've seen.

Thanks Much, I'll report back further findings.

-Bob



Jeff wrote:
* rcgamble wrote, On 7/10/2007 5:30 PM:
Hello,

I have pair of 2GM20FC's with SD20's on my catamaran. I don't see
the connection between stalling and engine mounts. If the engine has
an imbalance, such as one cylinder not firing, or a misbehaving
folding prop, there will be a lot of wobble that can be very dramatic
on the soft saildrive mounts. The wobble sounds more like an effect,
not a cause.

I have a Yanmar 3gm30fc w / SD20 Saildrives that stalls when reducing RPM. I
think I've isolated the problem to be with the engine mounts. The engine

[quoted text clipped - 9 lines]
Thanks,
Bob


--
www.rcgamble.com

Message posted via http://www.boatkb.com


Horvath July 21st 07 02:18 PM

3gm30fc
 
On Tue, 10 Jul 2007 21:30:05 GMT, "rcgamble" u35744@uwe wrote this
crap:

Hello,

I have a Yanmar 3gm30fc w / SD20 Saildrives that stalls when reducing RPM. I
think I've isolated the problem to be with the engine mounts. The engine
wabbles quite a bit when de-throttling and stalls. Starts right up with no
problem, idles and engages in forward and reverse with no problem. It stalls
when coming down from 2k rpm. The mounts are from 1998 so they are probably
needing to be replaced. So my question is how do I install the new mounts?
I'm told that I can 'jack' up the engine from the hatch using a 2 ton lift
and supporting rope, block the engine, remove the engine mount side bolts and
slide out the old and slide in the new. Seems straightforward though curious
if anyone has similiar experiences.



I doubt if it's the motor mounts. I'd have a mechanic look at it.
Also, I try to keep my Yanmar under 1800. I don't think it's good to
run it over that.





I'm Horvath and I approve of this post.


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