[C320-list] replacing motor mounts

[Rick Sulewski]

HollyHonu #264,

I replaced the front motor mounts in 1996 when I received notice of a
Westerbeke motor mount recall the same time I was sent two upgraded front
mounts due to a high number of front mounts that were expected to fail due
to the rubber to steel design mount at that time.

I am thinking about replacing all four mounts given the  age of the rubber
when I replace the cutlass bearing, as that would also be the time to
re-align the prop shaft to the engine couple. It would then be necessary
adjust the motor mount up/down stud nuts and / or side to side adjustment
bolts on the motor mounts attached to the hull grind ( stringer) to ensure
that the shaft alignment to the  engine coupler falls within tolerances to
avoid premature cutlass bearing wear and ensure the packing gland is not
prematurely worn allowing excessive water migration into the bilge.

Since I replaced the front mounts years ago, there are now videos posted on
the internet clearly providing guidance and tips. I captured the process I
used to get the job done which is similar to what is posted on the web
videos now available on YouTube.

Motor Mount Replacement Process:
 1.  I replaced the original front motor mounts by first separating the prop
to engine coupler so I could later tilt the engine to slide out the mounts,
one corner at a time.  

2. I noted the number of stud treads exposed on either side of the up/down
adjustment nuts and marked the new motor mount stud for that engine corner
accordingly so I could duplicate the same adjustment setting on the new
mount for that specific corner. 

3. Traced the outline of the original motor mount as it rested on the hull
engine grid ( stringer) to ensure the side to side bolts adjustment template
spacing is recorded before removing the engine mount to hull grid by
removing the hull attachment bolts. 

4.  I then removed the stud adjustment nut securing the engine to the mount
so the engine could be lifted above the mount stud in the next step. Next I
removed the bolts attaching the mount to the hull grid so I may then be
prepared to slide out the mount in the next step. Have the new mount ready
to install with the nut adjustment already recorded to mirror the old mount
tread settings noted in the preparation step # 2.

5. Using a small pry bar,  lift the motor attachment above the mount stud,
just high enough to slide away the old mount and immediately replace it with
a new mount.

6. Bolt down the motor mount to the hull grid against the traced outline of
the  former mount, but  do not snug the bolts just yet if you are going to
check the coupler alignment before attaching the prop shaft side of the
coupler  to the transmission/ engine side of the coupler. Also install the
top adjustment nut, but do not snug the adjustment nuts if you are going to
check alignment before reattaching the coupler. 

7. The last step was to check for prop shaft alignment since the shaft to
engine coupler is already separated. I used a feeler gauge to check four 90
degree couple circumference measurement points. Used the up and down
adjustment nuts and the side to side mount bolts to draw the engine within
the tolerance limits for each of the 90 degree points on the coupler by
making further (small) motor mount adjustments ( up/down or side to side).
This whole process is really a mental mind puzzle that is very logical and
very simple once the relationship of the engine to the coupler variances are
understood.

Lessons learned: The simply solution is to pay someone to do all of the
work. However, I found that unless you have a yard worker who is very
proficient at this type of work because they have had some experience and
have the patience to get it right, you may find the quality of your work
superior to a first time episode with an inexperienced yard worker.  Even an
experienced yard worker who is less inclined to be accurate when rushing to
finish the task with a high degree of accuracy may not do as well as you may
do. 

I had to do-over the coupler alignment myself in 2001 after I had the first
cutlass replaced when I upgraded to a stainless shaft and also needed to
have the prop strut re-bedded because we had wrapped a line around the prop
that resulted in the engine being stalled out while under 2,500 rpm load  as
we were motoring along that resulted in damage to the bronze shaft and the
strut. After checking to see if the repair/replacement job had been
completed as expected, I found that the engine was badly out of alignment
when I separating the coupler to check if the alignment was done correctly.
The alignment had not fallen within the tolerances specified by Westerbeke.
It was a weekend after the yard help had left for the day, but it only took
me an hour to get it right since I had the earlier experience with the motor
mount replacement in 96. I have since put 600 hours on the boat over the
last decade and the cutlass remains firm but is beginning to show natural
wear. However, due to the correct shaft alignment over the years, my packing
gland wear and drip rate has also been minimal.

By chance was your failed mount a front mount?  The reason I inquire you may
have a reason to contact the engine manufacturer. If you have a Westerbeke
you may learn if your engine was on the list for motor mount replacement and
even if you have another engine manufacturer it may be worth a phone call to
check  with a technical support person who may have the authority to comp
you  some replacement motor mounts.

Hope this message proves to be helpful.

Rick
My-Ria Hull #277 

-----Original Message-----
From: c320-list-bounces at lists.catalina320.com
[mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of HOLLY DAVIS
Sent: Friday, January 20, 2012 8:08 PM
To: c320-list at catalina320.com
Subject: [C320-list] replacing motor mounts


Rick,I have a 1995 320 and just discovered that one of my motor mounts is
broken and the others are rusty, so I am looking to replace all four.Have
you changed yours and how did it go?HollyHonu #264

> From: rsulewski at bex.net
> To: C320-List at Catalina320.com
> Date: Sun, 6 Nov 2011 19:40:10 -0500
> Subject: Re: [C320-list] Flexible coupler effectiveness?
> 
> Shawn,
> 
> I have a Westerbeke 30B engine and it also transmits a fair amount of 
> vibration, depending on the selected RPM on my 95 320.
> 
>  I am thinking about changing out the motor mounts when I need to 
> replace the cutlass bearing in a few years. It also occurred to me to 
> consider changing out the rubber hose that connects the stuffing box 
> to the thru-hull prop shaft tube given the age of the boat.
> 
> Have you considered that your motor mounts may be contributing to 
> excessive vibration and engine movement that could impact the wear and 
> tear on the cutlass bearing?
> 
> I wonder if any other owners of 93-97 boats have had a need to change 
> their motor mounts or that thick rubber connecting hose between the 
> prop shaft hull tube and the stuffing box?
> 
> Rick
> My-Ria #277
> 
> 
> 
> -----Original Message-----
> From: c320-list-bounces at lists.catalina320.com
> [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Shawn 
> Maloney
> Sent: Sunday, November 06, 2011 11:01 AM
> To: C320-List at Catalina320.com
> Subject: [C320-list] Flexible coupler effectiveness?
> 
> I have a Perkins engine in my 93 C320.  Though these engines are tough 
> and reliable, they are not as smooth as the Yanmar.  I have 2100 hours 
> and plan to replace the cutlass bearing as a maintenance item.  At the 
> same time I may consider a stainless steel shaft ( as some have done 
> on this list) and I am considering adding a flexible coupler.  It 
> seems that the coupler is about 1 ¼ inches thick and I would resize the
shaft to compensate for this.
> 
> 
>  
> 
> I would like to hear any comments as to the effectiveness of the 
> coupler at reducing vibrations and adjusting for alignment issues.  
> Thanks
> 
>  
> 
> Shawn Maloney
> 
> Hull #14
> 
>