[C320-list] New Engine Mounts

[Kirk McCullough]

THe engine rattles around on the mounts, make a nasty noise etc, does this 
even if the shaft isn't turning , so it seems its not the shaft hitting the 
hull, just the shaking of the motor,alt like its going to stall or 
something.
----- Original Message ----- 
From: "Martin Raphael" <mraphael at q.com>
To: <C320-List at Catalina320.com>
Sent: Thursday, June 26, 2008 7:25 AM
Subject: Re: [C320-list] New Engine Mounts


> Balance of the prop (flex-o-fold) and condition of the shaft (stainless 
> steel) could be contributors and I plan to check those out next.  I don't 
> think they are the issue, as I had no problems at higher RPMs and I would 
> think shaft and prop problems would be worse at greater speeds.  When you 
> say "shakes" I wonder what that mean?  In my case, with the new mounts the 
> movement is extreme and the shaft actually knocks against the tube .
> ----- Original Message ----- 
> From: "Pat Moriarty" <patm at psiurethanes.com>
> To: <C320-List at Catalina320.com>
> Sent: Thursday, June 26, 2008 5:24 AM
> Subject: Re: [C320-list] New Engine Mounts
>
>
>> Only one thought, are you sure about the shaft and prop being true and 
>> balanced?
>> Mine only shakes at dead idle when starting from sitting still or 
>> changing directions but at 1000 RPM no shake, 1994 Perkins 600 hrs 
>> original mounts.
>>
>> Pat #130At 07:55 PM 6/25/2008, you wrote:
>>>I just replaced my non-stock engine mounts with the stock Perkins mounts 
>>>per the thread below.  To my great distress, the engine now vibrates 
>>>wildly, to the point that the shaft bounces against the shaft tunnel when 
>>>in gear.  I had hoped that the softer stock mounts would solve a 
>>>long-lasting vibration and noise issue I have been experiencing.  Now my 
>>>mechanic says the real culprit may be in the valves and they will be 
>>>checking that out tomorrow. He says he has encountered 2 other Perkins 
>>>that have serious valve rocker wear, and that this can cause the 
>>>vibration.  Have any of you heard of this problem or experienced it 
>>>yourselves?  Right now I'm feeling rather foolish for having invested a 
>>>huge amount of money in new mounts when those may not have been the 
>>>culprit.  BTW, mine is a 94 Perkins M30.  So let this be a caution before 
>>>blindly switching out motor mounts.  I may have to just go back to the 
>>>old mounts and live with the annoying but tolerable vibration.
>>>Martin Raphael
>>>Rhapsody #108
>>>----- Original Message ----- From: "Martin Raphael" <mraphael at q.com>
>>>To: <C320-List at Catalina320.com>
>>>Sent: Sunday, June 01, 2008 7:16 PM
>>>Subject: Re: [C320-list] New Engine Mounts
>>>
>>>
>>>>Just a thought here...the engine will vibrate the same way in relation 
>>>>to RPM whether you have old or new engine mounts, wouldn't it?  Engine 
>>>>mounts will affect how that vibration is transmitted to the hull, and 
>>>>thus what we hear or feel.  Stiffer mounts will transmit more directly 
>>>>to the hull...softer mounts will absorb vibration.  So I wonder if 
>>>>Mike's new mounts were actually "softer" than the worn mounts he 
>>>>replaced.  I say this because some years ago (2003) I had new engine 
>>>>mounts installed, and the engine noise and vibration, especially at low 
>>>>RPMs, went up tremendously.  I have always thought this was because the 
>>>>new engine mounts were much stiffer than the originals.  Other thoughts?
>>>>Martin Raphael
>>>>Rhapsody #108
>>>>----- Original Message ----- From: "Kirk McCullough" 
>>>><kirk.mccullough at telus.net>
>>>>To: <C320-List at Catalina320.com>
>>>>Sent: Wednesday, May 28, 2008 9:18 AM
>>>>Subject: Re: [C320-list] New Engine Mounts
>>>>
>>>>
>>>>>Mike
>>>>>
>>>>>Good advice, I'll add new mounts to the list. I have always put up with 
>>>>>the "Perkins shudder" at low RPM, made even a little worse with the 
>>>>>high pitched Kiwi prop when in reverse.
>>>>>
>>>>>Kirk
>>>>>#124
>>>>>----- Original Message ----- From: "Mike Shoffner" 
>>>>><drshoffner at yahoo.com>
>>>>>To: <c320-list at lists.catalina320.com>
>>>>>Sent: Sunday, May 25, 2008 6:08 PM
>>>>>Subject: [C320-list] New Engine Mounts
>>>>>
>>>>>
>>>>>Over the years there have been threads devoted to the vibrations at low 
>>>>>RPM's of the older boats with Perkins engines. I've noted this with my 
>>>>>boat ever since I boughtit 4 years ago, and I've just attributed it to 
>>>>>being a characteristic of the Perkins engine. Recently, because of my 
>>>>>cutless bearing wearing out in one season of use, I had my shaft 
>>>>>allignment checked and was advised I needed new engine mounts. What a 
>>>>>difference!! The old "Perkins vibrations" apparently were due to worn 
>>>>>engine mounts' and with new mounts there are zero vibrations at low 
>>>>>RPM's. At higher RPM's engine noise and vibrations are also noticably 
>>>>>reduced as well. Mine is a '94 model and probably needed new mounts for 
>>>>>several years. I would advise owhners of more mature boats to consider 
>>>>>having their engine mounts replaced if they're having problems similar 
>>>>>to mine.
>>>>>Regards,
>>>>>Mike
>>>>>#171
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>--
>>>>>No virus found in this incoming message.
>>>>>Checked by AVG.
>>>>>Version: 7.5.524 / Virus Database: 269.24.1/1469 - Release Date: 
>>>>>5/27/2008 1:25 PM
>>>>>
>>>>>
>>>
>>
>> Pat Moriarty
>> PSI Urethanes Inc
>> PH: 800-888-5156  Fax: 512-837-8733
>> Please visit our web site at
>> www.psiurethanes.com
>>
>>
>>
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