[C320-list] New shaft

[Gene Helfman]

Our mechanic on #398 (1997) says the Yamaha 3GM30F is called a "shaker" at
low rpm, i.e., it's in the design.  He's worked on every type of diesel
from a few hp to several thousand and knows his stuff.  Take home: live
with it I guess.


On Tue, Jun 17, 2014 at 2:34 PM, christopher Brearley <cjbrearley at gmail.com>
wrote:

> Hi Jerry,
>
> I have recently replaced my engine mounts with genuine Yanmah product and
> there
> is still the vibration when reducing RPM. Cutless bearing is also fine, so
> I am unsure
> of what is causing it. Reduce RPM slowly?
>
> Chris,
>
> WeaRitz@
> #374
>
>
> On 17/06/2014, at 10:19 PM, jsheets at aol.com wrote:
>
> > Thanks all for the responses/advice. I suspect I will be adding motor
> mounts to my project list.
> >
> > Jerry
> > JellyRoll  #890
> >
> >> On Jun 16, 2014, at 5:35 PM, Jim Brown <jbrown5093 at gmail.com> wrote:
> >>
> >> You can check if the vibration is in the motor mounts pretty easily.
> >> Uncover the engine and (watch out for the belts and pulleys) put a
> longish
> >> pry bar or big screw driver in the motor mount. Pull up hard. You'll be
> >> surprised about how much they raise up. With the motor mount stressed
> >> throttle up and if it is a mount the vibration should be gone or much
> >> better. Do each mount individually. Mine (2004) are very weak and when
> >> throttling down to idle it sounds like a bucket of bolts just above idle
> >> speed when there is significant vibration. With the mounts stressed-no
> >> noise at all. Getting ready to replace them . I believe that yanmar
> >> recommends replacement every 4-5 years (I suspect nobody does that).
> >>
> >> Jim Brown
> >>
> >>
> >>> On Mon, Jun 16, 2014 at 4:35 PM, <jsheets at aol.com> wrote:
> >>>
> >>> Probably around 800 - 1000.
> >>>
> >>> Jerry
> >>>
> >>>> On Jun 16, 2014, at 3:11 PM, <tharrison at innovations-plus.com> wrote:
> >>>>
> >>>> Just wondering what is you starting RPM"s
> >>>>
> >>>> Ted - hull 424
> >>>>
> >>>> -----Original Message-----
> >>>> From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On
> >>> Behalf
> >>>> Of Andrew Santangelo
> >>>> Sent: June-16-14 2:30 PM
> >>>> To: C320-List at Catalina320.com
> >>>> Subject: Re: [C320-list] New shaft
> >>>>
> >>>> Jerry,
> >>>>
> >>>> It could be related tot he cutlass bearing.  I have had this replaced
> 3
> >>>> times over the last 18 years on Dawn Treader.  I also had a drive
> saver
> >>>> installed for the Autoprop and it saves on wear and tear with the
> engine.
> >>>>
> >>>> Andrew Santangelo
> >>>>
> >>>> C320 "Dawn Treader"
> >>>> #333
> >>>> Holland, MI
> >>>>
> >>>> J22 "Blitzkrieg"
> >>>> Elephant Butte, New Mexico
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>> On Jun 16, 2014, at 2:26 PM, jsheets at aol.com wrote:
> >>>>>
> >>>>> I recently had a new prop shaft installed due to some previous
> problems
> >>>> with the old shaft. Since installed, on two occasions I have had a
> strong
> >>>> vibration of the shaft and transmission when starting out at low
> speeds.
> >>>> Once given more throttle it works itself out. Does not do it when
> slowing
> >>>> down from higher speed, only in early acceleration. Mechanic is
> convinced
> >>>> the alignment is correct. Says he thinks part of the problem is the
> motor
> >>>> mounts Yanmar uses, allowing for too much movement of the motor. Any
> >>>> thoughts or similar experience anyone can share is appreciated.
> >>>>>
> >>>>> Jerry
> >>>>>
> >>>>> JellyRoll  #890
> >>>
>
>


-- 
Gene Helfman, Professor Emeritus
Odum School of Ecology, University of Georgia
PERMANENT address:
    498 Shoreland Dr., Lopez Is., WA 98261
    (360) 468-2136
    genehelfman at gmail.com

"You noticed nobody gives a damn about beached minnows."