[C320-list] New Boat knocking noise

[bruceheyman at cox.net]

Jerry,
A mechanic in St. Petersburg FL told me that the mounts for the Yanmar are too soft.  He said you can get everything lined up but when the engine was up to speed the torque would cause the engine to twist and hence the log and cuttlas were no longer in alignment.  He said that for that reason Yanmar now has two versions of the mounts for our boat, one soft (quite and smooth) and the other stiff (stays in alignment).  I never verified the mechanic's information.
Good luck.
Bruce
Somerset 671 SoCal
Sent via BlackBerry by AT&T

-----Original Message-----
From: "Jerry Brown" <jbrown03 at sympatico.ca>

Date: Sun, 22 Jun 2008 07:31:12 
To:<C320-List at Catalina320.com>
Subject: Re: [C320-list] New Boat knocking noise


Hi Rick

I spent time yesterday with the dealer on the boat motoring around while he 
crawled all over it.  I think you have correctly diagnosed the problem as 
the shaft hitting the hull.  In my case it appears that the engine is 
sitting too high in the boat relative to the tunnel for the shaft to clear 
the tunnel in all conditions  When the engine is aligned and running slowly, 
the shaft just clears the tunnel.  At higher speeds and under load, the 
movement in the mounts (which are secure) is sufficient to allow the shaft 
to hit the tunnel, just as you describe.  The dealer could push briefly on 
the engine while it was running under load and immediately there was no 
knocking.  Release the engine and back came the knocking.  The next move is 
to install slightly thinner plates under the engine, lowering the who thing 
while maintaining the right overall relationships (which will change the 
angle of the shaft through the cutlass bearing somewhat) and try again. 
While this likely explains the knocking noise, it does not explain the 
engine shifting when first used.  Yesterday I noticed metal swarf around the 
engine mounts.  It turns out that the holes in the metal plates under the 
engine needed to be enlarged to allow enough lateral movement for good 
alignment, this was done last week.  When the boat was delivered, the 
mechanic had pushed the engine hard to the side of it's allowable movement 
(not enlarging the holes) which meant that he likely could not get a full 
tighten down even when he thought he had.  The engine simply moved across 
when loaded.  The boat came from the factory that way, with the engine 
sitting high and with insufficient adjustability for alignment, suggesting 
some excessive design tolerances or quality control issues there.  The 
dealer did not pick this up on commissioning - and without detailed 
measurements and drawings it would have been hard for him to do so - hence 
all the grief.  I do fault the dealer mechanic for not realising that the 
engine was at the limit of it's movement when he first aligned the engine, 
or for doing nothing about it if he did realise.

Once the engine has been lowered it will be tested with the standard prop. 
If the knocking problem has been solved, the Kiwi Prop will be reinstalled 
and tested again.  We can then hunt for the water leak which causes the 
water pump to cycle every 30 seconds or so and numerous other details.

I am more hopeful now, but the proof will will be in the next round of 
testing.  Thanks to every one for their suggestions and support.  The dealer 
told me that he plans to call Gerry Douglas Mon to discuss the whole saga 
with him ( and presumably to discuss the ensuing warranty claim which will 
be significant).  For those who suggested withholding funds.  I did indeed 
keep a significant hold back, though the bare hull was paid for soon after 
delivery as I wanted title to the hull.  That holdback has not been paid 
(nor asked for).

Regards

Jerry Brown
#1137 Indigo
----- Original Message ----- 
From: "Rick Sulewski" <rsulewski at earthlink.net>
To: <C320-List at Catalina320.com>
Sent: Saturday, June 21, 2008 5:52 PM
Subject: Re: [C320-list] New Boat knocking noise


> Jerry,
>
> Sounds like the shaft may be flexing and banging against the hull.
>
> I had a similar sound back when I had a brass shaft and my engine was
> flip-flopping around before I discovered that the mounting studs had 
> worked
> loose. Whenever I accelerated quickly or whenever I would turn hard over
> under extreme throttle positions and with high hull speeds I would hear a
> repetitive banging noise.  I figured it was from the shaft flex 
> exacerbated
> by the shaft torque deflection permitted by the loose motor mounts. The
> sound would cease when I returned the wheel to center or lowered the 
> engine
> speed.
>
> That banging noise condition subsided, but did not entirely disappear when 
> I
> fixed the loose motor mounts. I had to replace the brass shaft a few years
> later with stainless shaft due to a line getting entangled in the prop, 
> and
> now I rarely hear the banging noise unless I am backing up under extremely
> hard acceleration when I need to quickly control the bow swing if I have a
> strong cross wind in the fairway.
>
> Wonder if your engine mounts are secure since the shaft and coupling are
> true. Since you have aligned the shaft, the only other consideration would
> be your strut flexing if it is loosely mounted or if it is misaligned
> relative to the shaft exit.
> .
> 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 Jerry Brown
> Sent: Saturday, June 21, 2008 7:29 AM
> To: C320-List at Catalina320.com
> Subject: [C320-list] New Boat knocking noise
>
> Suggestions Please
>
> Our new 320 is sitting at the dealer.  From the day of commissioning there
> has been a loud knocking sound from the stern whenever the boat is motored
> over about 2300 revs - we were told it would "settle down".  In two hours 
> of
>
> motoring from the dealer premises to our club the engine moved on the 
> mounts
>
> sufficiently that it jammed the engine cover which was free when we left 
> (I
> checked the oil before leaving).
>
> Initially the dealer "blamed" the Kiwi Prop that I supplied, and he
> installed.  He realigned the engine and told me to take the prop off and
> reinstall the standard two blader.  While still tied to the dock we tried
> the realigned engine (still fitted with the Kiwi Prop) as I was reluctant 
> to
>
> move the boat for fear of doing more damage.  The dealer also dove under 
> the
>
> boat to check that the prop was not fouled and that the blades were free.
> In that test the engine was moving around sufficiently to open up the
> stuffing box under load.  The dealer then thought that the initial 
> motoring
> and engine movement might have bent the propshaft.  The dealer then 
> arranged
>
> to have the boat moved (with minimal motoring) back to his premises.  The
> Kiwi Prop was removed and the shaft and coupling sent to a machine shop 
> for
> checking.  With the boat out of the water it was clear that the shaft was
> not aligned.
>
> The machine shop confirmed that the shaft and coupling are true.  The
> standard prop was then installed, the engine again realigned (the mechanic
> is getting lots of practice) and the boat put back in the water with
> assurances that all would now be good.  The opposite is true.  At 2300 
> revs
> the noise is more persistent and louder than with the Kiwi Prop.  A
> subsequent test by the mechanics with the engine covers off lead them to 
> say
>
> that, at the point where the noise starts, the motor can be seen to "move"
> sideways visually.  Another symptom is that when the engine is throttled
> back,  a relatively low frequency vibration passes through the hull which
> can be easily felt at the wheel.  The boat almost seems to be "shaking 
> it's
> hips"  There are no abnormal engine noises etc, no black smoke or any 
> other
> signs of engine problems.  It is smooth at idle and when revved in 
> neutral.
>
> Having confirmed that this is not a Kiwi Prop problem (i.e. my problem 
> from
> the dealers perspective) the dealers' next suggestion is that possibly the
> wrong engine mounting rubber blocks were installed from new.  That seems a
> possibility, but a pretty remote one.  I would welcome other theories as 
> our
>
> season is rapidly disappearing.
>
> Jerry Brown
> #1137 Indigo
> ----- Original Message ----- 
> From: <bruceheyman at cox.net>
> To: <C320-List at Catalina320.com>
> Sent: Saturday, June 21, 2008 2:40 AM
> Subject: Re: [C320-list] PHRF Racing Sails etc
>
>
>> Rick,
>> Our Sailmaker modified the pockets so that we can go with either full or
>> partial battens.  So far our favorite configuration is full for the top
>> two and partial for the bottom two.
>> Best,
>> Bruce
>> Somerset 671 SoCal
>> Sent via BlackBerry by AT&T
>>
>> -----Original Message-----
>> From: "Rick Evans" <ericstillwellevans at gmail.com>
>>
>> Date: Sat, 21 Jun 2008 02:46:26
>> To:C320-List at Catalina320.com
>> Subject: Re: [C320-list] PHRF Racing Sails etc
>>
>>
>> Thanks Bruce I was really curios on whether the dutchman would work loose
>> footed.
>>
>> I'm glad it will.
>> Sent via BlackBerry from T-Mobile
>>
>> -----Original Message-----
>> From: bruceheyman at cox.net
>>
>> Date: Sat, 21 Jun 2008 05:14:41
>> To:C320-List at Catalina320.com
>> Subject: Re: [C320-list] PHRF Racing Sails etc
>>
>>
>> Rick,
>> We have a loose footed main and use the dutchman system with no problems.
>> We like the loose footed main as it seems easier to trim the lower third
>> of the sail.
>> Bruce
>> Somerset 671 SoCal
>> Sent via BlackBerry by AT&T
>>
>> -----Original Message-----
>> From: "Rick Evans" <ericstillwellevans at gmail.com>
>>
>> Date: Fri, 20 Jun 2008 21:17:36
>> To:C320-List at catalina320.com
>> Subject: [C320-list] PHRF Racing Sails etc
>>
>>
>> I just started PHRF racing my c320 in Western Long Island sound. I was
>> wondering if anyone can give me some advise on cruising/racing sails they
>> may have upgraded to?
>>
>> I got some quotes from doyle but I am unsure what to go with.  My main
>> questions have to do with the main
>>
>> 1. Loose footed or not?
>> 2. Full battens or not?
>>
>> I love and want to keep the dutchman and want to know if anyone has used
>> it
>> on a loose footed main
>>
>
>