[C320-list] New Boat knocking noise

[Robert Seastream]

It almost sounds like your engine mounts are extremely loose.  It also  
sounds like your dealer just wants to close the deal and get rid of  
you and the boat.
I'd call Gerry Douglas at Catalina Yachts, tell him briefly of this  
(including the dealership name & info), and tell him you'd like to  
send him a followup email with more details.  I'd also make it known  
to all parties that I'm considering washing my hands of this dealer  
and boat (if possible), taking my business elsewhere.

I feel for you; you simply want to go sailing, and time's running  
out.  However, with the sort of money involved, this dealers' attitude  
and approach is hideous.

Bob Seastream
Intuition # 906


On Jun 21, 2008, at 7:28 AM, Jerry Brown wrote:

> 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