[C320-list] [SPAM] Re: Boat Speed

[Scott Thompson]

Under propped would cause high RPMs but it should not cause it to run 
hard.  Instead it sounds like a fouled bottom/prop or a heavily loaded 
boat.  Could also be a misaligned shaft or worn cutless bearing causing 
lots of vibration.

Rick Evans wrote:
> Sounds like under propped
> Sent via BlackBerry from T-Mobile
> 
> -----Original Message-----
> From: "pjaarch" <pjaarch at verizon.net>
> 
> Date: Tue, 07 Jul 2009 07:19:59 
> To: <C320-List at Catalina320.com>
> Subject: Re: [C320-list] [SPAM] Re:  Boat Speed
> 
> 
> I sanded the bottom and cleaned the prop.  We are cruising now so the boat 
> is loaded down but so are the others I am with.  I did notice that during 
> the sea trial, the boat was run at near 4000 rpms for just a minute.  If the 
> engine is rated at 3400 rpms, should the engine run that much faster?  It 
> could be a tach problem, but the engine sounds right at 2700-2800.  Over 
> that, it sounds like its really working hard.  The boats I am with are all 
> running about 2400 to stay with me which is well under there cruising speed.
> 
> Paul Adison
> C320 #722
> "Rough Draft"
> riginal Message ----- 
> From: "Rick Evans" <ericstillwellevans at gmail.com>
> To: <C320-List at Catalina320.com>
> Sent: Monday, July 06, 2009 8:08 PM
> Subject: [SPAM] Re: [C320-list] Boat Speed
> 
> 
>> Paul
>>
>> I have number 724 and last year with a crappy bottom she would still get 
>> 5.5 sometime 6knts depending on wind, current etc.
>>
>> This year I scraped all old paint put on VC offshore and wet sanded with 
>> 400grit and took a wire brush to the prop to insure a smooth surface. The 
>> other day I was out in a slack tide and at around 2700 she was doing 
>> 7knts. This is through the water not over ground on gps. I only have a 2 
>> blade prop.
>>
>> In any event dirty bottoms and gunked up props could easily be the cause 
>> of slow speeds. When I first bought the boat the surveyor took it for a 20 
>> mile jaunt to pull her out of the water he said she wouldn't do better 
>> than 5knts. When they pulled her the bottom was a mess and the prop looked 
>> like a barnacle factory.
>>
>> If you just bought her was she surveyed? Was the bottom and prop clean?
>>
>> Rick 724
>> ------Original Message------
>> From: pjaarch
>> Sender: c320-list-bounces at lists.catalina320.com
>> To: C320-List at Catalina320.com
>> ReplyTo: C320-List at Catalina320.com
>> Subject: [C320-list] Boat Speed
>> Sent: Jul 6, 2009 5:39 PM
>>
>>
>> I just purchased my 320 several weeks ago and am concerned about the boat 
>> speed while under power.  I have a 3GM30F and cruise at about 5.4 knots at 
>> 2700RPMs.  It seems slow to me.  I am currently cruising with other boats, 
>> a (hunter 28, beneteau 331, and an Irwin 38.)  They all cruise easily 6 
>> knots at 2700 RPMs and I can't keep up.  I have a 3 blade prop.  Could I 
>> be under proped?  What is the cruising RPMs for the boat?  I have no ID 
>> plate on the engine block.  I assume it is rated for 3400.
>>
>> Paul Adison
>> C320 #722
>> "Rough Draft"
>>
>>
>> Sent via BlackBerry from T-Mobile 
> 

-- 
Scott Thompson
Surprise, #653