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

[Scott Thompson]

I'm a bit confused if you reached 4000 during the sea trials but now 
can't get above 2700.  The Yanmar 3GM30F, like most diesels, has a speed 
limiter built in, and shouldn't run above 3400 at all, and should only 
be run that hard for an hour at most.  Most likely you have a bad tach 
connection somewhere, or a bad tach sensor.

Another thing you might check if you aren't reaching full RPM is the 
fuel supply.  A clogged fuel filter would prevent you from reaching full 
cruising RPMs.  If the tank is dirty or you take on a load of bad fuel 
this can cause trouble in short order.

pjaarch wrote:
> I did just sand and paint the bottom.  I am loased down as I am 
> curreinly cruising but so are the other boats I am with.  During the sea 
> trail we did run the boat at near 4000 RPM which makes me believe the 
> boat is under proped.  He told me you could run the boat all day like 
> that but I was lead to believe that you should run it only at 80% of the 
> rating.
> 
> Paul Adison
> C320 #722
> 
> ----- Original 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