[C320-list] Tach reads only 3000 rpm at full throttle

[brucestanley]

My 1st thought would be 'Growth/Barnicles' on your Prop?
Bruce S
Sydney

----- Original Message ----- 
From: "Jim and Stacey" <bredar-sewell at comcast.net>
To: "'C320-List'" <c320-list at catalina320.com>
Sent: Wednesday, August 29, 2007 10:18 AM
Subject: [C320-list] Tach reads only 3000 rpm at full throttle


>I have a 3GM in my 2003 C320, Hull no. 937.   I have 300 hours on the
> engine.   Full throttle has always yielded a tach reading of just over 
> 3600.
> Yesterday I noticed that with the throttle full forward, the tach reads 
> only
> 3000 rpm.     What gives?   I don't have a keen enough ear to say whether
> the engine sounds like it is actually at 3600 even though the tach says
> 3000.    Thoughts and suggestions appreciated.
>
> Jim Bredar, "Ranger", C320 No. 937, Oxford, Maryland
>
>
>
> -----Original Message-----
> From: c320-list-bounces at catalina320.com
> [mailto:c320-list-bounces at catalina320.com] On Behalf Of brucestanley
> Sent: Tuesday, August 28, 2007 5:42 PM
> To: C320-List
> Subject: Re: [C320-list] calibration of my Tach
>
> Thanks Jeff
> your explanation is appreciated.
>
> BruceStanley
>
> ----- Original Message ----- 
> From: "Jeffrey Hare" <Catalina at thehares.com>
> To: "'C320-List'" <c320-list at catalina320.com>
> Sent: Wednesday, August 29, 2007 12:24 AM
> Subject: Re: [C320-list] calibration of my Tach
>
>
>> The Yanmar 3GM series engines use a pickup on the flywheel to handle the
>> Tach instead of the terminal on the alternator, so those with the 3GM
>> engine
>> don't usually have any re-calibration necessary when changing 
>> alternators.
>> Given that you probably have the 3YM engine, it appears that they aren't
>> using the flywheel pickup anymore in favor of the Tachometer terminal on
>> the
>> back of the Alternator like they do for the other non-yanmar engines on
>> the
>> C320.
>>
>> -Jeff
>>
>> -----Original Message-----
>> From: c320-list-bounces at catalina320.com
>> [mailto:c320-list-bounces at catalina320.com] On Behalf Of brucestanley
>> Sent: Tuesday, August 28, 2007 3:14 AM
>> To: C320-List; oldman1030 at hotmail.com; sthompson at toad.net
>> Subject: [C320-list] calibration of my Tach
>>
>> Hi All
>> re: the calibration of my Tach after I switched from the Hitachi 60Amp
>> to an older Hitachi 80Amp. The 80amp Alt produced far higher Tach
>> readings.
>> This I solved by a terminal wiring alteration to the back of the Tach.
>> This terminal was straight forward. I did this approx 14 mths ago.
>> I am far from an electronics expert, but that is exactly what I did.
>> I am a DIY advocate and love doing most of my own work on my Yacht.
>> Parts I do not understand and parts I break. I still enjoy the journey.
>>
>> BruceStanley C320#1084
>> Sydney Australia
>>
>> ----- Original Message ----- 
>> From: "Chris Holt" <oldman1030 at hotmail.com>
>> To: "C320-List" <c320-list at catalina320.com>
>> Sent: Monday, August 27, 2007 9:48 PM
>> Subject: Re: [C320-list] Club Racing the C320
>>
>>
>>> That was what I had thought also.  I also did not experience any
>>> perceived
>>
>>> change of my tach readings after the installation.  I have a 1997 with a
>>> 3GM motor.
>>>
>>> Bruce,  maybe you experienced this because of a different setup on the
>>> 3YM
>>
>>> engines.
>>>
>>> Chris
>>>
>>> ----- Original Message -----
>>> From: "Scott Thompson" <sthompson at toad.net>
>>> To: "C320-List" <c320-list at catalina320.com>
>>> Sent: Sunday, August 26, 2007 7:09 PM
>>> Subject: Re: [C320-list] Club Racing the C320
>>>
>>>>I don't know about the newer or older boats, but on my 1999 boat there 
>>>>is
>>>>no need to recalibrate the tach when switching alternators.  That's
>>>>because on the Yanmar 3GM series of engines, the tachometer reading 
>>>>comes
>>>>from a sensor in the flywheel housing that counts the flywheel teeth as
>>>>they rotate past.  In these engines tachometer calibration has nothing 
>>>>to
>>>>do with the alternator.
>>>>
>>>> Scott
>>>>
>>>> brucestanley wrote:
>>>>> Hi Stephen
>>>>>
>>>>> re Kiwi Prop and Engine Revs
>>>>>
>>>>> Fantastic Lady's 3YM30 cruises at 2100 to 2900 rpm.
>>>>> Depending on tide/wind, this delivers 4+++ to 6+ knotts.
>>>>> Occasionally I advance the Revs to 3000 and 3300rpm.
>>>>> Sometimes to 3500++RPM for only a few minutes.
>>>>> Revs are a bit of a lottery, in that one hopes the Catalina Tach is
>>>>> calibrated accurately.
>>>>> I am reasonably sure they are close to correct on Fantastic Lady.
>>>>> Note: if you change your alternator you have to make a change at the
>>>>> Tachometer.
>>>>> I have an 80amp Hitach Alternator and have made this change.
>>>>>
>>>>> You must be able to Rev to 3600RPM (Yanmar's requirements).
>>>>>
>>>>> Hope this helps
>>>>>
>>>>> Bruce Stanley
>>>>> C320  #1084 Fantastic Lady / Sydney Australia
>>>>>
>>>>> ----- Original Message ----- From: "Stephen Cox" <scox at timmin.com>
>>>>> To: "'brucestanley'" <brucestanley at optusnet.com.au>
>>>>> Sent: Thursday, August 23, 2007 1:30 PM
>>>>> Subject: RE: [C320-list] Club Racing the C320
>>>>>
>>>>>
>>>>>> Thanks Bruce.
>>>>>>
>>>>>> What revs can you get your motor up to with this prop?
>>>>>>
>>>>>> Stephen Cox
>>>>>> Canberra
>>>>>>
>>>>>>> -----Original Message-----
>>>>>>> From: c320-list-bounces at catalina320.com
>>>>>>> [mailto:c320-list-bounces at catalina320.com] On Behalf Of brucestanley
>>>>>>> Sent: Thursday, 23 August 2007 8:20 AM
>>>>>>> To: C320-List
>>>>>>> Subject: Re: [C320-list] Club Racing the C320
>>>>>>>
>>>>>>> Stephen
>>>>>>>
>>>>>>> My Kiwi prop is 16.5"
>>>>>>> and The factory has set the angle at 22 degrees.
>>>>>>> This pitch setting of 22degrees is based on the engine you have.
>>>>>>> Mine is the Yanmar 3YM30.
>>>>>>>
>>>>>>> Bruce Stanley
>>>>>>> C320  #1084 Fantastic Lady / Sydney Australia
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>>
>>
>>
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