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

[allan.field at comcast.net]

Jim - I had Sea Shadow out of the water a few weeks ago after being in only about 7 months.  The prop was covered with barnacles.  This seems to be a particularly bad year for the little critters on the Bay.

The C320 Association has a Toolbox Loaner Program of which I am the custodian.  Linda and I probably will make at least one more trip to Oxford this Fall.  When we do, I will try to remember to bring the optical tachometer with me so that you can check your tach.  When I used it on Sea Shadow, I found that the boat tach was spot-on.  Otherwise, I can ship it over to you as part of the program.

Allan S. Field
Sea Shadow - #808
Columbia, MD

-------------- Original message -------------- 
From: "Jim and Stacey" <bredar-sewell at comcast.net> 

> Thanks for the responses. I guess its time to grab the scraper and mask 
> take a little dive. I'll report back. Jim Bredar, "Ranger", C320 #937 
> 
> -----Original Message----- 
> From: c320-list-bounces at catalina320.com 
> [mailto:c320-list-bounces at catalina320.com] On Behalf Of Karl Mielenhausen 
> _/) 
> Sent: Wednesday, August 29, 2007 11:21 AM 
> To: C320-List at catalina320.com 
> Subject: [C320-list] FW: Re: Tach reads only 3000 rpm at full throttle 
> 
> 
> Jim, 
> 
> I concur with Chris. I had the exact same problem (could not develop 3600 
> rpm). Also was running hotter than usual, but then again our river is 
> currently 85F. Cleaning the prop of barnacles solved both problems. 
> 
> 
> 
> Karl Mielenhausen 
> 
> 2000 C320 Hull#690 "Silver Lining" 
> 
> New Bern, NC 
> 
> http://pages.suddenlink.net/kmielen/ 
> 
> From: Chris Burti [mailto: clburti at gmail.com] 
> 
> To: c320-list at catalina320.com 
> 
> Date: Tue, 28 Aug 2007 22:28:46 -0400 
> 
> Subject: Re: [C320-list] Tach reads only 3000 rpm at full throttle 
> 
> 
> 
> Barnacles on the prop will do that fairly suddenly.On 8/28/07, Jim and 
> Stacey wrote:> 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" 
> > To: 
> "'C320-List'" > 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" 
> > > To: "C320-List" > > 
> 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" > >> 
> To: "C320-List" > >> 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" > >>>> To: 
> "'brucestanley'" > >>>> 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> >>>>>>> 
> >>>>>> >>>>>> >>>>> >>>>> >>>> >>>> >>> >>> >> >> >> >> >>>>>-- Chris 
> BurtiFarmville, NC 
> 
> _______________________________________________ 
> 
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