[Public-list] Propeller question

[Gordon Laco]

No worries about being long winded... This is stuff I know nothing about and
need to learn!

Gord #426







> 
> 
> Hi John,
> 
> What you "may" need as was recommenced at a "Seminar on Boat Electronics"
> that I recently attended is to change the voltage regulator in the
> alternator to an External Marine regulator.
> 
> 
> Anyone ever heard of this?
> They can be adjusted to slightly vary the voltage.
> You have to be careful varying the voltage so you don't cook your batteries.
> 
> The operating voltage area or envelope we operate in is very small and it
> does not take much to cause problems.
> Without going into a detailed explanation about the difference between a
> regular "auto" voltage regulator and a "Marine External" regulator, you may
> want to look in to this.
> 
> I changed my 13 X 7 prop on my Atomic 4 to 11 X 7 and had it balanced.
> I would rather have gone to a smaller change of 12 X 7 but the prop was in
> bad shape on the ends, it was cheaper to cut the ends off and reshape and
> balance at the time.
> 
> The engine now runs at 1800 rpm in flat water at 6.2 knots.  The engine also
> comes up to higher rpm a little faster than before but this does not help
> charging the engine that much.
> 
> I have 2 batteries:
> 
> One deep cell (house bank) and one regular truck starting battery.
> Deep cells discharge slowly, and take longer to recharge, than regular
> batteries. This is why a Marine External Voltage regulator is better for
> boat setups.
> 
> Another problem is that we just don't run the engine that much, we go
> sailing!
> That is another reason the batteries don't get charged much!
> 
> If you have the original wiring harness on you Atomic 4 you may want to
> change a bit of it. The charging side especially. The large orange and red
> wires in the rubber plug near the engine.
> 
> My boat had an Amp meter in the engine panel and I changed it to a voltmeter
> and I replaced the wiring on the charging side of the circuit.
> 
> In order to have an amp meter (amp meter must be "in series" with charge
> current) in your panel the wire runs all the way up to one side of the Amp
> meter and back to the engine. There can be a voltage drop in this setup.
> 
> Some say go to a higher rate alternator, especially if you have one of the
> old 35 amp alternators. This is an option as was discussed at this seminar
> but the instructor recommended the advantages of External Marine regulator.
> He also recommended changing the wiring to a more modern configuration.
> 
> The instructor gave out wiring diagrams and if anyone is interested, I could
> scan and email them.
> 
> 
> I hope this was not too long winded...
> 
> 
> 
> -bob
> #560
> 
> 
> 
> 


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