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Message |
    
kim hartshorn
Member
Username: kimhartshorn
Post Number: 15
Registered: 08-2010
| | Posted on Tuesday, July 17, 2012 - 11:20 am: | 
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The '53 Viking I am trying to get in the water has the original 6V GAF autolite generator mounted on the model 620 engine. The previous owner had this set up with a 12V battery and 12V coil...he told me when I bought the boat that he thought it was a 12V generator...but it is not. He also told me that the boat lost power at around 1000 rpm which made me think there was an electrical issue. My guess is that on the cut-in for the generator (which is listed as 975 rpm) that the 12V battery at that point was attempting to run the generator as a motor and the additional load was what caused the drop in power. (since before cut-in the battery was handling the ignition) Does this sound right?
So I am investigating options and looking for opinions. I am leaning towards going back to a full 6v system although that would mean getting a 6v coil and a fairly expensive 6v golf cart battery. Converting the 3 brush generator to a 2 brush 12v which seems problematic. Mounting a 12v alternator and finding a different way of driving the water pump. Shimming a VW 12V generator (which has a through shaft) to fit the mounting ring and then adapting the shaft to the water pump.
Any opinions?
One more question, the manual says that adjusting the third brush will incrase or decrease the charging rate...is this done through increasing the voltage output? Can the voltage output be adjusted above 12V in this manner?
thanks in advance for all suggestions. |
Douglas J. Beattie
Member
Username: gannet
Post Number: 12
Registered: 04-2005
| | Posted on Saturday, July 21, 2012 - 09:00 am: |
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That generator will charge your 12v battery. Google brought me detailed information on adjustment, which is critical. I don't think your gen is trying to be a motor; 975 rpm is when the gen starts to charge(gen rpm, not engine rpm.) IIRC you want to limit charge to 10amps and never run engine if gen not connected to battery. |
kim hartshorn
Member
Username: kimhartshorn
Post Number: 16
Registered: 08-2010
| | Posted on Saturday, July 21, 2012 - 01:38 pm: |
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Thanks for the reply Douglas. Do you have a link for those instructions? Also my original post mis-identified the generator as GAF...it is actually a GFA model.
One more question, if I can adjust the third brush to get me 13-14V output how do I deal with the cut-out switch that will not charge the battery if the battery is above 6V? Simply remove it out of the circuit? |
Douglas J. Beattie
Member
Username: gannet
Post Number: 13
Registered: 04-2005
| | Posted on Monday, July 23, 2012 - 06:34 pm: |
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The third brush adjusts amperage. not voltage. The cut out doesn't seem to care what the voltage is, but removing it will cause serious overcharing. |
kim hartshorn
Member
Username: kimhartshorn
Post Number: 17
Registered: 08-2010
| | Posted on Saturday, July 28, 2012 - 09:55 pm: |
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Well, I am more than confused with the electrical in this boat. Additional information I have discovered...the previous owner had the battery and the coil installed negative ground although from the gray manual and the Generator specs it was originally positive ground. I am assuming that the polarity of the generator had been changed but that is just an assumption. Also the coil had been replaced with a 12V coil. What else could be causing the drop in power at the cut-in speed of the generator? To me it sounds like voltage is dropping to the coil at this point. Why would voltage drop when the generator kicks in? |
Douglas J. Beattie
Member
Username: gannet
Post Number: 14
Registered: 04-2005
| | Posted on Monday, July 30, 2012 - 07:38 pm: |
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Why don't you connect the coil to a seperate battery, thereby isolating the charging system from the ignition system. Measure the diameters of the pullies on the engine and gen to figure out when the gen is at 975 rpm. It will most likely be well below 1k eng. rpm.
You might also check the distributor centrifical advance and the fuel pump. |
