scott mcculloch 1960 40hp

[jamcc85]

battery wont charge? what are the reading from the coils supposed to be. their are three wires on the regulator one for each coil and the center one for the battery. does any one know how to test the regulator.

 

[F_R]

Re: scott mcculloch 1960 40hp

Are you sure you are looking at a regulator? Isn't it a rectifier? The original probably was a selenium rectifier, looks like a stack of crackers with spacers between them. It may have been replaced by a modern silicone diodes bridge rectifier, but I can only guess what they put in there.

Need more information.

 

[jamcc85]

Re: scott mcculloch 1960 40hp

yes it looks like a stack of crackers what do i do next. how do io tell if it is bad. and what do i replace it with

 

[F_R]

Re: scott mcculloch 1960 40hp

Those were very inefficient when new. Want to know what I would do? I would go to Radio Shack and buy a #276-1185 bridge rectifier. Cheap, at less than $4.

Mount it somewhere on a heavy metal part in a cool area of the motor, to absorb heat. You will find four terminals on the rectifier. Two are marked AC or ~, and one is + and one is -. The yellow wires coming from the alternator coils go to the AC terminals. Ground the - one and connect the + to the positive battery cable.

http://www.radioshack.com/product/index.jsp?productId=2062584

 

[jamcc85]

Re: scott mcculloch 1960 40hp

if i install this what should the voltage readings be at the battery wheb the motor is running, what are the coils supposed to put out.

 

[F_R]

Re: scott mcculloch 1960 40hp

If the battery is fully charged before you start it, check the voltage across the battery. Then start the motor and the voltage across the battery will increase after it runs awhile. Don't worry about the exact numbers.

A battery is charged by forcing an electric current through it backwards. That means the alternator/charging voltage must be higher than the battery voltage, in order to force the backwards flow---the reason for the higher reading when charging.

Hope I didn't just make it too confusing for you. Just thought you might like to know.

 

[jamcc85]

Re: scott mcculloch 1960 40hp

no its not confusing i did not know that it charges backwards. so what should the battery have for voltage when it is fully charged i have seen a 12volt battery be anything from 12volts to 14volts fullly charged and as long as the battery is 12volts or higher it should start the motor just fine right? So if the battery is at 12volts the coils will read anything above 12volts?

 

[F_R]

Re: scott mcculloch 1960 40hp

I dunno what the official full charged battery voltage is, 12-point something, with no load on it. I never considered it really that important, but somebody will dispute that. Most regulated charging systems put out about 14.5 DC volts. Yours isn't regulated. If you check the coils' voltage while running with no rectifier, or not connected to a battery, they may go sky-high, even as much as 100 volts AC. That is why you must not run the motor with the battery disconnected--the high voltage will blow the rectifier. Of course if you check the coils voltage with everything connected, it will be the same as battery voltage, but AC. Well, almost. You have to allow for voltage drop across the diodes, and stuff like that. Now we are getting complicated again.

 

[jamcc85]

Re: scott mcculloch 1960 40hp

its not very complicated i replaced the rectifier with the one you told me to and it fixed the problem. with the motor just idling i have about 12.6volts and with the motor half throttle it has about 13 volts. that should be plenty to keep my battery charged? i put two new battery cables on it the battery was at 12volts and it barely cranks the motor. the other day before i left home i cranked the motor over just to make sure the battery wasnt dead and it cranked over just fine. When i got to the lake i put it in the water and it barely cranked the motor the drive was only about 15 min and nothing was left on, and that is the condition of the battery now. It has full voltage but the amps must be gone? becuase if i crank on it it will only drop about .1 volt. its odd

 

[F_R]

Re: scott mcculloch 1960 40hp

If you don't have any corroded battery cable connections, and the cables are adequate size, the starter is probably on its way out. They weren't the world's greatest starter to begin with, just barely adequate when new. Keep your voltage drop across the cables and connections as low as possible. Size matters with cables, skinny ones don't cut it.

 

[jamcc85]

Re: scott mcculloch 1960 40hp

i installed 4 gauge battery cables and the motor barley cranks until i hook up jumper cables to the car then it turns over just fine.

 

[unclepete2o]

Re: scott mcculloch 1960 40hp

Sounds like a battery not throwing out enough amps.... Does your motor have a starter selonoid? its worth a try to replace that before you replace a starter.

 

[jamcc85]

Re: scott mcculloch 1960 40hp

no solenoid and that is what i think of the battery to.

 

[jamcc85]

Re: scott mcculloch 1960 40hp

F R thank you for all your help and time. all your advice worked great now my battery is charging and i dont have to be woried about it going dead.