Yamaha 6 horse 12 volt output to battery?

[bjadams]

Hi All,

I have a 1993 Yamaha 6 horse engine that has 2 unconnected wires on it putting out 12 volts. I'm wondering if I can hook this directly to a battery for charging, or do I need to run it thru a voltage regulator first? I will be running 2 or 3 high wattage lights, a sounder/gps (gpsmap 235), and an aerator. I am thinking of using a new atv battery I bought that was the wrong size. It will take up less space on the jon boat, but will need on-board charging due to it's size.

Thanks all and hope to hear from someone,
bja

 

[bjadams]

Re: Yamaha 6 horse 12 volt output to battery?

Can anyone help me with the question above?
Thanks,
bja

 

[Gagarin737]

Re: Yamaha 6 horse 12 volt output to battery?

If the color of both wires is yellow than the output is AC. You need DC. On most smaller engines the rectifier is an option. Will cost around $100,-

 

[Wee Hooker]

Re: Yamaha 6 horse 12 volt output to battery?

I would put a voltage meeter to the leads BEFORE I connected it to any battery.
Additionally, a service manual ( or a trip to the Yamaha board) should get you specs on the output.

 

[bjadams]

Re: Yamaha 6 horse 12 volt output to battery?

Hi Guys,
Thanks for the replies. Oddly enough both of the wires are green and neither has a color stripe. I can't find a used manual and I'm guessing it would be 1/3 of what the motor is worth. It tested AC so I'm thinking about putting a rectifier/regulator off of a old motorcycle on it.
Thanks again,
bja

 

[Gagarin737]

Re: Yamaha 6 horse 12 volt output to battery?

I guess it is yellow at the four stroke engines, green at the two stroke engines;

Color Coding Yamaha

Good luck!

 

[bjadams]

Re: Yamaha 6 horse 12 volt output to battery?

Just to follow up:

I pulled the retifier / regulator off of a junk quad I had laying around. I believe it was a 1985 trx250 honda. It had 3 wires input, and 3 wires output.

I tied 2 of the yellow input wires together on the rectifier and connected them to one of the green wires on the outboard. I then tied the remaining 1 yellow rectifier and the one green outboard wires together.

At this point I started testing with the meter. I tested the red and black wires (battery hookups) coming out of the regulator while running the outboard. Oddly enough it converted the yamaha output to dc, but it was not regulated. It would go way past 25 volts at WOT. So close, but no go.

I then hooked the battery wires up to a battery and tried again. Still way too much voltage. I had read that the green wire coming out of the rectifier was for aux power on the honda. So, I hooked a light up between the green output on the regulator to the battery ground. Voila, the light lit and it was regulated. After that, I tried just hooking the green regulator output to battery ground. It was still regulated good solid voltage at all mid to upper rpm's. At idle, the yamaha is not putting out 12 voltages, once it hits about 14.2 tho, it never increases.

You can search for trx250 regulator on google and see what it looks like. Coming off a junk bike, I had the luxury of getting both the bike side plug and the regulator plug so I'll be able to simply unplug the regulator if I need to.

It's going to be very nice to have a fishfinder, lights, etc on my little jon boat.

Thanks for the help / suggestions and I hope this helps someone else.

bja