F25 Portable 12V Output

[F25Portable]

Good Morning Everyone,

I recently became the proud owner of a manual start, manual trim F25 Portable. I've been beyond impressed with this motor but I am scratching my head a bit on one thing and my Google-fu must not be up to snuff because I am having NO luck finding anything out about the 12v system on this motor.

I know these new F25's have a 16A alternator and I assume the electric start models come with a pair of battery cables but the manual start version, to no real surprise comes bare. I've been scouring the Yamaha website, my owners manual, random google searches, everything to see the proper way to add a pair of cables to this motor. I'm looking to charge a 12v battery for running a fishfinder, maybe one of those 12v plug in coolers, some lights, etc.

Anyone have one of these motors and can point me in a direction? If I go on the Australian Yamaha site it makes reference to some sort of battery charging kit but I can't find a part number there either.

Thanks in advance!

[boscoe99]

What is the complete model identity. All F25's are not the same.

If you are not in the US then the complete engine ID would be helpful.

[F25Portable]

Hello! thanks for the quick reply!
I'm in Canada, my F25 is a F25LMHC (Manual Start, Manual Tilt/Trim, 20" Shaft).

I believe I stumbled across an older post on this forum that seems to indicate I need to buy a rectifier/regulator off an electric start model. I wish Yamaha made this more apparent when purchasing the motor as I might have just gone with electric start even though I didn't want the extra weight.

I believe I need to purchase 6FM-81960-10-00 while my motor currently has 6FM-81960-00-00

[panasonic]

Looking at the parts for a 2021 F25 manual start it looks like you will need a regulator and wire harness to charge a battery, found under "optional parts"

As Bosce said you really need to supply the proper identification of the motor for a definite answer.

Good luck

[F25Portable]

Sorry for the delayed replies everyone, my account must be flagged because I'm new and my posts wait for someone (a moderator I'm guessing?) to approve them. I answered the model number with my first reply.

Thanks for the help both of you, this points me in the right direction!

[boscoe99]

As noted by panasonic, the parts catalog is showing what appears to be the components required so that the motor can charge a battery.

But I am a bit confused. The service manual shows a rectifier/regulator as being on both your model and the electric start model. A quick visual inspection can confirm if you need that part or not. If needed, buy it. If not needed, use what you have.

[F25Portable]

As noted by panasonic, the parts catalog is showing what appears to be the components required so that the motor can charge a battery.

But I am a bit confused. The service manual shows a rectifier/regulator as being on both your model and the electric start model. A quick visual inspection can confirm if you need that part or not. If needed, buy it. If not needed, use what you have.

When I go on the Yamaha part site, it shows two different regulator/rectifiers. Mine definitely HAS a rectifier on it when I pop the cowl, but according to Yamaha it is a different rectifier/regulator than the electric start models.

My model uses: 6FM-81960-00-00
Electric Start models show: 6FM-81960-10-00

I wish I knew someone with an electric start F25 because I'd love a picture of their wiring. My engine has a fairly large diameter red wire is dead-ended in the harness so it makes me think it already has an 12v output and I just need the harness but then I find that there are different part numbers and it has me scratching my head. I'm taking the boat out this weekend and am going to bring a voltage tester to see what the red wire is outputting. Even if it doesn't deliver the full 16A these are supposed to have, I don't need much to keep a 12v battery topped up for a fish finder.

[boscoe99]

Does the red wire come from the rectifier/regulator? I am guessing that it does.

Cobble together your own battery cables and connect the red lead to a battery. Also a ground lead as well.

Do you have a clamp on ammeter? If so, see if you can measure current flow to the battery.

[boscoe99]

[F25Portable]

boscoe99 Thank you so much for that diagram! That will make life a little less guesswork and a bit more pointed.
I have an amp clamp and a volt meter so I'll rig up a harness and make some tests. Even if I only get 1-2A (as opposed to 16 from the "proper" reg/rectifier I'm probably fine as I can't imagine a Garmin Striker 5 burns all that much juice and thats all I'm really powering off the battery.

Thanks again for the help!

As an off topic question? Do you know how long new members need to have each post approved manually? I answered you I believe on Friday but it wasn't approved until this morning. I just don't want anyone thinking I'm being slow to respond to such help people.

[boscoe99]

I have been here for years now and some of my posts are held for approval. It is all a mystery to me.

[F25Portable]

Well I can say that the rectifier IS needed as well.
Even though the manual start rectifier has a red battery lead, it does not output anything. I'm ordering the rectifier now.
Kinda wish Yamaha was more clear on this when you order these motors, they advertise 16A of electrical power but DON'T mention that the manual start engines don't actually have any way to output it as they come from the factory and by the time you buy the rectifier and harness you might as well have just bought the electric start model.

[F25Portable]

Just wanted to give a final follow up in case anyone else ends up in this scenario, they will have a complete part list to add battery charging ability to the newer F25 Portables with manual start.

You need to purchase the rectifier. The harness from the rectifier to the red output lead is the same but the manual start rectifier has no 12V output. I also reccommend buying the Yamaha harness to go from the 12v lead (and GND) to your battery. It includes a fuse and packages nicely into the motor. I could have cobbled something up myself but the factory looming is nice and tidy.

Part numbers:

Rectifier: 6FM-81960-10-00
Harness: 6FM-81949-00-00

Slightly annoying, because the part cost is higher than just buying the electric start model but at the same time my motor is still about 10-15lbs lighter then an electric start model so.... coin toss for portability reasons.

I can confirm the motor now puts out ~14v at idle and 14.3 at anything off idle. I only have a livewell pump and Garmin striker 5 CV running off it but its working great now!

Thanks everyone for your information!

[boscoe99]

Thank you for the feed back.

[kkiriak@gmail.com]

Searching to do the same, getting the battery charged from non-electric F25G model, I came across this thread which confirmed what I had in mind after parts catalog evaluation. I'm ordering those parts confidently today!