Converting a manual start outboard to electric - Yamaha F40

tod osier

tod osier

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I'm starting to accumulate the parts and knowledge to convert my Yamaha F40 to electric start. I think it is very doable for several hundred dollars with a mix of new and used parts.

What my question for the brain trust is that I'm wondering about the utility of going full out and adding the charging circuit to the motor. The charging circuit addition requires a different stator and a rectifier & regulator and MAYBE a new wiring harness (I think I should be able to add what I need to the current harness, but I'm not that deep into the weeds yet, the new harness is $400). So with those parts, new I'm looking at 400 (maybe 800) extra or a couple hundred if used and more work (and uncertainty if using used parts vs new). I'd probably buy new parts for electrical components like the rectifier and regulator to be sure they work.

How important is the charging circuit to keep the battery topped off if I'm keeping a large deep cycle/starting battery (100 AH) topped off on a trickle charger when the boat is not in use (I do that already)? I'll still have pull start as a backup. How many starts can you get off a larger battery without charging? My guess is plenty, but I'd like input.
 
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Tod,
Yes no maybe,,,,,,,,,,

If you can get the specs on the charging output at various engine RPM's it would help in your decision. My best guess; probably not needed and may not be that much benefit.

As an example; I have a 25 hp Yamaha on my BBIII and I can't off the top of my head give you the charging specs. When hunting, I make short runs (under 2 miles) and leave lights, and sonar on a lot. When fishing I make even shorter runs with more stops and starts. I've never had to use my rope pull backup, but I do see my battery voltage dropping over the day. I will say that during a top end run of 3 miles back to the ramp, I can watch my battery voltage increase during that run. I do wonder if what I'm seeing is just a "surface" charge.

That said, I hook up a portable charger to the rig about every other or every third trip just to be safe.
 
Huntindave McCann said:
Tod,
Yes no maybe,,,,,,,,,,

If you can get the specs on the charging output at various engine RPM's it would help in your decision. My best guess; probably not needed and may not be that much benefit.

As an example; I have a 25 hp Yamaha on my BBIII and I can't off the top of my head give you the charging specs. When hunting, I make short runs (under 2 miles) and leave lights, and sonar on a lot. When fishing I make even shorter runs with more stops and starts. I've never had to use my rope pull backup, but I do see my battery voltage dropping over the day. I will say that during a top end run of 3 miles back to the ramp, I can watch my battery voltage increase during that run. I do wonder if what I'm seeing is just a "surface" charge.

That said, I hook up a portable charger to the rig about every other or every third trip just to be safe.
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Thanks, Dave. My suspicion is that I'll be fine without, especially since I can have a large battery and keep it charged all the time. The main reason is getting the thing started the first time on those cold days (20-30 pulls of that sucker is pretty bad - usually it isn't a problem to get started, but once in a while). Also hunting with Gus, it would be nice if he could start the boat. There is no way he is going to be able to pull start that thing if the boat stalled out when he was motoring by himself when I was out of the boat.

I can look up the charging output to see what it looks like good point. I can estimate the starter load too.

I have a new (used) flywheel on the way and if I'm going to change it out that is the time for a stator change. I'm assuming that the magnets on the untoothed flywheel that I have and the toothed flywheel match, otherwise I'll need the new stator too to match and I'll be along on my way to a charging circuit.
 
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Tod, I have the charger in my Yamaha 50 2 stroke. I use a motorcycle battery to start the motor and run all the cabin and running lights. I hunt in NJ so its pretty cold here in late December and January. I charge the battery at the beginning of the year and not again until the off season. Its very nice to have.
 
tod osier said:
The main reason is getting the thing started the first time on those cold days (20-30 pulls of that sucker is pretty bad - usually it isn't a problem to get started, but once in a while). Also hunting with Gus, it would be nice if he could start the boat. There is no way he is going to be able to pull start that thing if the boat stalled out when he was motoring by himself when I was out of the boat.
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Holy crap, I'd have to put my rig back on the trailer. No way I'm able to yank on a boat motor that much anymore. I have a 25hp.Merc hanging on a stand in the garage just for a back up motor. (had it on hand, paid for, no need to sell) It was a pull start and I converted it to electric, just because I wanted electric, if I ever actually ended up needing the back up motor. I was able to do the conversion with used parts for a total of 250 dollars.
Good point concerning Gus. Last summer I started introducing my then 9 year grandson to basic boat operation. Hopefully, if something might happen while we are out fishing, he may be able to get us back to the ramp.
 
Not much to add on the technical side, but I've been considering converting my Merc 25 two stroke to electric start too. Yanking on the pull start 10-20 times after the motor has been sitting for a few months is no longer much fun at all.
 
Huntindave McCann said:
tod osier said:
The main reason is getting the thing started the first time on those cold days (20-30 pulls of that sucker is pretty bad - usually it isn't a problem to get started, but once in a while). Also hunting with Gus, it would be nice if he could start the boat. There is no way he is going to be able to pull start that thing if the boat stalled out when he was motoring by himself when I was out of the boat.
Click to expand...

Holy crap, I'd have to put my rig back on the trailer. No way I'm able to yank on a boat motor that much anymore. I have a 25hp.Merc hanging on a stand in the garage just for a back up motor. (had it on hand, paid for, no need to sell) It was a pull start and I converted it to electric, just because I wanted electric, if I ever actually ended up needing the back up motor. I was able to do the conversion with used parts for a total of 250 dollars.
Good point concerning Gus. Last summer I started introducing my then 9 year grandson to basic boat operation. Hopefully, if something might happen while we are out fishing, he may be able to get us back to the ramp.
Click to expand...

It is often/usually a one or two pull motor, but sometimes when it is cold it is balky.
 
I converted over my E-Tec 25 to an electric start too about 3 years ago. I have yet to put a charger to my battery. The motor should have a magneto system that should charge the battery while the motor is running. One thing that helped was I changed over all my lights to LED so they draw less when on. I also got the smallest/highest CCA optima battery I could find. 900CCA for the first 20 seconds, plus it weighs only 24-25lbs
 
tod osier said:
It is often/usually a one or two pull motor, but sometimes when it is cold it is balky.
Click to expand...

I get that way too! [cool] Don't even want to know if an "electric start stimulator" could be integrated with an alarm clock. [huh]
 
I did a evinrude 25 years ago out of the scrap pile at the marina. Cost was ok and just took a while with two polish guys working together. Was well worth it in the mornings and freezing weather.
 
Tod,
Great question, and I'm enjoying watching the tread. Every now and then I'll check out "kits" on Ebay to convert my 25hp yamaha 2-stroke to starter; there have been a few takeoffs from older used motors and perhaps some Chinese clone new parts sets. The kits usually contain harness, flywheel, starter, and some other electrical parts. My motor has really started well throughout this summer (amazing what freshly cleaned carbs, new plugs, and giving the primer bulb a good hard squeeze will do), but am waiting to see if it get's cranky winter. Always thought it would be nice to have a charging system on the motor, and am curious if you still need to top off the battery. At least the pull start would still be there if needed.

Please let us know if you convert and how it works out.

v/r
Bill
 
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