How to add electric start to a small outboard motor, DIY electric start on a Mercury outboard motor 

I was an electrical contractor for most of the 70’s, then EE for another 35, so electrical stuff is my gig! I’m glad you enjoyed the video! Thanks for watching!

Bob's Barn Workshop Bob, any way you have a part number or link to the 50A connector you used? I see similar products online but the one you’ve got looks bette quality that what my internet searches are bringing up. Thanks! And great video, very simplified way of doing it.

@@granio95 I got the Anderson SB50 connectors on a website called powerwerx.com here's a link to the page and connectors. I got all the connector waterproof covers here too. Make sure you get two terminals for each connector you use. I think I got the 50 CB, 20A fuse holder, 6 gauge wire here too. I think the 50A circuit was overkill, probably could use 8 or 10 gauge wire and reduce the main fuse to match the wire, 40A for #8 wire, 30A for #10. I included the link to the page below. Thanks for watching! powerwerx.com/anderson-power-powerpole-sb-connectors#/specFilters=129m!#-!307&pageSize=90&orderBy=0&pageNumber=1

See this post again, I found my paper with all the part numbers. Good luck!

I did a later video adding a charging coil to my motor which required me to run a separate wire from the rectifier diode back to the battery box, but it works fine!~ Good luck!

The switches have built in LED’s and current limiting, so just hook up the feed, load and neutral. I don’t remember where I bought them , probably eBay or amazon. I just searched for waterproof switches …. And the ones with the pilot lights came up. score! Thanks for watching!

I am actually at the lake for 4th of July week. Maybe I can open up the control box and show the details of how it goes together.

Well, from what I see you connected the 20A fuse to the load side of the 50A fuse. It only means that if anything on those parallel branches (bilge pump) were to dead short it could possibly blow both fuses. But if that happened wire jacket may start melting first. You would smell it, cheers.

It’s really not hard to build! Some 6ga wire for the primary wires to the starter relay from battery positive ( I put in a self reset 50 A breaker in between) to an Anderson 50A 2pole connector, to the starter, ground back through the Anderson connector and to battery negative the rest is just small wire to the relay coil (through a fuse first) through a momentary push button to battery negative. That’s it! I suppose I could build you one.? Want any other accessory switches? I have navigation lights and bilge pump

@@bobsbarnworkshop I watched your video a few more times and I think I can do it. I'll keep you posted. Thanks for getting beck to me!

@@theanglerboy I made a home made terminal crimper for the big connectors by drilling a hole in a piece of hardwood the same diameter as the terminal barrel, then split it through the center of the drill hole. Then I stripped the wire , put it in the terminal, laid it in the half hole and used a screwdriver and a hammer to make a nice firm indent to make the connection tight! Good luck! Sorry I didn’t film the actual construction. I bought the 12v relay at autozone for about $14, I had the big plastic battery box around the lake forever!

The flywheel and starter would be specific to the make and model of motor, however they use the same parts on a family of models, for example on a 20 and 25 hp. Starter motors fit many models. The relay and electrical parts are not specific, anything that meets the requirements. Hope that helps Thanks for watching

@@bobsbarnworkshop thanks mate we need more magivers around like this only vid i could find, i have a 12ft dinghy and a tiller 9.9hp 1990 mariner engine going to convert to steering wheel throttle control and electric start any help be amazing

@@nz2386 look at the flywheel for a ring gear with starter teeth. If you have that you’re well on the way! Also you need to look for a mounting position for an electric starter, if that’s there then all you need are the parts. Internet search, ebay and Amazon are good sources but there are also dedicated Metcury/Mariner parts websites which are also very good sources. You will need the motor part number and serial number, found somewhere on the motor to find the correct fit of the starter motor. Starters are very universal and there are only a few different models so it should be easy to find. I also have a video of me adding a charging coil and rectifier to the same motor, check it out Good luck ! Thanks for watching!

My motor didn't have a starter motor so I had to install one. There was no relay so I needed one in the battery box. If your starter has the relay (solenoid) already on it , you could just add the push button switch somewhere on the motor cowel or handle somewhere. Tap the power off the cable coming in from the battery box but install a fuse in line close to that connection, a big battery can supply huge power and melt down and burn up wires and your motor in seconds! Good Luck! Thanks for watching!

You will need to make sure your outboard has a ring gear and mounts for a starter motor. Of course you will need to find the correct starter motor and ring gear if it’s not already in the motor . All of the electronics are in the external battery-control box. It’s just a relay and a push button. Good luck! Thanks for watching!

See the pinned post on the video, all the parts are there. Thanks for watching

Yes! I try to respond to every question!

I made the electric start conversion before I started this channel, so unfortunately I didn’t start filming when I built the remote battery box and did the starter motor and the ring gear installation on the flywheel. There’s plenty of videos how to pull a flywheel on an outboard so that would be rather redundant. I think I mention the wire gauges and circuit explanation as well as I could after the fact... hope you got some useful info anyways. Thanks for watching!

if it has mounting points for the starter? gear on the flywheel? year? I have no idea, but good luck!

I wish I had documented everything I bought but I just don’t have a link to the part or where bought it, but there are several big mercury part suppliers on line I’ve used so I assume it was one of them. I’ll search my Amazon and ebay history and see if I can find it… sorry

see the post again, I pinned it to the comments

I’ve been looking at eBay, Amazon and PayPal but I can’t find the ring gear purchase. I believe I got it from a Mercury parts dealer. Search there, I’m sure you’ll find it and a diagram showing the exact bolts too. Good luck!

@@bobsbarnworkshop thanks bob

@@billgregory9560 i THINK THIS IS THE CORRECT PART BUT LOOK UP YOUR SERIAL NUMBER ON THE MERCURY MARINE WEBSITE AND LOOK AT THE PARTS DIAGRAM TO CHECK. www.ebay.com/itm/174691241006?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=174691241006&targetid=1068323853270&device=c&mktype=pla&googleloc=9005452&poi=&campaignid=11758057844&mkgroupid=115806620084&rlsatarget=pla-1068323853270&abcId=9300462&merchantid=6296724&gclid=CjwKCAjwgZuDBhBTEiwAXNofRNlsWhjopD0Lpg6xjZlahdXHv2mZ6OYKuC0UKZPmzbiwtdtA4eTVORoCX6YQAvD_BwE

the ring gear part number is: 43-99301, I just searched and found several sources including Amazon. It attaches to the flywheel with 4 metric bolts, M5X13 Funny coincidence is that I just came across the scrap paper I had the part numbers written on

To add the ring gear you’ll have to pull the flywheel with a puller. It may be possible if you pry under the edge and rap on the center bolt (leave the nut on loose to prevent damaging the threads of the shaft) but I used a puller, they’re cheap insurance! The ring gear bolts to the bottom of the flywheel with six small metric bolts, sorry I don’t remember the size of the bolts or the ring gear part number but if I think of it when I’m on my big pc, I’ll check for purchases, maybe I’ll get lucky and find it on ebay or Amazon.

Here's the ring gear I think... #99301 but go to the official Mercury Marine website with the serial number of you motor and look up the parts diagrams to find it, then search for that part number, this is the part number I found on ebay: www.ebay.com/itm/174691241006?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=174691241006&targetid=1068323853270&device=c&mktype=pla&googleloc=9005452&poi=&campaignid=11758057844&mkgroupid=115806620084&rlsatarget=pla-1068323853270&abcId=9300462&merchantid=6296724&gclid=CjwKCAjwgZuDBhBTEiwAXNofRNlsWhjopD0Lpg6xjZlahdXHv2mZ6OYKuC0UKZPmzbiwtdtA4eTVORoCX6YQAvD_BwE

see this post again, all info is pinned in the comments.

Seeing everything except the starter motor is external, I see no reason why not! You’ll need to check for or buy a ring gear ( or a used flywheel with one) and check if there’s mounting holes for the starter. Good luck, ket me know how it works out!

Tegrof not back when I did this upgrade, but about a month ago I uploaded a video where I do add a charging coil and rectifier to this motor

From a website called powerwerx.com/anderson-sb-connectors-sb50-50amp

@@bobsbarnworkshop Thank you BOB , I am getting all my Parts to Build Mine thanks man . working on a 1981 Johnson 25 HP . Putting a starter on it

Johnny Lemoine I think maybe 10 gauge wire would be large enough,? But better too big than too small. Let me know how your project turns out! Good luck!

I have a 1967 evenruge 20 h would love for some one to put a electrical starter on mine

Sharman Price first check for two things, if there are gear teeth on the flywheel and if there’s a mounting place for the starter motor. If it’s got both of those, the rest is easy!

I don't remember the exact place I bought the flywheel gear, but I had to pull the flywheel (I have a puller) and screw on the ring gear... I think it took 6 or 8 small metric bolts. so I reused the flywheel. I think I looked up my engine model on the parts list on a website and then searched for the part number on line. good luck!

Gdawon maybe you can find a compatible motor to salvage a flywheel with a ring gear on it?

Maybe the right part www.ebay.com/itm/174691241006?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=174691241006&targetid=1068323853270&device=c&mktype=pla&googleloc=9005452&poi=&campaignid=11758057844&mkgroupid=115806620084&rlsatarget=pla-1068323853270&abcId=9300462&merchantid=6296724&gclid=CjwKCAjwgZuDBhBTEiwAXNofRNlsWhjopD0Lpg6xjZlahdXHv2mZ6OYKuC0UKZPmzbiwtdtA4eTVORoCX6YQAvD_BwE

@@bobsbarnworkshop thanks mate, not sure? Mercury part for a Yamaha outboard?

Part number of the ring gear: 43-99301 available several places including Amazon

A battery through a relay and a pushbutton, pretty simple!

Yeah, I had to install the starter on the engine, pull the flywheel to install the ring gear, and build the battery box control unit. Sorry I didn’t film that, just wanted to get it done. I hope the description and schematic provided some useful tips, it’s not that complex but I’ve worked with circuits most of my life! If you need any more help let me know and I’ll do my best to provide any info I can! Thanks for watching!

I’m actually trying to locate parts to do the same kind of conversion on my lake neighbor’s 20hp yamaha outboard next summer!

Did you watch the video and explanation of the circuit? Seems pretty clear to me, but I was in electronics for 35 years… sometimes things that seem obvious to me may not be to others! feel free to ask questions and I’ll do my best to give you a clear answer. The engine parts I bought are listed in my pinned comment. Thanks for watching!