Help me electric start my 1974 Merc 20hp

[DaubsNU1]

Started looking around the interwebs for a starter and parts to make this happen.

 

Serial number is 4055053

 

Suggestions or advice greatly appreciated! 

 

Thanks!  Daubs

[DaubsNU1]

Found on eBay a connection for parts to make this work.

 

They have:  starter, solenoid, battery cable, start switch for my model outboard.

 

They do not have: Lighting (charging) stator, or the voltage rectifier. These would re-charge the starting battery.

 

Would I need the stator and rectifier?

 

Boat has two batteries...battery #1 runs the 12v / 40lb trolling motor.  Battery #2 powers my Garmin Echmap 7sv and occasionally the Garmin Striker 4cv.

 

I would power the outboard starter off of Battery #2.

 

 

[Way2slow]

I think you will find there's a whole lot more to it than just putting a starter on it.  Pull rope motors don't have a charging system, electric start motors do, so they have a different flywheel, the stator, the rectifier and wiring.  I think you are going to find out, it would be cheaper to just find another motor.

[DaubsNU1]

Wise words @Way2slow. Thank you.

 

My old Merc does have a flywheel compatible with a starter. Adding a starter would not stop my ability to start outboard with the pull rope.

 

I realize without a stator and rectifier that the battery will not get a charge.

 

The lakes I fish with this boat are small, less than 500 acres, and many are 5mph limit / no wake. I would use the starter ~2-3 times per day, if that. Battery gets charged after every trip.

 

Parts are going to cost me ~$190 shipped.

 

The boat-motor-trailer cost me $600 back in 2000. With all the decking, electronics, and additions...I might have ~$3k in the boat total. It has been a fund building project to see how much capability I can get from this 60+ year old boat, at minimum of cost. Adding electric start is more of a "can I make this work" vs. "I need this to work."

 

If I were fishing bigger water, or longer trips...that's when I fish with my brother in his Lund Alaskan 1800.

 

[airshot]

Check around for small repair shops that work on boat motors, many have old stock laying around from junk motors.  Any area with lots of bodies of water will have small shops around. 

[Way2slow]

I looked at putting a starter on my 85MY, 25hp merc and decided it wasn't worth it.  I think on mine, the flywheel, even without the charging system was not compatible, it didn't have the ring gear on it.  The guy I got it from had converted it from tiller to remote control and steering, and still had the tiller, so I took all that off and put the tiller back on. (I bought boat, motor and trailer for $200, just for the motor and trailer and trashed the boat). Putting it on my jon boat, I looked at adding stick steering but figured if I was going to have to get up and go back to start the motor every time, I had just as well stay back there and run it.  Mine starts easy enough with just one short pull of the pull cord (after the initial cold start) that I can do while sitting on the bench seat at the back.

Want to add remote control and steering, I might be willing to get rid of that stuff I took off mine, if I can find it now, that was a lot of years ago.

[Alex from GA]

I had the same problem with the same engine and a friend had a starter and the mounting stuff.  I drilled the lower case and put a button there.  No it doesn't charge the battery but lasts for several days with a group 27 battery that I also use to run the trolling motor.  It was hard for me to pull.  Starter, solenoid, mounting and button switch.  $200 is worth it.

[airshot]

I used to have an old Johnson 30 hp outboard motor that did not have a charging system.  Just a group size 24  six volt battery would last me weeks if not a full month before needing charged, and I used running lights and radio often.  Doesn't take much battery for starting a small engine...

[Way2slow]

Trust me, I'm not blaming him for wanting a starter.  Back in the early 70's I bought a brand new 25 Johnson with a starter and no charging system and never had problem.  If was just the simple matter of putting a starter on my 25 Merc, I would have done it 20 years ago when I bought it but no ring gear was the butt kicker.  Another flywheel for electric start was very difficult to find and, even used was more than I paid for the motor.  Not counting all the other stuff it needed.  It just was not worth the cost.  That's why in my first post I commented he may be getting into more than he bargained for, but if his has the ring gear and the starter will bolt up and work, I would do the same thing.

[DaubsNU1]

Parts are ordered, and on their way. They are even providing a few wiring diagrams.

 

@Alex from GA and @airshot, I did some google searching and found similar situations starting outboards without a charging system. Some talked about experiences in the 1950's and 60's...starting their boats from battery for a few days, even weeks on one charge.  Then getting the battery charged, and repeating.

 

My old Merc takes 4-5 pulls to start in the morning...then starts on first pull the rest of the day. It's not an issue for me now at 55 years old...but some day it might be.

 

I agree with you @Way2slow, if this required a new flywheel + more, would not be worth the hassle.

 

I will post up pictures and maybe a video when I get installed. 

[WRB]

There is also a micro switch needed on the neutral shift lever to allow the electric start motor to engage the flywheel.

You don’t want to start the engine in gear, but can with the pull start.

Tom