Logo
FULL SITE MENU

1999 Mercury 15HP 2-Stroke Electric Start Conversion

M

Mitch Higgins

New member
Just bought my first outboard engine, a '99 Merc 2S 15hp. It'll be going on a 12' inflatable Zodiac, hopefully it'll have enough power to scoot me and another friend or two along at a fast pace.

I was wondering if someone could shed light on what the electric start kit and charging kit actually do to the engine. The shop I bought it from said they'll install both before shipping the engine to me. Does it add an alternator or does it alter the magneto so that the excess electricity can be siphoned off to the charging kit? I'm thinking it alters the magneto because the electric start kit comes with (what I think is) a replacement section of magneto stator. But then how could the stator be incomplete without the kit and still work to power the engine? How many amps of 12V current does the charging kit supply? Can I still run the motor without a battery and use the manual pull cord?
 
You do NOT need a charging system. (I started my 70 hp triple THIRTY times in a row on a lawn mower battery). Just throw a charger on the battery now and then and you'll be fine.

You can NOT run the motor IF it has a charging system without a battery attached--those electrons gotta go somewhere!

I doubt that gutless 4 stroke will push a 12 footer with two people in it very quickly, but... Been wrong before...

Jeff
 
fastjeff said:
You do NOT need a charging system. (I started my 70 hp triple THIRTY times in a row on a lawn mower battery). Just throw a charger on the battery now and then and you'll be fine.

You can NOT run the motor IF it has a charging system without a battery attached--those electrons gotta go somewhere!

I doubt that gutless 4 stroke will push a 12 footer with two people in it very quickly, but... Been wrong before...

Jeff
Click to expand...

It's a 2-stroke engine.

It's a little too late to go back on installing the charging system, already paid to have it put on. Doesn't matter either way, I'll just buy a small PWC battery and box.

What I am trying to figure out though is how to mount up a simple 0-7000RPM tachometer without having to drill into anything. I've seen Faria's universal outboard tachs as well as Mercury's own tach (part 79-895283A05). I was thinking something like a cup with a roll cage mount or suction cup mount, though I've no idea what would fit or where to find one.
 
The Johnson / Evinrude 2 strokes can be run without the battery.-------Rubber cover must be inplace on the + battery lead.-----So ask your dealer about running without the battery !!
 
Thanks guys for the answers. I'm glad I found out ahead of time not to run it without a battery, it would've been a disaster otherwise.

What size gas tank should I be running for a half day or even whole day out on the water? Any advice on Moeller vs Attwood tanks/lines? Do I need something like the "fuel demand valve" that attwood sells? I don't want to start scrambling for a fuel dock on a 12' inflatable, though I would has a spare quart of TC-W3 on hand anyways :)
 
Last edited:
The charging system is pretty rudimentary. It's just a couple of coils that go under the flywheel that (output) to a rectifier that converts the voltage to "unregulated" DC.

You get a max of about 6 amps if running at full throttle, at lower rpms you barely get a trickle.

The output voltage, likewise varies between about 13'ish volts up to about 16.5 volts. Because of that you need a marine or tractor battery with the heavier plates etc that doesn't mind taking in un-regulated power.

As has been suggested, you could do without the charging component and simply recharge your battery with a trickle charger or low output charger at dockside.

They used to have an option to swap out the rectifier with a "lighting" regulator - didn't feed a battery but you could use it to power your nav lights without having a battery on board.

If you think you may want the charge feature at some future time OR to have the option there for future re-sale without actually hooking it up, the charge stator can be hooked up to isolation strip on the engine block (which effectively sends all the power generated to ground - kinda/sorta) and you don't install the rectifier - so the "guts" are there waiting for "future use".

I have the charge stator with lighting regulator on my rope start 1991 15/2S. At idle it get a dim glow from the nav lights. At half throttle or better they "light up" (if that gives you an indication of how much juice it puts out).

If you almost completely discharged a dual purpose group 27 battery you would probably have to run at full throttle for 15 hours or so to "fill er back up" - so functional to keep a charged battery "topped up", but not much else.

My 15 horse running about 2/3's throttle burns about a gallon an hour (making maybe 13-15 mph - 14' aluminum - total weight of maybe 800'ish pounds including passengers).

With a 6 gallon tank and a 3 gallon spare I can run all day at "cruise speed" under most conditions. The last 1/3 of the throttle causes the gas consumption to go up by about 50%. So unless I have to outrun weather, I don't open her right up.
 
Last edited:
I just received my motor, looks cosmetically to be in great shape. Though there are a couple of things that need to be changed out or possibly fixed. I'm no mechanic though so if anyone here is inclined to take a quick look I'll post pictures I snapped of it.

All photos of engine: http://imgur.com/kB189gq,qzYDhEy,lIc...Qaf5sB,4VpnCkn


The switch on the electric start is disintegrating. Each time I depress it, material flakes off. I'm not sure if I can just replace the button cover or if i have to replace more of the overall electric start assembly. Any part numbers are appreciated, I couldn't find one for it:
http://i.imgur.com/p7GODoA.jpg

There is also a component on the engine (don't know what it is) that has frayed ends on the wire. Should I have this repaired or is it a non-issue?
http://i.imgur.com/UEX5iz2.jpg

At any rate, let me know what you guys think of the motor. It was supposedly entirely rebuilt after some kids ran it "dry" (presumably I guess the mech meant of oil) while it was still on a Mercury Water Mouse. As of now, I am 90% sure it's going on a Zodiac Cadet 350 once the temperatures warm back up in a month or two.
 
I believe the component you're wondering about is an interlock switch...
prevents the electric starter from operating, if the engine is in gear.
 
Yes the starter switch can be replaced can get it on this website. The wires on the neutral safety switch as long as it's working just cover the bare wires with liquid electrical tape. To find parts go on this website to the homepage click on mercury enter your serial# everything you need.
 
Back
Top