TOPIC: 1974 9.9 15 hp low profile.A Little service info

Hi folks! I got a pair of motors for cheap,, a 9.9 and a 15hp. Both same generation, the 15 is known to be a 1974. So, Im trying to get the 15 going,, bad coils, got them ordered. Heres the confusion. Does this motor have a stator? Its pull start only, and as far as I can tell, it only has a charge coil. According to the limited info in the manual, the electric start has a stator, but the pull start motor has only a charge coil?

Not sure about this because the manual sucks, and both motors were slightly incomplete. Im having to complete 1 of them first, then if it goes well, I will un seize the other and see if it will run.

First pic is whats under the fly wheel, its got the charge coil on it.

Second pic is a 19" trout I caught on my glasspar last week, some kinda hybrid the ranger lady said. almost 4 pounds. Caught on vega reservoir, mid day, bouncing a worm off the bottom of the deep end. Only thing i caught all day.

Yes, that is a charge coil under the flywheel, but that's for the ignition system only. The electric start versions came with a "stator" which really was just another set of coil windings bolted to the stator plate, whose only purpose was supply current for the charging system.

I suppose if you wanted to power up, you could install the "stator" and a rectifier, wire it up and feed lights or charge a trolling motor battery.

Not cheap though, about $130 at marineengine.com:

www.marineengine.com/newparts/part_details.php?pnum=OMC0582097

Nice fish, good eatin' I bet!

Thanks! I might see about rigging up a charging system. The motor will be used on a 12 foot 1958 alumacraft, which also gets a minkota trolling motor, so theoretically, I could use a smaller battery for the minkota, and recharge it every now and then from the gas motor.

It would sure be nice to be able to have a light weight set up in that boat.

I dont know how good the trout tasted! I had no ice, and my lunch cooler wasnt big enough,, so I found some folks in a little rubber raft, and gave it to them. That fish was like JAWS. It nibbled several times, then after hooked, ran straight for under the boat. It tried to hide, or perhaps escape through tangling the line in the motors in back. At one point it was squarely in between the big evinrude, and the little merc, and I though it was a goner.

Pure luck got it free from the motors and into the boat, where it immediately came un hooked.

Seems like a great idea to have a charging circuit. Im hoping the alumacraft will be kind of a hot rod, so lights would be great.

A little bit of help for other folks who might be fighting one of these motors. This one had been gone through by somebody else. The carb and ignition were all messed up.

I went through the ignition first because it was getting gas. Had new points and condensor, but not set, coils were dead. At first I just set points and replaced coils, but still no spark.

So, then the points came off, and got cleaned with 400 grit and clean paper. One set was conducting good at 3 ohms, which is reference for my meter, so basically perfect. The other would fluctuate between 9 and 12. Believe it or not, that was enough to make it not fire. After cleaning the set of points, and getting them down to 3 or 4 which again 3 is reference, I put them back in, and set them again. After this, it was getting a good blue spark. Seriously, that little difference is the only change noted when testing things.

Then it started, but was flooding out real bad. So off comes the carb. Float level was waaaaaaaayyyyy off, like a quarter inch? Anyway, the adjustment was made by bending the float arm. By doing this the needle would never seal, so the bowl was filling up, and it was flooding out.

Hmmm, im not sure about that.



Low speed needle was set at 3/4 turn out from seated. Its a very simple carb. 2 gaskets, the float needle assembly, 2 brass caps, 1 low speed needle, thats it. I didnt take the seal caps off though. Probably more under those.

Anyway, the worst part is re attaching the carb. The throttle arm has to be attached to its links, but not screwed in to get the nut on the carb flange. This is a pain. It takes creative use of pliers, magnet and finger tips, but once mastered, can be repeated easily. The worst worst part is trying to screw in the carb link screw with its washer. A very long super skinny flat screw driver helps here, and small fingers would be great! Anyway, it has to be done after the carb nuts are tight.

Once those are conquered, its simple, just the intake and the knob, choke lever,, all of wich are pretty self explanetary.

After getting all buttoned up, I lifted the motor back onto the boat, hooked up fuel and water,, primed the bulb hard,, and 1 pull, no kidding, 1st pull! Started clean, idled up in neutral, idled down even all the way down without cutting out. Actually had to use the kill switch to make it stop.

Still havent run at any speed in gear. Hopefully tomorrow. Going to try and get videos of both the 75 and the 15 at full song. Im hoping it runs out as well as it started and idled.

Pic of the carb nut. I ended up positioning it with a magnet, and spining it with my fingers to start.

With any luck,, fully swapped from merc power to Evinrude. The big 1 runs fantastic!

Its actually a 15hp, I think. Anyway, I should check serial numbers. Got a 9.9 and a 15 both in the deal. Supposedly the 9.9 is the parts motor, froze up. The 15 cowel is rough,, but conveniently the 9.9 cowel is good. Thats what everybody does anyway with these things.

Yup, they can be a bit of a pain to work on until you get used to them, but they are very good-running motors. Quite peppy too.

Still one of the most popular fishing motors ever built, along with the almost-indestructible pre-1980 6hp models.

Well, it was a productive session at the lake today. Now Ive got her starving for gas! Ill need more info regarding the float level setting. Im sure thats what it is. Wouldnt top out, and wouldnt start but for a couple seconds after the initial start and run. Big one worked perfect though.

Might be fuel pump also. When trying to restart on the water there were bubbles in fuel line, and it acted like no gas getting into the carb at all. When priming the bulb real hard it would restart for a few seconds but thats it. Not getting gas one way or the other. Im real glad its getting spark. Nice to put one issue away, and work on the next.


Im going to yank the parts motor carb and see if its been messed with. I dont want to have to pull the carb off the runner any more than 1 more time!

Any info here much appreciated. As far as I can tell, its supposed to be float level with bottom of carb face at approx 1/16" gap as measured at front of the float. Pretty much like in my pic above.


Any differing info or opinions greatly appreciated.

Allright, I think its figured out. I cleand the 15hp carb meticulously. Used air to ensure that all pasages were clear. Set float bowl somewhere between where I pictured above, and flooding.

It ran great! Started easy, ran great for a good 7 minutes or so. Then I killed it, to try a re start, and no go. Obviously, something is plugging up the slow speed circuit. I could re start by adding gas to the intake, then quickly put in gear and advance throttle to run the high speed circuit.

Then, after another couple minutes, it lost rpm at full throttle, then lost more rpm, then started sputtering. I killed it again, and it wouldnt re start no matter what,, except for a few seconds at a time by adding gas to the intake. Wouldnt run at all though after all that.

So, I fired up the big motor and put in for the dock,, only to have the big motor start cutting out! Seriously,, it was a real drag limping in like that.

A day later,, Ive got it figured out. That 18 gallon gas tank is plumb full of rust. The 40 micron fuel filters just let it pass right on through.

Thats what was in the 15 carb.

Im hoping the 75 carbs will somewhat clean them selves out by running good clean gas through them. Or, I may become familiar with speedifour carbs!

Heres another pic of the 15 carb, intake passage that directly feeds the float needle.

These pictures are AFTER I had already cleaned the 15 carb, and ran for just a few minutes at the lake for testing. Completely plugged.

So, the whole boat gets new plastic gas tank(s) and I will try to filter the old gas. Looks like ALOT of micro rust floating around though. Going to have to find some 10 micron filters at least to clean out this old gas.