1995 Force 15 hp smoking..a lot! Help!

duckhams

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Dec 7, 2015
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Bought this motor a few weeks ago for $400. The old man told me it need new needle and gaskets. Did that, as well as new fuel pump gaskets. Not sure if the needle is sitting right, as it'll run for 5 min in the bucket then cut off. I'm assuming it's flooding, but not sure. Also, when I pump gas in from the tank, it'll start running out the front of the carb.

Any advice on the smoking and fuel coming out of the carb?
Any advice will help as i'm clueless.

Attached links are videos of it smoking.

Also- I'm so confused as to who made my motor. It says "force by mercury marine" but also says "gamefisher" on the back of the housing. So confused by that too.
 

duckhams

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tommarvin yeah its 50:1 mix. I believe I mixed it correctly, but could be a little rich. I'm just not sure if it would make it smoke it as much as it was. or maybe it would i'm not sure. I'll add some gas to it and lean it up and try again
 
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flyingscott

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It is a force motor built after mercury bought them in the early 90s branded as and sold by sears as a gamefisher. The gas coming out of the carb would lead me to float level being to high. Also did the guy you bought it from use fogging oil at all that will smoke like that. Could also be a bad float but doubtful 50-1 is correct.
 
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duckhams

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flyingscott not that i know of. If he did add fogging oil, is the only was to make better, is to just run the motor and burn it all out?
I'll lower the float a little and see what that does. I hope the float is okay
 
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flyingscott

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Yes let it run until it clears up also lower the float as that can also make it smoke. The primer should get hard when you pump it,
 

Frank Acampora

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Whenever you run a small engine in a barrel, especially a small barrel like that one, you will see smoke. The burned oil and exhaust have no where to go except up and out of the barrel so you see a lot and think it is not normal. Once it is in the boat, the exhaust will be buried in the water and the boat will be running away from it instaed of concentrating it in a small volume.

As for the carb, it sure sounds like the needle or seat is worn OR the float is incorrectly set or hanging up.
 

duckhams

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Frank Acampora yeah that makes sense with it being such a confined space. hopefully that's just the problem.

flyingscott Okay, tomorrow I'll lower the float a bit and see what it does. I never get full pressure in the bulb primer or the hand pump from the fuel tank.

Thanks guys for your advice thus far!
 

jerryjerry05

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The running and shutting off sounds like there is a problem with fuel delivery???
It's gonna smoke until​ the unburned gas/oil is all gone.
The fuel connectors could be leaking and it's sucking air?
If you changed the needle?? Did it match the old one in size?
Dismantle the carb and make sure the floats level when the carb is upside down.
Hook a piece of hose to the fuel inlet.
Blow into the hose when it's upside down.
No air should be coming through.
 

duckhams

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jerryjerry05 i ran it again today with no changes except leaning the gas down with about 1/2 gallon of gas added and it ran pretty good for 5+ min but i had to cut it off after that due to smoking the neighborhood out! I got the carb kit for the motor and installed the needle it had. but the needle i took out had a rubber tip, while the replacement has metal. what's the difference and could this be a factor?

If it's sucking air, will that cause it to smoke?

the smoke reduced tremendously when i'd lower the engine to a slow idle
 

foodfisher

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I had a similar smoke problem. Cleaning the fuel recirculation system cleared it up.
 

jerryjerry05

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The rubber tip will have to go back in.
The metal tip is used wit​h a seat that has an o-ring in the bottom.
The way it is is metal to metal and the seal it makes isn't very good.

It needs to be at 50-1 or you can do damage.
Too much oil can be as bad as not enough oil.

The more you run at a slower speed(in a barrel or on a hose) the more it's gonna smoke.

It needs to be ran in the water and ran at almost full speed.

The air screw should be set while warm.

Like foodfisher said, cleaning the recirc system might help.
 

duckhams

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jerryjerry05 thank you for the advice! i'm going to put the other needle back in and see what that does. When you say "air screw" do you mean the screw that sets the idle?

and where is the recirculation system? is that behind where i put new fuel pump gaskets?

thanks again
 

tommarvin

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I'm guessing the " air screw" is the air fuel mixture screw on the carb, not the screw that adjusts the idle RPM, I don't know where the recirc system is, if were supposed to be cleaning it ,I sure would like to know, I'm guessing its the cylinder drain, you guessed the transfer port ?
 

jerryjerry05

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It's called a cover assy. or cylinder drain.
It's on the stbd. side and has screens in there.
It recirculates the unburned fuel.
It can get clogged.

It's located in the front of where the pump is mounted.
Get a parts diagram. ​boats dot net has a couple of good diagrams
 

oldboat1

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need a big repurposed trash barrel, with the leg dipped deep (about half way up). Keep the hose running, and keep the speed at idle or high idle. Let it run for a half hour or so with clean gas and oil. Open the idle needle about 1 1/2 turns open (counterclockwise) initially. Start the motor and warm it up, then see if you can set it leaner. rpms will increase as you lean (throttle it down to lower rpms -- should idle smoothly at 650-700 in gear.) When dialed in and run for a while, should be getting less smoke. Don't run it wide open, or whip adjusting screws back and forth like in those YouTubes.
 

fishrdan

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The old man told me it need new needle and gaskets. Did that, as well as new fuel pump gaskets.


Fuel pump gaskets? Was that the fuel pump rebuilt kit, including the diaphragm? Just checking as a 30 year old rubber fuel pump diaphragm could be ruptured and causing raw fuel to leak into the crank case, causing the motor to smoke like you're seeing. If the fuel bulb is not pumping up hard, you may want to disconnect the carb's fuel line and block it off, then pump the bulb again to see if it gets hard. If you can still push fuel with the bulb, if could be leaking inside the fuel pump, past the diaphragm.

These motors are notorious for loosing a BIM coil pack, which will drop a cylinder and still idle relatively smooth, just down on RPM a bit at idle. Pull a plug wire to see if it dies, then the same thing for the other cylinder. It should still run with 1 cylinder firing. If it's only running on 1 cylinder, that could explain the smoking also. Those BIM coils are NLA, but there is a company (Chicago Magneto or something of the sort) that can make replacements, $75/100 each. Or, there is a complete ignition system upgrade for around $200, that's what I did and haven't had a lick of problems since...

As for the motor dying after 5 minutes, Check over all the fuel lines and especially the quick disconnect, to see if they are leaking, leaking when priming from the priming bulb. If fuel leaks out, air can leak in, and cause the outboard to suck air and run out of fuel. I've had to replace the quick disconnect on mine a couple of times due this.
 
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