125 Force Motor Cuts after starting and won't start again

[Yams]

Brand new to the forum with a recent craigslist purchase. The motor starts really easily the first time and sounds great. I'll turn around and focus on something else, and when I turn back the motor has stopped (30 sec maybe?). Then, when I go to start again it'll either not start, or start for a split second and turn back off. I'm thinking the fuel mixture might be too rich, flooding the engine becuase:
It starts really, really easily after sitting
The sparkplugs were black when I pulled them (but sparking)
When I put the motor up, I can see some gas pool in the black covers in front of the carb
Can't think of another reason why it would start easily and then not start again/cut out

Thoughts? Is there anyway to test this other than changing the ratio? I assume I need to adjust the ratio screw. I've read around and it seems like factory default is 1 and 1/8 turn, but I'm a little confused. 1 1/8 from where, just putting the screw in? From all the way tightened (basically I guess I'm asking which way I should turn the screw to raise the air:fuel ratio)? All my engine experience thus far is diesel (and simple gas stuff like fuel filters) so I'm a little new to a carb.

Thanks!

 

[kbh121956]

You turn the screw in clockwise until it stops. Do not use force, just until it stops. Then back out the screw anti-clockwise to set the mixture. You do this on each carb. The "gas pool" in the bottom of the carb cover is usually sucked back into the motor. You many want to check and see if the hose isn't plugged up at the very bottom. Take the time and remove this cover, remember that it has a hose connected on the bottom and give it a good cleaning. It's also makes it easy to adjust the carbs while this is off. I am not a pro but, I have adjusted my carbs many times. Others on this site will give you answers.

 

[interalian]

Idle mixture screws are set by turning until they gently bottom (count as you turn in to see where they WERE set), then out 1 to 1-1/2 turns. When running and warm, turn all screws in about 1/8 turn at a time then wait 10 seconds or so and see if the motor likes the new setting. Usually you'd turn them in until idle stops being stable, then out 1/8 turn.

 

[pnwboat]

Do you use the choke to start the motor?

 

[Yams]

Great sounds good! I'll try and adjusting the fuel ratio this weekend and see if that helps. I do use the choke to start the motor at first, but then once it won't start I try both. The cover I'm taking about where the gas pools is the black covers that go in front of the air intake - no hoses attached to them. When the motor is up, they aren't vertical so gas pours out of the carb(I assume) and into the black cover.

 

[kbh121956]

Yams, Can you post a photo of the "black cover?"

 

[jerryjerry05]

The 125 carb covers don't have hoses attached.
Look up a parts diagram..
​The 85/90 does.
Do a compression test.
​Low comp on #3 can affect the fuel flow.

​The squeezie, does it get firm?

What's the rpm's at idle? 1100 in the driveway.
The screws on the carb are air/fuel mix for running at idle.
​The idle is adjusted through the towershaft.

​To set the air screw: gently in till it just bottoms out.
Then out 1 1/2 turn out.
There is an equalizer hose between the carbs.
​You need to pinch this off.
Then motor running in the water.
Preferably in gear.
​Turn the top air screw in 1/8th a turn until the motor kicks,buck, stalls.
Then out 1/2 turn.
​You need to wait 10 seconds between the turns to burn the fuel at the old setting.
Repeat on the bottom carb.
Then do it again on both carbs.

But before you do any adjustments. Clean the carbs and make sure the floats are set right.

 

[Yams]

It seems like maybe the best idea is to just clean the carbs instead of trying to adjust fuel ratio. The engine did sit for 2 years so I could see some stuff having built up in there. I'm mechanically inclined, but have never rebuilt a carb. Any good tutorials other than this (http://forums.iboats.com/forum/engi...tions-faq/250235-carb-cleaning-instructions)? It seems like you basically take everything off, soak or spray it in carb cleaner, and then reassemble everything. Would I need to buy a rebuild kit to replace seal/gaskets or anything else?

 

[jerryjerry05]

Take it apart and see how dirty before buying anything?
Sometime it's a piece of dirt so small you cant see it?
Very easy job.
Do it over a cloth so if anything drops it doesn' bounce and get lost(been there).

 

[Yams]

I'll take it apart tomorrow and post some pictures. So the seals and gaskets are reusable as long as the carb isn't too dirty?

 

[jerryjerry05]

There is only 1 gasket.
the bowl gasket.
Just be careful when removing.
I spray it with WD-40 and let it set so the cork can absorb some oil.
​That way it might not rip when removing the bowl.

​IF?? the carbs really bad??? then you might need a rebuild kit.
​It comes with the welch plugs for the passages in the top of the carb.

Some carb soaks ruin the rubber and plastic pieces found in some carbs.
So if you soak? Make sure it's only metal in the soak.

 

[Stingrayaxe]

My 1987 had a similar problem. It was a stuck carb float on the top carb. Gas leaked out and pooled in the black plastic intake cover. A rebuild did the trick.

I would also confirm that your gas tank vent is not plugged. Spiders love those things. Good Luck.

 

[Yams]

I took the carb off today and I don't think that's the issue. I don't know much about carbs (I've never opened one before), but it looked really clean and functional. I blew into the fuel hose when the carbs were right side up and I could hear air going through. Then when I flipped then upside down the air no longer would pass. I've posted some photos, but it all looks very clean and correct to me. I know the carbs are getting fuel, as when I pump the ball enough, some fuel starts leaking out the side of a small port (maybe that's not supposed to happen?). I'll check on the air vent for the fuel tank, but I think its good (can also take the cap off). The fuel mixtures were at 1.5 for both. I've turned them to 1 for now. The spark plugs are black though, so it seems like too much fuel. I'm thinking I'll take the boat to the launch tomorrow and try starting and revving in neutral a bunch. Maybe after sitting for 2 years it just really needs to be worked through. Any ideas for troubleshooting if this doesn't work?

http://bigyams.imgur.com/all/

 

[jerryjerry05]

If your squeezin the ball and the fuel comes out the side of the carb??
Then the floats sticking and probably needs a cleaning.

​The black plugs? not really a problem.
Running at idle can cause this.

​Clean the carbs, I use Dawn and compressed air.
​There are tiny passages that clog and affect the running.

​Check the fuel pump diaphragm.