Gas not getting to Carburator 2004 bigfoot mercury 25hp outboard

Fredfloat

Seaman
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May 10, 2015
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68
I'm not too knowledgeable about motors. The boat hasn't been used since last Spring. It started up fine recently. There wasn't much gas in the tank. It sputtered some when I took it out. Some days later I squeezed the bulb (like always) and it got firm. It was cranking but not catching. I have had luck in the past with replacing the fuel filter. This time I took it off and replaced it with an extra I had but remembered I had replaced it in the Spring and it didn't look dirty. I unplugged where the gas goes into the motor (after the bulb) and gas squirted out of the motor when I press around the connection. There was gas in the filter. The bulb stays hard after trying to start it. Any places that I could check and maybe do something with before hauling it out of the lake to a repair place? Thanks
 

Fredfloat

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May 10, 2015
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68
Arrow on the bulb pointing to the motor ?

Nothings changed with the bulb. It's been on there for a long time. It used to be that I might be going along fine then the motor would sputter and stop. Then I'd go back and squeeze the bulb and it would get going again. There seems to be gas getting at least to the filter and I just put on a new one. It seems to be something stopping it after.
 

QBhoy

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Mar 10, 2016
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Hi
i was going to suggest the bulb being wrong way too, until I read further.
Certainly a strange on if the bulb the right way, the filter the right way and all else well. I’m not sure there is anything else other than the float being stuck that would stop fuel getting in there. Have you tried opening the drain screw on the carb and pumping the bulb ?
 

Fredfloat

Seaman
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May 10, 2015
Messages
68
Hi
i was going to suggest the bulb being wrong way too, until I read further.
Certainly a strange on if the bulb the right way, the filter the right way and all else well. I’m not sure there is anything else other than the float being stuck that would stop fuel getting in there. Have you tried opening the drain screw on the carb and pumping the bulb ?

Any chance of a pic or link to what the drain screw on carb looks like? I'm that green on motors but will do what I can because its a hassle to get this thing out of the water (ask friends with trucks, air up trailer, drive to expensive dealer etc.)
 

Fredfloat

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May 10, 2015
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I'll take a picture of it the next time I'm down there. Thanks for the comments.
 

QBhoy

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Hi
sorry just catching up. It’s very obvious. Flat headed screw usually on bottom of carb.
 

Fredfloat

Seaman
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May 10, 2015
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I made a little video showing how it sounds when trying to start. Bulb is tight after pumping. I changed the fuel filter last time. Today I looked at it and saw the a\arrow was pointing toward the bulb so I took it off and now the arrow points to the motor parts. Unfortunately it sounded exactly the same. It turns over but won't catch. Here are the pictures. If someone wants to circle where the screw is I should loosen to see if gas is getting through I'd appreciate it. Thanks
this is the video:
https://youtu.be/FqksvJY61pc
 

QBhoy

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This shows my mechanical level. Could you make a screenshot of my picture and show where it is? Thanks

Just under here. There should be a flat head screw there somewhere. Don’t take it right out or you might loose it in the bowels of engine. Just crack it open and see if you can pump fuel through and out the drain, using the fuel primer bulb.
 

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Fredfloat

Seaman
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May 10, 2015
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Just under here. There should be a flat head screw there somewhere. Don’t take it right out or you might loose it in the bowels of engine. Just crack it open and see if you can pump fuel through and out the drain, using the fuel primer bulb.

carb screw which one.jpg Great. Now to double check. The top one or bottom? Thanks!
 

QBhoy

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Yeah. Bottom...unless you are in a zero gravity environment, haha.
 

Fredfloat

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May 10, 2015
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68
Right, I saw on reread you said flat screwdriver. I'll be giving it a look next time I'm at the boat. Thanks.

A friend with pretty much the same boat (and knowing some more about motors than me) came by. I showed him that screw but before loosening I tried to start it. It has a lever to give gas and change forward/backwards. I knew to push the key in to choke. I didn't know, until he did it, how to put it in neutral.That round part at the bottom of the lever. I thought it was just molding covering a bolt! So he had it in neutral and gave it plenty of gas and it started right up! However, once we got going the gas was having a hard time getting through. If I put it at full throttle it would go slow. If I backed it down to half it would go some faster. The motor hasn't been used much at all for the last 18 months. When I tried it for the 1st time in many months it started and I ran it a short ways. I then noticed there was very little gas in the tank. It's a built in plastic tank in the back. Later I took a 5 gal jug of non-ethanol unleaded and put it in. But that was when I couldn't get it to start at all before I knew about the trick of putting it in neutral. He thought it sounded like a gummed up carburetor or maybe bad gas. Normally he puts non-ethanol 98 octane racing gas in his. So now I'm trying to figure out the best way to get the gas (which was also sitting around all summer in a gas can) out of the tank and replace it with better gas. Any tips on the simplest way to get it out? Not much of an expert at siphoning gas. Also thought about putting in additive like Seafoam. Thanks for the advice.
 

Fredfloat

Seaman
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May 10, 2015
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68
Turning over buying a couple of cans of that Seafoam and putting it in the 4-5 gallons that's in there?
 

Fredfloat

Seaman
Joined
May 10, 2015
Messages
68
If the gas is already bad in the tank then you should remove it and start with fresh gas...

Actually it was a new gas can (plastic) and the gas just sat there through the summer unused. I suspect crud is getting into the carb but still trying to get a little use out of the boat before the weather completely changes so I'm trying to see if I can get some of that stuff out before hauling the boat out.
 
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