Gas not getting to Carburator 2004 bigfoot mercury 25hp outboard

Fredfloat

Seaman
Joined
May 10, 2015
Messages
68
With the gas tank right at the bottom of the boat I'm wondering if I can siphon it out? Doesn't the can that's receiving the gas have to be lower than the tank? I got 2 cans of Seafoam today and was wondering about putting both in the approx. 4 gallons that's in there and then go trolling with the motor. Not a good idea?
 

Fredfloat

Seaman
Joined
May 10, 2015
Messages
68
OK. I relented and got some of that 98 octane non ethanol gas. With the gas tank being so low and the boat always in the water I couldn't figure out how to get a gas can lower than the tank to siphon so I disconnected the gas line from the motor and just squeezed the bulb 4-500 times till the tank was empty. I mixed in 2 cans of Seafoam with the new gas. It still was hard to start but putting it in nuetral and giving lots of gas got it going. It still sputtered when giving much gas but seemed to be getting better the more I ran it. In the end I could give it full throttle. At times it still hesitates but still I feel like maybe some of the gunk that's been clogging it up may be getting washed out. Thanks for the tips to get me this far.
 

Fredfloat

Seaman
Joined
May 10, 2015
Messages
68
The boat hasn't been used since the last post. Yesterday,it started once and was run a little. After stopping for a while tried starting again but wouldn't catch. One thing it's doing now that it wasn't before is it'll crank but then just stop cranking and make sort of a whine sound.A puff or two of white smoke on cranking too. Try it again...crank for a bit then just stop. Any ideas what that is? I'm going to take a video next time I'm down there. Thanks for any tips.
 
Last edited:

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,048
Old battery ? ------Recharge battery.----Better yet , have it load tested !
 

Fredfloat

Seaman
Joined
May 10, 2015
Messages
68
Plugs getting gas?

Not sure what you mean with this? My mechanical knowledge is very basic but if it's a simple enough procedure or if I see a video showing how to do something I'll give it a shot vs the hassle of getting out of the dock to the shop.
 

Fredfloat

Seaman
Joined
May 10, 2015
Messages
68
Recharged battery (rather than using jumper cables on a smaller battery) and got it started. I chugged along with full throttle only producing about 20% of the normal power. Then after 15 minutes reduced the throttle to 1/3 and it started going faster. I figured I was just trying to run the 98 octane and 2 cans of seafoam through. After an hour I was able to get full power although it would sometimes sputter and I would have to reduce the throttle for a while then eventually it would again go full speed. I'll try it again when the weather allows. Thanks again for the tips.
 

Fredfloat

Seaman
Joined
May 10, 2015
Messages
68
Tried it again a month later. At first it wouldn't start. Then I took off the caps to the spark plugs and sprayed contact cleaner and lightly sanded the threads. I didn't take the plug out. I think I need a special wrench for that. After that it started, no problem. I took it out and it ran steady with hiccuping or faltering but wouldn't get past 1/3 to 1/2 power no matter what I did with the throttle. When I'd reduce the throttle to 1/3 it showed occasional signs or trying harder but didn't respond like last time. I ran it for 3o minutes up and down the lake hope to get the hi octane gas and 2 cans of seafoam to clean the carburetor. Is there a chance that replacing the 2 sparkplugs might do something? Thanks
 

Fredfloat

Seaman
Joined
May 10, 2015
Messages
68
Tried it again a month later. At first it wouldn't start. Then I took off the caps to the spark plugs and sprayed contact cleaner and lightly sanded the threads. I didn't take the plug out. I think I need a special wrench for that. After that it started, no problem. I took it out and it ran steady with hiccuping or faltering but wouldn't get past 1/3 to 1/2 power no matter what I did with the throttle. When I'd reduce the throttle to 1/3 it showed occasional signs or trying harder but didn't respond like last time. I ran it for 3o minutes up and down the lake hope to get the hi octane gas and 2 cans of seafoam to clean the carburetor. Is there a chance that replacing the 2 sparkplugs might do something? Thanks

That should have read...:ran steady without hiccuping or faltering". Is there a way to edit these posts once they've been put on?
 
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