Gummed up tank clean out

[firstbase]

My dinghy outboard carb seems to be gummed up (again) after being cleaned and rebuilt. Need to get rid of the old gas and make sure 6 gal. tank and lines are clean with new fuel. Whats the best way/thing to put through them to clean them up? Trying to not buy a new tank and fuel lines if possible.

 

[meridian]

If you have run any ethanol gas the fuel lines may be deteriorating on the inside.

 

[firstbase]

No ethanol according to the previous owner who I believe.

 

[OldDan1943]

No ethanol according to the previous owner who I believe.

Do you disconnect the fuel like from the tank and run the hose and carburetor dry?

 

[Irish Rambler]

Its a problem when old fuel is left in and evaporates leaving the gummy deposits. Easy start will clean the carb and BUT ONLY USE SMALL AMOUNTS. Spray it in the air intake and turn the engine over by hand just sufficient to get a little suction to carry the easy start in the chambers. Be extremely careful not to start the engine. Leave it for 15 mins then start the engine. if its a small outboard/chainsaw etc turn it upside down and shake it vigorously, turn it back and try and start it.

 

[what_barnacles]

seafoam will fix it.

 

[firstbase]

Do you disconnect the fuel like from the tank and run the hose and carburetor dry?

No I didn't. bought the boat in March 2017 and got around to checking out the dinghy January of this year. So 9 months of sitting since I owned it and don't know how long it had been since PO used it. Had to have been a while. When I went to start it in January, nothing. Had the carb cleaned and rebuilt but did nothing with the fuel. Dumb now that I think about it after the fact. Asked the mechanic about the fuel and he said "Nah, fuel is ok" so I dropped it. Now after 2 hours of use won't start. As I said above, there is no indication of anything in the fuel or in the onboard filter. Clean as could be.

 

[Mkeller]

I burn unused outboard gas in my cars after 3 months. The idle gets on my 4 barrel carbs will pass anything. The pinhole on an outboard not so much. I learned the hard way not to use last seasons gas whether or not it was stabilized.

 

[Dwk]

If you have run any ethanol gas the fuel lines may be deteriorating on the inside.

I had a similar problem. The fuel lines were deteriorating from the inside, replaced the with ethanol friendly lines.. no more trouble.

 

[FF]

"I burn unused outboard gas in my cars after 3 months."

This is OK ,,,IF you have not added oil for a 2 stroke engine.

The gas dies more rapidly with the oil, so should be car burned after 1 month.

 

[jleonard]

"I burn unused outboard gas in my cars after 3 months."

This is OK ,,,IF you have not added oil for a 2 stroke engine.

The gas dies more rapidly with the oil, so should be car burned after 1 month.

I have been burning the leftover 2 cycle gas in my truck for years. Never a problem.
It's maybe 2 or 3 gallons into a mostly full 30 gallon gas tank.

 

[boathealer]

Seafoam. Add to fuel, every time without fail.

 

[firstbase]

"I burn unused outboard gas in my cars after 3 months."

This is OK ,,,IF you have not added oil for a 2 stroke engine.

The gas dies more rapidly with the oil, so should be car burned after 1 month.

A month? Wow do I have a lawn mower and some yard equipment that is REALLY disappointed in me right now!! Or are you just talking outboards..??

 

[Mkeller]

"I burn unused outboard gas in my cars after 3 months."

This is OK ,,,IF you have not added oil for a 2 stroke engine.

The gas dies more rapidly with the oil, so should be car burned after 1 month.

My late model suburban at 50,000 miles was burning as much oil on its own as my 100:1 premix outboard. Adding up to six gallons to a 33 gallon tank was unnoticeable.

My 71 Buick 455 loves a little more top end lubrication. And those huge carb jets will pass anything short of sludge. If over 3 months old I do run it through a filter to remove water before dumping it in the tank.

 

[mike66]

What type of outboard do you have? My Tohatsu 4 stroke will have problems unless I use a Racor spin on filter, and run the motor dry after every use. I unplug the fuel line to motor connector and plug in a spare connector not connected to anything and let it run dry. Takes about 5 minutes.
Once a year, a carb tear down and soak in cleaner keeps it pretty good. Also have a spare $100 carb that I can rotate in if needed. Price we pay for a clean motor.

 

[cappy208]

Try to find a place that sells ‘non ethanol’ fuel. They’re tough to find. Depending on how much gas you use a summer they sell ‘tru-fuel’ at most small engine stores. Expensive. But no ethanol. Ethanol in gas plays havoc with small engine carbs.

 

[Civilitas]

There’s an app for that!

It is called “RealGas” and you can download it to your smartphone or tablet. It will geolocate non ethanol gas vendors near you and with price data.

 

[BruceK]

My 6hp Tohatsu 2 stroke has no problem burning 1 yo fuel.

 

[firstbase]

Problem solved, water in lines, carb. Both lines and tank were aging but showed no obvious crack or leak so I threw away both and replaced with new as well as non-eth gas from one of the local stations. My best theory is that the tank had a recessed area around the fill cap that opened all the way to one side. I'm sure you know what I am describing, The recess allows water to drain off the tank away from the fill. Well, it would as long as the tank was level or angled down to allow water to flow and not pool in the recess. Our dinghy is angled in the chocks on deck, port side a little higher than starboard. Gas tank turned the wrong way in an angled dinghy made a nice little pool area around the aging fill gasket. This caught the rain water which soaked through into the fuel. We have had the dinghy covered until recently and everything was good. Left it uncovered for a couple of weeks during which it rained. There you go. At least that's my highly developed scientific theory. Oh, and mechanic said there was ethanol debris in the carb as well. Either PO was telling me a story or he got a load of bad gas from someone.

 

[firstbase]

Try to find a place that sells ‘non ethanol’ fuel. They’re tough to find. Depending on how much gas you use a summer they sell ‘tru-fuel’ at most small engine stores. Expensive. But no ethanol. Ethanol in gas plays havoc with small engine carbs.

We have several gas stations on the main drag to the boat ramps that sell rec gas and then some on the water around my area. Not worried about getting it locally but when we cruise it will be a different story.

 

[FF]

I am told the oil needed in a 2 stroke OB kills the octane rating (pre ignition) very rapidly.

The racing OB guys need good high octane for their highly stressed engines.

They mix and use the fuel same day.

No question dumped into most cars or trucks it OB fuel burns just fine.

 

[TowLou]

Mainly I add techron to my 2 cyl gas mix through the summer I am ok if i run non ethanol gas. Ethanol gas I have had very poor results in my lil bassie. Clogged screens and not happy motor when I used straight road gas.