siphon old gas out of tank?

[sailors hornpipe]

i bought a 1992 180 nitro fs with 150 hp johnston evinrude- we took it out once ( my boat mechanic buddie and i) just to check for needed maintenence - it had trouble starting and he had to use starting fluid and run it on high neutral for awhile - it took about 4 trys to get it started and once we ran it in the lake for awhile and shut it off - it would restart right away with no hesitation - my bud says i need to drain the old gas out which i estimate to be 10 gallons - i have thought on how i would do this and saw a 10 dollar siphoning pump with tubing at walmart and planned to buy and siphon out old gas - but then i read another thread here that made me think twice- the thread was asking how to clean out an old gas tank - apparently the thread starter has debris in his gas tank and wants to clean it out- the replys he got were to use a shop vac or siphon and to be sure to ground himself to the tank - then someone said (dont use a shop vac! ) as it is electric and could cause a spark- it was also mentioned that a n empty gas tank is full of fumes and very explosive- mind you the temp here in my part of texas is going to be at or above a 100 degrees for the next week at least- so first how do you ground yourself to the tank? second am i going to create a bomb in my driveway by emptying the tank? third what is a fuel sending unit and am i going to damage anything by inserting a siphoning tube into the tank? fourth where do i dispose of the gas? fifth if i do nothing / what is runnig the old gas through the engine going to hurt? i know the boat was sitting at the boat dealer since at least nov of 2009 when it was traded in (supposing the salesman is telling the truth) and dont know when it ran last before that - so we are guessing the gas is at least a year old . what do yall think

 

[Dick Sorensen]

Re: siphon old gas out of tank?

I also got a 1984 boat that had been sitting for over 10 years. Because I really didn't want to have fuel problems....(varnish....debris...) and I was replacing the flooring entirely....I just ordered a new tank from the original manufacturer....$400. plus freight from Florida to Ohio....But, for my piece of mind a very small investment...because we don't have a long boating season I didn't want to lose one day due to fuel problems....(fuel and electrical seem to be the biggest reasons for marine engines not running) ..... also I checked with three local radiator shops and all of them stated they would "boil" the fuel tank but no guarantees and one guy even came clean and told me that after 30 years in the business boiling would not guarantee a clean tank....I know I'm not helping you solve your problem but I wanted to share a different approach....why not get as much out with an old fashion manual pump....fill it up with high octane gas and try the boat out....maybe if you keep changing the fuel filter and nothing breaks loose your home free! If not grab a sazall and cut that puppy out!

 

[Lrider]

Re: siphon old gas out of tank?

Don't know how your system operates, but on my outboard I have a fuel line from the tank to the motor (DOH!) I disconnected it from the filter extended the gas line to a 5 gallon gas can (7 of them) took my air hose put les than 1 psi in the tank filler to just start the siphon. (using more pressure to speed the flow is not clever the fuel tank is not designed to hold any pressure and you could damage it) worked like a charm

Now what do I do with a half tank of gas (35 gallons of bad gas) I live in California land of EPA

 

[Bifflefan]

Re: siphon old gas out of tank?

i bought a 1992 180 nitro fs with 150 hp johnston evinrude- we took it out once ( my boat mechanic buddie and i) just to check for needed maintenence - it had trouble starting and he had to use starting fluid and run it on high neutral for awhile - it took about 4 trys to get it started and once we ran it in the lake for awhile and shut it off - it would restart right away with no hesitation - my bud says i need to drain the old gas out which i estimate to be 10 gallons - i have thought on how i would do this and saw a 10 dollar siphoning pump with tubing at walmart and planned to buy and siphon out old gas - but then i read another thread here that made me think twice- the thread was asking how to clean out an old gas tank - apparently the thread starter has debris in his gas tank and wants to clean it out- the replys he got were to use a shop vac or siphon and to be sure to ground himself to the tank - then someone said (dont use a shop vac! ) as it is electric and could cause a spark- it was also mentioned that a n empty gas tank is full of fumes and very explosive- mind you the temp here in my part of texas is going to be at or above a 100 degrees for the next week at least- so first how do you ground yourself to the tank? second am i going to create a bomb in my driveway by emptying the tank? third what is a fuel sending unit and am i going to damage anything by inserting a siphoning tube into the tank? fourth where do i dispose of the gas? fifth if i do nothing / what is runnig the old gas through the engine going to hurt? i know the boat was sitting at the boat dealer since at least nov of 2009 when it was traded in (supposing the salesman is telling the truth) and dont know when it ran last before that - so we are guessing the gas is at least a year old . what do yall think

All grounding is, is making a connection. If you think its going to be a huge issue, hook a wire to the tank and hold on to it. then there are no sparks.
DONT USE A SHOP VAC!!! what are you crazy????
Id use a cheap pump that hooks to a drill and just pump it out in to a can and then get rid of it.
I took 28 gals out of my tank in about 10 mins with one. Ran a hose from the tank through the bilge drain, (motor was out) and then hooked the pump to it and a short hose to the tank a few cranks and it was gravity feeding the rest of the way.
All done.

 

[FunInDuhSun]

Re: siphon old gas out of tank?

First, DO NOT use a shop vac to pull out the gas!!!!!!
You can usually smell bad gas. If there's any doubt, get rid of it.
IMO the easiest way to get the gas out is to put the boat on a trailer (or cradle if no trailer is available) and manually siphon the gas out thru the sending unit hole. If that's not an option, then maybe use a manual fuel pump.
The sending unit itself is simply a float with a potentiometer that measures resistance. They typically bolt to the tank with 4-6 bolts.
Get as much out as possible, then I agree with ****- put in some high octane and run it thru. If the boat doesn't have a fuel/water separator, now would be a great time to add one!

 

[KermieB]

Re: siphon old gas out of tank?

If your gas tank is aluminum, you won't have a spark problem. It only sparks when using a grinder on it.

....oh, and borrow your neighbor's lawn mower to get rid of the old gas. Better yet, put it in your mother-in-law's car.

 

[saumon]

Re: siphon old gas out of tank?

we took it out once ( my boat mechanic buddie and i) just to check for needed maintenence - it had trouble starting and he had to use starting fluid and run it on high neutral for awhile -

Boat mechanic, starting fluid and high neutral, humm something tell me that your buddy isn't really a boat mechanic but more of a car mechanic that say ?yeah, i'll help you with this boat?, right?

You should never use starting fluid in a 2-stroke (no lube) and not rev it past 2000rpm in neutral for an extended period of time.

To drain the gas: take the hose coming from the tank, disconnect the fitting at the engine, remove the fitting from the hose, place the end of the hose lower than the tank, pump the primer bulb until gas is coming and voila! it will drain by itself (you won't have to pump once it start flowing).