Topic: emptying a tank of fuel...suggestions?

[gregwaits]

I am trying to get all the old gasoline (varnish at this stage) out of my gas tank before proceeding to flush it out and fill with fresh fuel.

I removed the petcock from the tank and let the tank sit over a large bucket overnight, and barely a trickle has emerged! What can I do to speed this up? I hesitate to turn it upside down and try letting it run out of the filler hole.

Oh, I don't have a siphon, and I would prefer not ending up with a mouth full of this #$%*. 

Any suggestions are greatly appreciated!

If it matters, the tank is from a '78 CB750K8.

Thanks

[dustyc]

Seafoam will soften that varnish, so you could put some of that in the tank and let it sit with the petcock closed.  Maybe also add some fresh sacrificial gas to make sure you're getting the stuff that's up higher on the sides.  Better to do it now rather than have it end up in your carbs.

If that doesn't speed it up, work on it in a tray with gloves and remove the petcock.  It's probably crudded up with old gas.

[754]

If its over a bucket, unbolt the petcock.

Or just turn it upside down..

[ofreen]

I removed the petcock from the tank and let the tank sit over a large bucket overnight, and barely a trickle has emerged! What can I do to speed this up? I hesitate to turn it upside down and try letting it run out of the filler hole.

You took the petcock out and you still only get a trickle through the petcock opening?  You must have some impressive crud in that tank.  I'd just turn it over and dump it into the bucket, then look in there with a light to see what's up.

An easy way to get about every last drop out a tank is to stuff a rag down the filler hole, leaving some sticking out.  Shake the tank around so the rag absorbs the gas then pull the rag out.

[Steve F]

Turn it upside down.  That way you'll get all the crap out including any water hiding in the lower seams.  I flushed mine out with mineral spirits afterward (it has a higher flash point and is safer than gas).  Then do the de-varnishing thing.

[casnelso]

If you want to remove gas from a tank without ending up with a mouthful of it, you could always buy a siphon pump from an auto parts store or Wal-Mart.  Mine came in a kit of emergency car supplies.  It looks like the primer bulb you would find attached to an outboard boat motor fuel tank with clear plastic hose attached to each end.  The hose is of small diameter so it takes a while to move a large amount of fuel through it, but it works well and doesn't involve gasoline entering one's mouth. 

[neil young]

get a piece of hose.any diameter,fill it with gas or water since you wont be reusing the old gas .then press your thumb over one end of the hose.no liquid will spill out from the open end this way.drop the open end in the tank ,dont take your thumb off the end of  the hose yet .put an empty container lower than the tank.with thumb still on hose lower it into said container,release thumb and a siphon will happen on its own.make sure the hose is full of liquid or it wont happen.
hope this helps

[paulages]

i believe the '78K has the standpipe/screen style petcock filter, which is easy to accidentally leave in. sorry if this is obvious, but you might double check that it's not still in there. the hole should be completely unobstructed--if it's still in, you'll see some plastic inside the hole. i've seen a filter clogged enough to stop flow even with the petcock removed.