Topic: Draining the tank

[eigenvector]

What is the best position for draining the tank that requires minimal fuss?

I'm prepping the tank for a relining job and it seems like on the 550's the tank is so full of crevices that there's no real good position that allows the tank to be emptied without resorting to shaking, and rolling it around.

I'm taking it on short 5 mile rides to get the gas down as far as it can go.

Is simply leaving it on the bike with the bike on the centerstand the best position for draining?

[Retro Rocket]

Take it off and turn it upside down..

[70CB750]

Not sure about 550, but 750 tank lid hole has a flange and it is impossible to drain all fuel out.

[Retro Rocket]

I try and get most of the fuel out by any means possible, then put in a clean rag and soak whats left up, sit it the sun for a bit and its all dry, even swish some methylated spirits {alcohol} around in there and it helps it all evaporate..

[calj737]

Upside down works well on some later 550 tanks, but the earlier ones need to be worked on the left side to drain completely. Get the fuel level down, pitch the tank to the left rear, and pull the petcock. Then when the flow quits, slowly flatten the tank to get the remainder out.

Flush well with soapy water, follow with Acetone. Then line it (etch is a good recommendation after acetone).

[eigenvector]

Alright, I was hoping there was a better way - but flip it on it's side, then flatten it out seems to be the trick then.

I suppose the trace that's left in there isn't a huge deal.

[calj737]

It is a big deal actually. You must flush with soapy water to fully rid the tank of fuel before lining it. And the tank interior must be fully dry. I don't whether you plan to use an etching product, but a good internal dousing with Acetone will dehydrate the water (and fully tumble the tank in all orientations) and itself. Let stand, etch, liner install.

Some people use compressed air too, but, unless you have a dessicator on your compressor, the air you blow in itself will contain moisture  I use chemicals to dehydrate or add a heat gun (carefully with the paint in mind).

[70CB750]

I spray the inside of empty tank with gun oil.  Light enough to wash in first gas tank full.

[mystic_1]

I wouldn't be putting any oil into a tank that i was draining in order to apply tank sealer.  That's ruin any chance of the liner sticking.

There is no easy shortcut here, unless you want the liner to fail.

Calj737 has given some good advice here.  Drain the tank as much as possible.  Fill with soapy water, swish it around good, drain.  Add some acetone, swish it around, drain.  Allow to dry in the sun. 

Throw a big handful of short wood screws or deck screws into the tank, close the cap, and shake the tank around to abrade the interior surfaces with the screws.  This will remove any flaky rust, and give the surface a little bit of "tooth" for the liner to grab on to.  Rinse again with water and then again with acetone. 

Then, inspect the inside of the tank using a flashlight and if necessary repeat the wood screw treatment.

Last thing you want is to have a failing liner being pulled into your carbs.

mystic_1

[przjohn]

After the tank is cleaned and thoroughly rinsed with water I use a hair dryer taped to the cap and set on low. With the petcock removed it blows out that hole. It's important to get all the water out from the seams that the hair dryer gets out.

[70CB750]

Ah, liners. I consider them waste of time and effort.

The best liner out there is to ride the bike and keep the tank full.

[eigenvector]

I'm listening to you Cal, you've posted many a times about this before, which I'll happily leverage beforehand.

I'm really only doing this because my previous attempt, using Kreem, failed miserably.  I don't blame Kreem specifically - at the time I did it I simply didn't understand the importance of certain things when prepping.  Draining the gas was what I was asking about because it does requires some finesse - you can't just up-end the tank and watch it pour out, nor can you simply remove the petcock. 

As for the old lining - that's covered amply in other posts as well.  It's 99% gone, but it should be 100% gone.