How to completely drain fuel from tank?

Started by KyleMCMXC, April 24, 2015, 01:55:29 PM

Previous topic - Next topic

KyleMCMXC

So I'm really close to getting my bike back together and trying to start it with my rebuilt starter.  The last obstacle I've come across is getting all of the fuel out of the tank.  I've drained/siphoned almost all of it out but the last bit down in the lowest parts of the tank is evading me.  Due to the rim around the inside of the cap you can't even flip it over and dump it out.  That fuel sat in there all winter without any additive in it and it's coming out with a rusty appearance.  What I can see of the tank (very little of course) shows no signs of rust but I know from reading on here that the lowest corners are where the rust usually is.

1. Would this color result from gas just getting old in the tank or do I definitely have a rusty tank?

2. Any tips on how to get the last of that shitty fuel out?

3. Is there any chance that I'll be able to get by if I just fill the tank all the way (thereby diluting the old fuel) and install a fuel filter or should coating the tank really be something I absolutely have to do before running it?

Other than dying to ride, I'll be moving in about a month and I'd rather be able to ride the bike to my new place instead of having to find someone with a trailer or a truck.
1982 XZ550 Black - In progress...

turbosteve84

I got pretty good results by removing the petcock. And yes, there's rust in the tank. You can flush it out with a gallon or two of fresh gas (what you do with the flushed gas is another problem). But from reading this forum I've learned that all the tanks eventually rust at those low points, so you're most likely just buying time.  --Steve
Steve
saddlebums.tumblr.com

Rikugun

Like Steve said, removing the petcock should allow you to get all the fuel out. I'd hold and tilt the tank over a clean drain pan and check the remaining fuel that comes out for actual rust particles. In other words, determine what you are seeing is rust or just old discolored gas. Pulling the petcock will also allow you to investigate and identify what foreign matter (if any) has built up around it's screen material.

If it's rust you're better off dealing with it now and postponing your desire to ride. A fuel filter will not stop the fine particles. Assuming your carbs are meticulously clean (and they should be), they may not be for long if you chance using a rusty tank.
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

Jirik

For draining I use longer pipe, tube and big syringe. It's necessary remove fuel tank from bike, rinse tank with fresh fuel and pour the fuel to the left side lowest point (under the filler neck). With fuel you will suck potential mess from fuel tank. After that I let it dry on sun, or dry it with rag and use vacuum cleaner and compressed air to suck all powder from dry tank.