Quickie rusty fuel tank fix to "get rideable"

Hi Guys,
Let me first say that this is an extremely helpful, friendly and informative site. I joined about two years ago when I acquired a '97 VFR 750 but haven't posted anything here since the bike has been 100% trouble free. Anyway, a couple of weeks ago I picked up an '86 non-running VF500 F in rather ratty condition, but it is basically all there and its credible PO said it last ran about 1.5 years ago. It needs lots of attention before I can get it running but one of the things I wanted to do early on is to get the tank functional. I have read numerous posts on doing a real tank restoration, but wanted to just get most of the rust out to where the tank would be usable in the short run. I'm not saying what I've done is desirable but it is quick.
The process involves getting the rust out with one of the jointed, small bar magnets we mechanics use to retrieve nuts and bolts dropped in inacessable places. I would add about half a gallon of fresh gas, agitate the tank and them stand the tank on end petcock end down, slightly tilted so the gas was all in the corner of the tank below and to the right of the petcock. I would then repeatedly insert the magnet through the petcock hole and move it around in the lowest corner to pick up the rust particles.
I would then drain the gas out the petcock hole, add fresh gas and repeat the process. To get the last bit of gas out of the tank corner I used a 3/8" id plastic hose with a squeeze bulb like used to prime outboard motors and pumped out the few ounces that won't slosh out.
The whole process took about an hour and the last couple of flushes picked up virtually no rust.
Again this is not recommended, but I'm hoping it might be useful to someone in similar circumstances, or as a first step in a more complete fix. I need to confess that I'm the kind of person who believes, "You can tell it is high quality workmanship because there are no wrinkles in the duct tape."

 

I pour the gas out into a suitable container, but not the gas can. Then a small bottle of clr and swish it around, let stand for 20mins then add very, very hot water and swish it again. Note to others put gas cap back on, save the burning sensation of when the water tries to come out. I let that sit another 20 mins then swish and rinse and repeat until the water comes out clean. Add fresh gas with some ethanol gas anti-freeze in it and swish it around again then pour in with the rust filled gas.

At this point I have always just used tank sealer to seal the tank, but it will be fine to run without in the short term as long as it doesnt leak. 20$ for tank sealer is worth it imho.

 

Put a clear inline fuel filter on it when you're done. Harbor Freight carries these, as does O'Reilly's Auto Parts, and loads of other places. It's cheap insurance.

 

Very cheap insurance. Keeps all sorts of crud out of carbs, sometimes it also keeps the crap some places try to call gas out too

 

Probably have some rust in carbs from PO. Do a compression test on that 500 before spending too much time or money just to see what potential you're working with.

 

I use bearings in the tank and agitate the tank multiple times with fresh solvent each time. I then add dish soap and hot water and again agitate the tank a few times changing the soapy water each time. Then mutiple hot water rinses. I then blow the tank with compressed air. Make sure its completely dry. Might take a day. I'm with Zen, use a tank sealer. I've done this with not only bike tanks but tractors, and auto tanks. You could use nuts in place of the bearings if you had to.

 

Good way to find out! For some reason using a hydraulic in a gas engine never seemed to work in my mind, if using diesel just make sure you rinse with a good bit of naptha, it will remove the diesel coating.