Help with fuel tank

[MulhollandDrive]

Hi Everyone... I recovered my 1977 CB750K and decided to get it started after 30 years. I pulled the tank, removed the fuel cock and emptied out the tank. There is some rust, but still a lot of shiny metal. The rubber gasket on the fuel cock has disintegrated. My question is what to do with the outer tube that is stuck in the tank. The inner tube came out with the fuel cock. If I look inside the tank, I can see a tube sticking up inside the tank. I am waiting on a replacement fuel cock, but I am starting to wonder about a strategy to get the tube out of the tank. My first idea is to find a wood dowel that matches the tube and try to hammer it inside the tank with a rubber mallet on the wooden dowel. Any other thoughts?

The good news is that I was able to get all four plugs off and turn the motor over with the kick starter.

JAL

[vern401]

could try screwing a wood or sheet metal screw into the plastic and try pulling it out that way. the threads will need to be wide enough to grab the plastic tube but not to big as to damage the tank opening.

[Re-run]

I know that in my tank, when you look under the fuel cap door, in the bottom left corner, there is a hole. There is a tube here for gas spills. If you were to fill this tube, it goes to a "clear"(after 30+ years it is probably yellow)tube that drains behind the engine. I am not sure if this is on the earlier tanks.
 
So that may be what this tube is.

[MulhollandDrive]

Hi Vern... Good idea. I had not thought of that. I am hoping that the replacement part will shed some light on the stuck part which I think was the fuel screen.

[MulhollandDrive]

Re-run... So that is what the hole is for! And yes, the drain tube is very yellow.

[MulhollandDrive]

Vern... Just a f/u. I bought a new petcock assembly and it was clear that the base of the fuel screen tube was designed to keep the tube from going fully into the tank. I used a large screw as you suggested and was able to back out the 33 year old screen tube! Success!

Thanks,
JAL

[vern401]

f/u. ? got me lost there. the good thing is you got it out.
Now for the rust problem... you do not want rust in the tank naturaly so My next step would be to get the rust out. you can use CLR to do this somewhat. I did use it on a kawasaki tank once and it did work to a point. That tank is in need of it again so I do not think it got it all out. There is another post on here that shows another way of getting the rust out. That is how I plan on getting the rust out of the kawasaki tank this time. Once I get it out I will use baking soda to neutralise the scid and brake cleaner to dry the tank along with an air compressor. then I will put the petcock and fuel guage sending unti back in and fill it with used motor oil. This I will let sit for a day or so. drain it and will with gas.
The link the the post is below.
http://honda-cb750-s.456789.n3.nabble.com/Tank-rust-removal-electrolysis-method-td969475.html#a969475

[MulhollandDrive]

Vern.. What do you think of using WD40 instead of old oil?

[vern401]

WD-40 is water based. it works well on de rusting bolts etc but I would not use it for this application.
If you do not use old oil then you would want to have enough new gas aviable to fill the tank.
The trick is to the the water out and then fill it full so that it does not "flash rust".
I have heard of a few different things to use but once you have the tank dry you
want to eather coat it, treat it, or fill with fuel.