Fuel problems

[ixd704]

Hi,

 

I'm new so hope I'm doing this right. Anyway, I just finished taking the back end of my 85 apart to get the gas tank out as I have a fuel leak. I drained the tank (lots of rust bits came out) and filled it with water to see if I could find the leak. So far it does not appear to be leaking.

 

The only reason I went after the tank was that I lose 1/2 tank of fuel in about two days with the petcock closed. Anyone know where else it could be leaking? The sending unit does not appear to be leaking and the petcock is brand new (changed it last fall as I thought it was leaking). Anyone else run into this? Could it be a seam that opens when the temp changes? Although I put cold water in and now the sun has heated it up pretty good.

 

Anyone try the POR-15 products to clean and seal their tanks? Anyone know where a good used dealer is that I could buy one from?

 

Thanks,

Ian

Edited May 18, 2009 by ixd704
Adding bike year

[gscbertrand]

You could try some Rad shops to see who will line it for you I've tried home shop liners and can never quite get the same results that my rad shop does. They also check for leacks and weld them if any are found. P.S. put some sea foam into your gas tank when you fill up next time try looking for it in car part retailers. Out here we have a company called Piston Ring where I buy mine.

Edited May 18, 2009 by gscbertrand

[Condor]

With that kind of loss you have to be smelling gas fumes or seeing some evidence of leakage somewhere. If you're not you may have other problems...

[ixd704]

Thanks for the reply. I've heard of Seafoam before and plan on getting some (NAPA sell it here). I'll drop my tank off at the rad shop tomorrow and get them to pressure test it, clean it and seal it.

 

While I have everything apart, think I'll change all the hoses and fuel filter (sure it must be full of crap). Would anyone know if the preformed hoses are still available? If not, I'm guessing I can use any good quality braded fuel line.

 

Thanks,

Ian

[ixd704]

Hi Condor,

 

Oh ya, I smell fuel. So bad that it gets from the garage into the house sometimes (kids hate it). If the level is below 1/2 a tank smell is very slight and it seems to hold the remaining fuel.

 

Ian

[GeorgeS]

Are you sure its not a hose, valve to filter, filter to pump, and pump to top of Carbs.

 

Also, have you considered, that you might have a Float Valve stuck open ??? Each carb has an Overflow line, each runs aft, and down to the rear shock.

 

Fuel , might be siphoning thru a carb, and out the overflow line.

[StarQ]

Check your oil, make sure the fuel isn't leaking into the crank case.

 

Do you see any kind of puddle on the ground around the bike?

[ixd704]

Took the tank to a rad shop and had it pressure tested. Leaks like a sieve with numerous pinholes once pressure is applied to it. I guess the head pressure from a full tank was enough to get it to leak down to half a tank. When it warmed in the sun, pressure would rise and force the fuel out. Once down to under half tank the head pressure was not great enough for it to leak out very fast.

 

Shop going to cut out rusted section and seal it. Thought of getting a used tank, but then again, it will also be 20 years old.

 

Might make a mold of it and make a fibre glass one over the winter.

 

Thanks for the replies.

 

Ian

[barend]

Dragonrider has one listed for sale (bid) I think with proceeds going to St. Jude! Tank appears to be in good condition with minimal (as in next to no) rust showing in the neck

 

Just so you know

[84xj1100]

You may want ot check these folks out for parts

 

 

http://www.flatoutmotorcycles.com/fiche_select.asp

[jasonm.]

for minor pinhole leaks. A good coat of acid core solder on the holes followed by POR15 sealer can save a tank. I know. Done it to 2 other bikes.

[MiCarl]

 

Might make a mold of it and make a fibre glass one over the winter.

 

 

The marine industry ditched fiberglass tanks because gasohol was ruining them.

 

Don't know about there, but it looks likely that all U.S. gasoline will have 15% ethanol soon.