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Interesting Problem with Gas Tank

3478 Views 27 Replies 11 Participants Last post by  Blindstitch
My goal was to finally get my bike on the road to find problems and dial things in before paint and some other detail work. I spent most of the day checking fasteners, bleeding brakes, checking connections, etc. in preparation for the big event.

Sadly, I couldn't get it to start. No matter what I did, I couldn't get fuel to the carbs. This isn't the original tank, so I haven't used it (or the petcock) before. I pulled the fuel line and confirmed that gas wasn't getting through the petcock. Off came the tank and petcock (no ride today).

Once I got the petcock off, I was amazed to see that NO FUEL came out of the tank! I cleaned the tank and sealed it with POR-15 about a year ago. Thinking that the tank was plugged, I gently stuck a screwdriver up the fuel outlet. Nothing - no resistance to pressure, no fuel, nada.

I am completely mystified by what the problem could be. The only thing that I can think of, which I can't confirm, is that the POR-15 created some kind of bubble (it would have to be a large one) that sealed off the area around the fuel outlet. For that to happen, there would have had to be a low pressure situation within the tank when the POR-15 was setting up. Not sure how that could have happened.

Any thoughts or suggestions?

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I didn't have much fuel in it, but enough for something to come out. I can't recall if the fuel strainer was in the tank or not when I got it. I don't think so, but that would be pretty hard to confirm. You're right, though, if it was in there, and in place, that's most likely the problem. That thing would have withstood 1,000 bb's shaken and shaken and shaken, but that could do it.

Would you suggest pushing a bit harder with a screwdriver? The first screwdriver I used went all the way to the handle, so I got a MUCH longer one. It hit something, which appeared to be to be the side of the tank.
I had the cap off and the tank tipped so that the fuel outlet was at the lowest point - no fuel. However, the cap was on the tank when I had it on the bike...

You bring up a good point, though, and another potential problem. I only have one gas cap and had in on the tank when dispersing the POR-15. Uh oh...

The cap was on the tank when I had it on the bike...
I just checked, and I can blow through the vent in the gas cap. It seems a bit constricted, but I don't have anything to compare it to. I stuck a welding tip cleaner in the hole and poked around a bit. No improvement.

I'll play with it more in a few days. (I don't smell like gas now and Mrs. likes that). My schedule probably won't allow to mess with it until at least Wednesday (but probably next weekend). I'll keep you posted, but let me know if you come up with any other ideas/suggestions.

Thanks for everyone's help!

I tried the light but couldn't get a good angle to see to the back. However, I think I'll see if I can see light from the filler through the outlet...

No confirmation either way on the strainer.
Guys -

Thanks for all of the help. Gsting - glad I saved you the trouble and glad you showed me how to fix it. I've got an in-line filter installed already. I may or may not add the screen back in - my thinking is that I can see trash in the inline filter, and it's easier to replace than the screen.

Just got home and confirmed that the screen is still in the tank. I'll take it out this weekend and take that first ride on Saturday!

Thanks, guys!
OK. I was able to remove the screen and get the bike back together and running, but now both of the carbs are leaking fuel (quite a lot of it) from the float bowl drains. This was not a problem when I first started the bike (with an auxiliary test tank) several weeks ago. The float bowl drain screws are new.

I'm stuck all over again. Any ideas, oh wise one's?

FYI - I rebuilt the carbs to the best of my ability with Larry's book and a Randak kit.
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