gas supply restriction

[deanmay]

I picked up an '84 Aspy this spring with less than 20k miles on it in non-running condition. It had sat in a barn for the last 8 years. I got it running well after cleaning carbs and replacing the fuel pump and filter. I also pulled a fair amount of debris from the tank but there may still be some in there.

The bike sputters under hard acceleration above 4k RPM. I suspect inadequate fuel delivery.

I've replaced the fuel filter twice since putting 6k miles on it this summer. I still don't feel good about the fuel flow from the tank. When I blow backwards through fuel line into tank (cap off) there is considerable restriction. I'm concerned the pick up tube may be clogged with debris and/or pickup screen if there is one. My current plan is to try to pull the fuel gage sending unit hoping it will allow me to see what is going on in there.

Does anyone have any tips on proceeding?

 

[zman]

Sounds like a good idea, run the tank as low as you can or just siphon it out, could also be the pickup tube is partially clogged, mine sat over 20 years and was plugged solid..I ran a cable on a drill through the tube to clear it....gotta go slow and careful if you need to do it, getting a cable stuck in your pickup tube would be tough.
Also careful of the pickup tube screen, I had to be careful not to destroy it with a spinning cable.