When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Don't know what kind of fuel line your using, but you might check for a soft spot. I had a similar problem and it was a soft spot in the fuel line that would colapse as more fuel was pulled though and open when the engine returned to low rpms.