seve321 wrote on 04/06/18 at 14:16:40:Its a larger sized paper filter with 1/4in fuel lines. but I replaced it with a new filter and same thing. Also, the petcock outlet is smaller than a 1/4in so it's hard to go any larger than what I have. I'll try with no filter and see what happens.
The problem with the 1/4 inline filters is the hole in the nipples are too small. The plastic housing is thick, so the actual hole in the end of the filter is very small.....and air bubbles get stuck in them and cause an air embolism, and it won't allow the fuel to flow down to the carb.
And......when you reduce the diameter, the change in flow area decreases dramatically as show below:
Stock fuel line is 8mm, and the area is 0.0778 square inches.
Most hardware and auto supply stores don't carry 8mm - so we buy 5/16" hose which has an area of 0.0766", which is a flow area of 98% of the stock fuel line.
When you buy the Chinese copy or other petcocks with 1/4" fuel line, the flow area is now 0.0491 square inches - which provides 63% of the stock fuel line area.
I measured the inlet hole in a 1/4" plastic fuel filter, and I found the hole size to be 5/32", which has an area of 0.0191 square inches - and provides only 24.6% of the original flow area.
So....how well would you perform if I cut your food supply down to 24.6%?