im having issues with the pickup in the fuel tank their is very little fuel flowing through it. i took the fuel line going to the tank off and tried blowing in it and could not than i tried to suck fuel out of it and still nothing. is their a check valve of any other obstruction that would cause a restriction. the boat is a 1984 formula 223 with a new mpi 5.7 330hp
thanks justin

the fitting in the tank that the hose is on is an anti siphon valve. it is a little check valve with a ball and spring in it.

could i replace the fitting with a strait through one or would it cause other problems??

depends, the coast guard requires that fuel cannot siphon from the tank if there was a leak down low. because the biggest anti siphon valve is 3/8" (I think) most performance boats use a ball valve that can be closed by hand. that is only allowed if you can close the valve without opening the engine cover. if the pickup is under the floor where you can put a removable cover over it then you can use a ball valve. or if you dont care what the coast guard thinks you can just put a regualar fitting in it but be warned that if there was ever a fire your insurance company may come back and deny the claim as there was no way to shut off the fuel.

Great information thank you
Today I picked up both fittings a straight through and a anti siphon. I replaced the old one with the straight fitting and took the boat out for a test run and it seemed to run without a problem so tomorrow I'll change out the straight fitting with the new anti siphon and test run it again. Thanks Justin