Have a fuel delivery problem that is driving me crazy. I have a marine power 5.7 gas carbureted engine. I recently had an issue where my Holley 4150 was getting flooded out by too much fuel coming from the carter 7 psi electric fuel pump after coming off plane. Filled the fuel bowls until over flow. I figured it was a broken float or needle valve issue so I took the Holley apart for a rebuild and found lots of corrosion so I decided to get a new carb. QFT M-650. When I installed the new carb I also put in a fuel pressure gauge between fuel pump and inlet to the carb. Installed all and ran great. Pressure gauge ran 6.5 psi. All good for about 3 hours of running on plane and back to idle several times.
Then later in the day I noticed the pressure went down to 4 psi from the 6.5 psi. Fuel level in the bowls did not change much from being in the center of the sight windows and boat still ran ok. I was thinking bad anti siphon valve of clogged filter and would check that out back home. But then after running on plane for about 5 miles I came back to idle the boat started to stall bad and noticed the fuel pressure reading 12 psi and not a steady ready. Very erratic movement of the needle in the gauge. float chambers were full of gas, so full that gas was coming out of the j tubes. Same exact problem as I had with the previous carb installed.
What the heck can make a fuel pump rated for 7 psi max run to 12 psi and flood out my carb?
I have all new 3/8" fuel lines and all hoses are tight.
New 10 micron fuel filter/water seperator
brand new carburetor
Then later in the day I noticed the pressure went down to 4 psi from the 6.5 psi. Fuel level in the bowls did not change much from being in the center of the sight windows and boat still ran ok. I was thinking bad anti siphon valve of clogged filter and would check that out back home. But then after running on plane for about 5 miles I came back to idle the boat started to stall bad and noticed the fuel pressure reading 12 psi and not a steady ready. Very erratic movement of the needle in the gauge. float chambers were full of gas, so full that gas was coming out of the j tubes. Same exact problem as I had with the previous carb installed.
What the heck can make a fuel pump rated for 7 psi max run to 12 psi and flood out my carb?
I have all new 3/8" fuel lines and all hoses are tight.
New 10 micron fuel filter/water seperator
brand new carburetor