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Air bound fuel system 94 Mercruiser 5.7L Mag (not electric)

T

Tiger Chet

New member
<div>We have an issue with our boats fuel system. After putting the boat in the water for the 1st time this season, it ran just fine as I motored out the channel. With the channel cleared I trimmed it down and throttled up, the boat began to rumble loosing RPMs. It acted as if something was wrapped around the prop. It would not throttle up without stalling. The distance from the launch to home was just under 2miles. Idle RPM also began to drop&nbsp;off 1100 to 800 as I kept going. On the lift raised I inspected the outdrive and it was fine. Research showed me it was the fuel pump.&nbsp;I also noted a slight rise with my oil level about a pint, typical with GM pumps. I installed the new pump with some difficulty with the push rod. Now the pump has drawn fuel into the filter but has stopped just under full. Prior to the 1st start attempt I removed the filter, drained it inspecting for water. No water was in the system. With my spare filter installed "empty", system was dry all the way to the carb. This morning I blew air from the filter housing down into the tank. At first it seemed slightly plugged but now is clear. Should I try to prime the pump?<br><br><br>Tiger Chet&nbsp;<br></div>
 
considering the anti-syphon valve prevents you from blowing air INTO the tank, check for a ruptured fuel feed hose if your sucking air
 
Thank you for your response. I did blow a small amount of low pressure air into the tank prior to my first posting. I had no obstruction with doing so. Inspection of the main fill, vent and supply line to the filter housing, at the tank were secure, no leaks. The tank is to full open and inspect inside. I did prime the pump just enough to fire the engine. Operating the boat that day it began running better and smoother, About 2500RPMs. If I still have air in the system it maybe working its way out. I would like to post a new thread however I forgot where I found the way in. I see that the BB code is on but DUR.... is there an easy way for a simpleton like me to find it?
Thanks
 
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