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Discussion Starter #1
I run a blue holley pump and noticed that it holds 7lbs cruising and on a speed run it has started dropping to around 3lbs and then takes about 15 to 30 seconds to go back up to 7 going bad or is the spring sticking
 

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I think that as long as it's keeping the bowl(s) full of fuel it doing it's job just fine. Are you experiencing symptoms that would lead you to believe that it's leaning out?
 

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Discussion Starter #3
I think that as long as it's keeping the bowl(s) full of fuel it doing it's job just fine. Are you experiencing symptoms that would lead you to believe that it's leaning out?
I have been having to jet the carbs up since i changed the heads and cam over the winter, and i hadnt noticed the fuel pressure drop until yesterday and it concerned me since i have been changing the jetting
 

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My holly set up does about the same, I have to set mine up to like 9 lbs, if the key is on, and the boat's not running, and when I look at the gauge at speed it reads about 1/2 that. I was curious to see what others had to say here also.
 

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I run a blue holley pump and noticed that it holds 7lbs cruising and on a speed run it has started dropping to around 3lbs and then takes about 15 to 30 seconds to go back up to 7 going bad or is the spring sticking
Chris ,

Take the bottom plate off and check to make sure all the 4 phenolic vanes are moving freely. I'll bet you got some water in the fuel and the center steel piece has some surface rust on it causing some off the vanes not follow the housing. If so take it out and clean it up good with some 400 grit sand paper and/or a red scotch brite and it should be fine.

Loren
 

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Chris ,

Take the bottom plate off and check to make sure all the 4 phenolic vanes are moving freely. I'll bet you got some water in the fuel and the center steel piece has some surface rust on it causing some off the vanes not follow the housing. If so take it out and clean it up good with some 400 grit sand paper and/or a red scotch brite and it should be fine.

Loren
good advise:)devil

hey chris, that holley blue is a bit small for that motor. we put a holley mechanical on billy's blown 540 and it holds 4-5psi at wot, and it was 100bucks,and there's no regulator need ( to slow fuel flow;) )
 

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Chris,
Lorens's advice was right on regarding Holley electric pumps. I've had several just lock up over winter storage from moisture turned to rust in the vanes(even when I lived in Calif.!)
I might add, don't fixate so much on the fuel pressure. The VOLUME is way more important. Every motor has a minimun volume required at WOT.
I too got smart years ago and now just run a big Clay Smith 170 GPH mechanical pump. They will handle over 1000 hp. Jocko
 

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There should be NO pressure drop at any load/rpm. For every one pound of pressure drop the float level will drop app. 1/8" in a Holley carb. Pressure drop is an indication the engine is using more fuel than the system can provide. Don't forget: The system consists of tank, vent, fuel pickup, lines, pump, regulator and carb and all parts need to work together for the system to work correctly. If the boat's tank has a top draw p/u make sure the check valve is working properly, I can't say to remove it as it is a CC required item and I would never recommend to do something illegal.;)
 

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