Mechanical fuel pump, need some help
 

To start I have 454 Mags, year 1991, mechanical fuel pump. Replaced fuel filters and inline fuel filters. Started on port side and the thing would not fire, forever, tore it apart fuel at inline filter but not fuel filter. Went on to the other engine to give it a rest. same thing on that one. But tore apart the filters inline seemed to have more fuel in it but not much more and no fuel in the fuel filter, so I filled the that filter up, dumped some fuel in the carb, stumbled, but it fired and ran fine.

Back to the other engine, put fuel into the fuel filter. Sprayed out the carb with carb cleaner, put more fuel into the carb, fires runs then quits, did that a few time. Took the fuel intake line off of the carb cranked to see if fuel would come out and none. So that led me to the fuel pump. Took it off and took it apart it didn't look to bad, except the return port from the carb seemed kind of clogged. Went into to town nobody had one but Napa ordered it, carter brand.

So I went home and figured Id spray out the pump cleaned the clog from the return, then wen back to put back in. Well the push rod is all the way down, and I cant with my fingers push it up enough, to get the arm in from the pump, am I doing something wrong here?

Is my diagnosis wrong on the fuel pump, I cant believe so, as no fuel was getting to the carb even after starting a dozen times and pumping the throttle probably close to 100 times. I was going to put that fuel pump back in after I cleaned the clog at the return, but I don't think that would keep it from running. But now that I have it out if probably will just wait till the new one comes in as I don't want to do double work. Question is how do I get that push rod to move. Keep in mind I have twins, so I am working at it without seeing anything. I did put pliers in there to see if I could move it, and rolls and moves side to side a little, but I cant get it to go up. I cranked it a few times to see if I could get the cam to move.

A pair of long needle nose pliers can grab the rod or pull the pipe plug out push it back and grease it so it stays put.
What return line from the carb are you talking about?

There is a clear tube that comes off the carb and back to the fuel pump. Im guessing that's just over flow, or maybe a vacuum line?

Might have to pull the plug as I really couldn't get the pliers in there good enough. Tried to get that plug out but was in there good and going to have to work at it from another angle.

That line is just hooked to vaccum so if pump has issues fuel goes into motor vs into bilge. USCG requires.

If pump is not priming and you think it's good check pickup in tank might be plugged.

Is there gas in the tank? Got stranded for a few hours two weeks ago because my buddy's fuel gauge was wrong.

Ill check that, as well. if the other engine ran, then I don't know. theres only one way to check the tank in the fountain there a hatch un the seat to the tank, but Ill check that. Thanks

between a 1/4 and half. Im sure there is fuel. But I guess Ill check. Ran the other engine for 5mins without an issue.

another thing to check is alot of boat mfgrs used drainback check valves these are uaually at fuel tank fitting,sometimes they can stick shut and cause a mechanical pump not pull fuel.

Anti siphon valves stuck closed, probably full of mung. Usually they look just like a hose barb at the fuel tank outlet. Pull the hose off, unscrew the antisiphon valve.

There is a very week spring in there. It checks the flow TOWARD the fuel lines, pump and carb. The purpose is if there is a slight leak, fuel will not siphon out of the tank and fill the bilge.

The pressure difference betwen that spring and the fuel pump's suction action overcomes the spring and lets fuel flow freely.

The ball get stuck and no fuel goes anywhere. Don;t bother trying to clean it, just buy a new one if it's stuck.