fuel problem ???

1995 24' Outlaw----friends boat----454 w/we think 330 hp---carb engine------If the boat sits 2 days or longer ---carb is out of gas and we have to pour a lil in carb to start up-once started, idle's pretty good----but raise her to 1000-1200---rpm--she wants to stall and we have to keep pumping the throttle---runs great at 1500 rpm and above-----under power over 2000 rpm runs great but she seems to surge just a little ???? It looks like it has an after market electric fuel pump!!!! Stop at a Pub--1 or 2 hours later, she starts right up!!!! Only after a few days she is dry !!!
BAD CARB (edlebrock) BAD FUEL PUMP????
Merry Christmas to all and hopefully I'll have my boat on the water after the 1st of the year !!!!
Mike-----Tampa Bay !!!

When you say carb is out of gas, the bowls are completely dry? Or you notice when you pump the throttle there is no spray and your not sure if the bowls are dry?

We assume the bowls are dry because when we pump the throtle-no spray----but after priming her and running her and stopping for awhile--when you pump the throttle she will spray and start right up----

i would get carb rebuilt first, gas evaporating is leaving gunk. that is why need to raise speed, idle circuit has build up of varnish. then check engine temp, is it running hot and creating lot of heatsoak when shutdown boiling off gas in carb, could try spacer under carb if so. run bilge blower before shutdown, do you idle to cooldown or open run to dock with soon shutdown. just some thoughts.

Is there a missing check valve or something letting fuel get drawn/drained back out while setting?

hmnnn---the engine does not run hot----He does not idle to cool down-just a shut off-----but she will start right up and will start right up even after sitting a few hours at some pub---aftre towing a hour home, she starts right up for a flushout-----but if she sits 2-3 days--bone dry---have to pour a lil gas down her and then she fires up-----??????
A missing check valve letting the fuel leak back ??? I dunno---I would not know where to check for one, unless it's on his after market fuel pump---we will look !!!
Thanks so far-----Mike

See if this makes sense to what you are experiencing...

Dry carb, excessive cranking, what's the problem? - ChevyTalk --The Social Network for Chevy Fans

Ratickle--thanks--I was told the fuel pump is not up to par----pouring gas down the carb starts the engine--the engine pulls fuel up the line w/ some help of the fuel pump--at idle there is enough pressure but up on plane she purges cause the pump is not putting out staedy and enough fuel pressure--sitting at a pub she begins to slowly drain but still has enough gas to fire her up---over night she drains back past the worn out fuel pump and hence we have to re-prime her again---Pep Boys has the same elec pump and a carb kit soooo today will be work on the boat day!!!! I thank all you guys input and hope everyone enjoyed a Merry Christmas !!!!
Mike---Tampa Bay

Let us know the results.....

OK---We bought a carb rebuild kit from Pep-Boys----Yes.. they sell a Marine carb kit----same jets--ect-----and us.. two DYI clowns cleaned her with Power tune--new jets--new washers/gaskets----ran the boat and she run great------------after a week of sitting again ,,,,,,,she needed gas poured down the carb to prime her and get her started again---SOooooo like the Merc Tech told me---FUEL PUMP--!!!!!!!! (Same guy building my engine) SOooo my buddy has ordered a new fuel pump!!!!
Mike---Tampa Bay

Is your fuel pump located in such a way that it holds fuel to it. If the supply hose to the pump leads down hill from the pump there may be nothing to hold fuel at the pump. A loop or something to hold fuel in the pump may help. Electric pumps do not draw fuel they push it.

Thanks--YES his electric fuel pump is mounted in the back, on the head, the height of the valve cover !!! AND the fuel hose from the tank comes from tank (floor height) up hill !!!! We will look at this set-up this week-end---------------Thanks again ---Mike---Tampa Bay!!!

Quote:

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Originally Posted by MOBILEMERCMAN

Electric pumps do not draw fuel they push it.

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It will work better closer to the tank.

Hmmmn should we put her down close to the tank--run the hose in a circle to hold gas...and try that????? He just bought this boat, so we don't know if the previous owner had this problem or not?? He had to have the same problem!!! It has a brand new engine in her !!! Should we ditch the electric pump and put in a manuel (on the block) pump???? Don't even know why it has a electrical pump in the 1st place ??? ----Thanks---Mike..Tampa Bay!!!

Well there are a number of things to keep in mind. One the coast guard says there needs to be a shut off valve or anti siphon valve at the tank. The ground wire on an electric pump should go to a oil pressure switch. The pump must not continue to run if the key is on the the engine is off. Most often the pump is mounted directly after a filter low in front of the engine on production engines.

It should not take too much to relocate a pump. You can damage an electric pump running it dry.

Your new engine probably doesn't have a mechanical pump option. If it is an aftermarket block it may.

thanks again----I will see my buddy this next week----look over the boat and think about the points you brought up---The motor we believe is original 1995 Outlaw 454/330 hp----it was just recently rebuilt-not brand new as I think I originally stated !!!!!