Fuel Pump

[dstuard]

Well now that I have gotten all of my electrical problems solved I am having trouble getting fuel. When I went WOT it would run out of gas. I have put in a new gas tank and am sure all the fittings are tight and well vented. I also rebuilt the fuel pump. I can see it suck all the gas out of the fuel filter but it is not replaced. When I am not a WOT it just trickles into the filter but it looks like it quits when I go WOT. WHen I put the new gas tank it I went 5/16 hose from the tank to the valve on the side of the boat and 3/8 from there to the engine. COuld this be the problem or did I do something wrong with the fuel pump? It is also running rough like the carbs need adjusting when at idle. COuld this be the cause?<br /><br />Motor is 83 Merc. 115HP

 

[Hooty]

Re: Fuel Pump

Good way to check the job on the fuel pump is squeeze the priming bulb and see if the engine picks up and runs. If it does, the fuel pump may still be goofy or the filter maybe stopped up.<br /><br />c/6<br /><br />Hooty

 

[dstuard]

Re: Fuel Pump

I did that and it would keep going. What could I have messed up on the fuel pump. It sure seemed easy. What exactly do the check valves in it do. Is it possible to tighten the retainer on those too much and cause a problem and should they rotate pretty easy?

 

[rickdb1boat]

Re: Fuel Pump

Did you replace the bulb? Also, replace the filter as suggested.

 

[dstuard]

Re: Fuel Pump

Every piece related to the gas is new from the tank to the engine. I did just discover that I have no spark on 3,4 and 6. Could this be part of the reason I am not getting any fuel? Also what do I need to do to figure out why I have no spark?

 

[dstuard]

Re: Fuel Pump

Could I flip flop the switch boxes and see if the problem changes to 1-2-5? Is it possible to leave the switch boxes and just change the wires?

 

[dstuard]

Re: Fuel Pump

^^^

 

[mellowyellow]

Re: Fuel Pump

no fire means no gas.... pumps run off internal<br />pressure.<br />good luck,<br />M.Y.

 

[OBJ]

Re: Fuel Pump

Hi dstuard.<br /><br />It's very easy to mess up a pump job. The check valves in the pump let the fuel flow only in one direction, toward the carbs. Yes you can switch power packs and see if that will cure your spark problems. Maybe check your pump job or connections to crankcase.<br />Mellowyellow, I may be wrong here but, the fuel pump works off the press/vacuum created in the crankcase from the piston moving "backandforth". Even though there may be no fire on that particular piston, it's still moving backandforth still creating press/vacuum in the crankcase. Or am I seeing it wrong?