115 six stack still starving for fuel

[Rienel]

well: I was in here the other day bout this. I have a 77 115 merc that seems to run out of fuel shortly after getting up to plane. I have rebuilt the pump,cleaned and flushed the tank, replaced the bulb and fuel connectors.when this boat starts to starve for fuel if someone pumps the bulb if takes off again if it idles for a while then it will go hard and get into plane again but runs out in a few seconds.I did a fuel pump check in the shop and i get 9 lbs and it holds well after shutting engine off. when i had the pump apart to check for debrei i noticed some droplets of water under the diaphram on the vacume side (is this normal?)I can drive around all day at idle or very low speed without problems.<br />Please any help would be appreciated.

 

[stargate3d]

Re: 115 six stack still starving for fuel

I had this problem too. You need to fix it fast, as this motor does not like that problem, you can burn the pistons.<br /><br />My problem turned out tto be a bad fuel bulb, for which I replaced it with a defective one. <br /><br />Here’s what you do. <br /><br />Get a buddy to sit near the bulb, when you take off and it starts to dies have the buddy squeeze the bulb with medium pressure, if the engine picks up then you have a bad, new bulb, or pump (I would guess the bulb first). You can by pas the bulb after priming for the day. If you have to squeeze the bulb very hard to keep the motor running then it is a carb float issue. DO NOT RUN THE MOTOR LIKE THIS idle back to the dock and get carbs rebuilt.

 

[The Marine Doctor]

Re: 115 six stack still starving for fuel

Any chance you have been using a fuel with alcohol content...Ie Mohawk or Husky.<br /><br />These fuels will tend to absorb water. This may be where the water is comming from.<br /><br />Also check the spark plugs for white cream...this is water present in the cyl.<br /><br />Try your engine with a different hose and tank.<br /><br />TMD