Fuel delivery issues

[mperkins122]

I have an 86 150 GT OB. When I start it, all is well. Then at some point during accelleration, it begins to lose fuel. The only way to keep it running is to keep pumping the bulb quickly. If I fully accelerate, it takes off and runs fine. Its from 5-25 mph that it dies. I replaced the bulb thinking it loses pressure but the new one does it too. Could it be trash in the bowls? Fuel line collapsing? Tank trash? The Fuel bulb does get hard but while running it softens more than I think it should. Thanks in advance for the help

Mike

 

[tbull]

Re: Fuel delivery issues

Does your outboard have a fuel pump? I experienced the same problems when I first got my boat. I rebuilt the fuel pump and replaced all the lines and the bulb. Also cleaned out the tank real good, problem went away. If you suspect your carbs are dirty it's a good idea to take them apart clean and rebuild them. Not sure what exactly cured the problem, but hey who cares right? It's fixed...

 

[Jayboid]

Re: Fuel delivery issues

The primer bulb is supposed to get softer when you are underway, so that's no problem. However if it flattens out, that means you have a fuel restriction somewhere between the bulb and the gas tank.

If it doesn't flatten out, more likely you have an air leak at one of your hose fittings or a worn gas hose. In that case, the fuel pump pumps air as well as gas, not getting enough gas to keep your carb float chambers full. To test this, hook up an auxillary tank close to your motor. If that takes care of the problem, then you have an air leak. If not, you should suspect the fuel pump.

 

[mperkins122]

Re: Fuel delivery issues

I just had the carbs done a month ago. Also, I want to replace my fuel pump from the VRO style b/c I premix now anyways. What fuel pump do I need to use. Also wouldnt a fuel pump have the problem completly through acceleration? After 25mph-WOT, you no longer have to pump the bulb to keep going as if the high speed jets are supplying enough fuel. P.S. no fuel trail is in the water, the fuel pump doesnt hiss or leak when inspecting it while priming. could it be an obstruction in the lines/tank/pick-up tube??

 

[HighTrim]

Re: Fuel delivery issues

The problem is likely the fuel pump, as indicated by your statement "The only way to keep it running is to keep pumping the bulb quickly." You are acting as the fuel pump while doing this.

 

[mrcj001]

Re: Fuel delivery issues

If you have a inboard fuel tank, check the pick-up tube inside the tank. After a while they will dry-rot and at the top they begin to crack and suck vacuum. sometimes fall off completly.

 

[mperkins122]

Re: Fuel delivery issues

Thanks for your help. Will look into it tonight. Any other suggestions are appreciated