CaptainMax
Cadet
- Joined
- Aug 20, 2012
- Messages
- 16
Hi Guys! I've posted here before and you've all helped so much, so to begin...thank you. Also, I want to say I've scanned the forums and looked for a similar problem to mine, and have found a few similar but nothing quite the same, so I decided to post. Here goes:
1990 Four Winns OMC Cobra 5.0 HO
Let me try and explain the issue I've been having, and then I'll tell you how I've tried to fix it.
I get out to the lake and my boat fires right up! Its a beautiful thing. No issues at all. I can run the boat at WOT all day. She purrs like a champ! After running her for 15 maybe 20 minutes or so, I decide to go to the beach, or whatever, and I shut the boat off. When I go to restart the boat, she will fire right up no problem, run for a short while (I mean like 100 yards or less) and then die. I can not get it started after this!
Here are some of the things I've done: I replaced the anti-siphon valve. I've replaced the fuel filter (fuel/water separator). Also, and this may be quite interesting, after the boat died, I pulled the fuel filter to check it, and it is only 1/2 full! I'm assuming (and PLEASE correct me if I'm wrong here) that means that when I shut the boat off, the fuel system is losing pressure and subsiding back into the tank. I dont see any signs of gas in the bildge or anywhere else. If the system WERE NOT losing vacuum pressure, the fuel filter should still be full, right? I'm also assuming that the reason the boat runs shortly after being turned off, is there is still gas in the Carb bowl.
As a test, I eliminated the fuel filter from the system because after the boat would die, I mechanically pumped fuel through the lines with a hand pump-ball. It seemed to lose pressure at the fuel filter. Based on my test, and eliminating the fuel filter, the boat seemed to perform just fine. Since my fuel filter is BRAND NEW, I assume that the bracket holding the filter must have some sort of crack in it allowing air into the system?
Here is what I cant figure out though, and this really trips me up. Even if I lost pressure in the fuel system when I shut the boat off, why isnt my fuel pump bringing the gas back up when I try to start the boat? The fuel pump is new and replaced just last year!
More questions/mysteries to me: isnt the whole purpose of the anti-siphon valve to not allow gas to fall back into the tank? Could I have put the wrong valve on when I replaced it two weeks ago? It screwed in just right. Could this problem be caused by a clogged gas tank vent line? Could this be caused by a bad fuel pick-up in the tank?
Remember, the boat will run juuuuuuust fine all day as long as you dont shut it off. Its only when I shut it off.
Anyway, all the help I can get is greatly appreciated, and if you have more questions to help you try and solve the problem, please ask away!
1990 Four Winns OMC Cobra 5.0 HO
Let me try and explain the issue I've been having, and then I'll tell you how I've tried to fix it.
I get out to the lake and my boat fires right up! Its a beautiful thing. No issues at all. I can run the boat at WOT all day. She purrs like a champ! After running her for 15 maybe 20 minutes or so, I decide to go to the beach, or whatever, and I shut the boat off. When I go to restart the boat, she will fire right up no problem, run for a short while (I mean like 100 yards or less) and then die. I can not get it started after this!
Here are some of the things I've done: I replaced the anti-siphon valve. I've replaced the fuel filter (fuel/water separator). Also, and this may be quite interesting, after the boat died, I pulled the fuel filter to check it, and it is only 1/2 full! I'm assuming (and PLEASE correct me if I'm wrong here) that means that when I shut the boat off, the fuel system is losing pressure and subsiding back into the tank. I dont see any signs of gas in the bildge or anywhere else. If the system WERE NOT losing vacuum pressure, the fuel filter should still be full, right? I'm also assuming that the reason the boat runs shortly after being turned off, is there is still gas in the Carb bowl.
As a test, I eliminated the fuel filter from the system because after the boat would die, I mechanically pumped fuel through the lines with a hand pump-ball. It seemed to lose pressure at the fuel filter. Based on my test, and eliminating the fuel filter, the boat seemed to perform just fine. Since my fuel filter is BRAND NEW, I assume that the bracket holding the filter must have some sort of crack in it allowing air into the system?
Here is what I cant figure out though, and this really trips me up. Even if I lost pressure in the fuel system when I shut the boat off, why isnt my fuel pump bringing the gas back up when I try to start the boat? The fuel pump is new and replaced just last year!
More questions/mysteries to me: isnt the whole purpose of the anti-siphon valve to not allow gas to fall back into the tank? Could I have put the wrong valve on when I replaced it two weeks ago? It screwed in just right. Could this problem be caused by a clogged gas tank vent line? Could this be caused by a bad fuel pick-up in the tank?
Remember, the boat will run juuuuuuust fine all day as long as you dont shut it off. Its only when I shut it off.
Anyway, all the help I can get is greatly appreciated, and if you have more questions to help you try and solve the problem, please ask away!