Jump to content

Welcome to TheMalibuCrew!

As a guest, you are welcome to poke around and view the majority of the content that we have to offer, but in order to post, search, contact members, and get full use out of the website you will need to Register for an Account. It's free and it's easy, so don't hesitate to join the TheMalibuCrew Family today!

Boat Dies with a full tank of fuel

Recommended Posts

I have a 99 Sportster LX and have had mechanics look at it etc etc. Problem still exists. If you put more than a 1/2 of tank of fuel in the boat it dies and will not start for some time. If you run 1/2 tank or less I never have a problem runs great never dies. When the boat quits running its as if you pulled a kill switch it wont fire or do anything. Then after minutes to hours pass it fires. Then it will eventually die again until you get below 1/2 tank. Does anybody out there have any clue what could be happining? I would appreciate any input. Thanks!

Link to comment

If you are positive it is related to the fuel level, check the fuel lines as they round the lower back corner under the fuel tank and head up. The fuel tank sags as fuel increases in it and can pinch off the fuel line if it's not held down below that corner. If you open the floor panel under the rear seat and look back under the fuel tank you'll see where the fuel lines run along the stringer and then turn and go up behind the tank. Look right at the turn to see if they are getting pinched.


Link to comment
  • 2 weeks later...

Another good place to look maybe your vent lines. If the tank is full and a vent line is pinched or plugged then when the engine demands more fuel the pump will be working harder to overcome the negative pressure in the tank. When the tank is half or less there is more freespace to hold air and the tank will not be as easy to pull into a vaccum. every drop of fuel that is taken out of the tank has to be replaced with air at the same rate or faster or it will try and cavitate.

Link to comment

I checked the fuel lines they seem fine. However I had a strange thing happen after adding 5 gallons of fuel from a pump which enters the tank much faster than pouring from a container the boat died on take off. I fired it back up and it was good the rest of the night. It has never died with that little fuel in it but it has been a couple of years since I bought gas on the lake.

RE: the vent lines being plugged I tried running with the fuel cap off and still ran into problems. Would that allow enough air in the tank to keep from having a problem? How can I clear the vent lines if they are plugged?

I am back to the drawing board regarding this problem. Any help would be appreciated! Thanks!!!!

Link to comment

Maybe it is the kill switch. When it dies and won't start, are the gauges working or dead? No gauge function and no ignition while engine cranks could be kill switch in open posistion. If this is the case, try pushing in on the kill switch while cranking engine.

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...