View Full Version : 04 outback ls sputters and backfires

06-05-2014, 12:39 PM
I am new so help me out!
My 2004 OUTBACK LS (330 FI) has starting having an issue with running after you have ran awhile and shut off.
I will give a scenario: Put the boat in the water, it will start up and run fine as long as you want. Turn it off and sit a little bit and when you start back up, it will crank fine but as soon as you put throttle to it, it starts sputtering and backfiring.

Mechanic has told me that he cant get it to do this, but he is crazy. It is like the boat isnt getting fuel or something has got hot and breaking down

its driving me crazy! Any suggestions?

06-05-2014, 12:51 PM
this sounds like the infamous vapor lock issue.

06-05-2014, 01:50 PM
i think mine does that too.. the vapor lock when all the heat coming off your motor, then heating up your fuel pump..throw a cold rag on it when you start and it should help bring that temp on the fuel pump back down. mine does that and of course my pump is mounted right next to the motor

06-05-2014, 04:01 PM
Thanks a bunch! I will try the rag trick! But what is the best way to prevent vapor lock?

06-05-2014, 04:09 PM
Run the blower.

06-05-2014, 04:10 PM
Take a look at this thread.


I'm not sure if your setup is the same, but noticed on mine a hot water line as well as oil lines were touching the fuel pump. I moved them away as suggested and didn't have an issue next time out. I have not completely tested it in a full day scenario yet though.

06-05-2014, 09:21 PM
I have a question regarding this issue? Is this the first tank of gas this season? I had this issue a couple seasons back and it turned out it was the gas. I drained the fuel out , added fresh gas, added a can of Seafoam, to help remove any moisture , changed the Fuel filter and problem solved. Maybe You have moisture in the gas???

06-06-2014, 07:33 AM
Mine does it once or twice a season, when I run it hard and forget to leave the blower on when we stop. I just get a cup of Ice water out of the cooler and pour it in the vacinity of the 2 fuel pumps and it's healed!

06-06-2014, 12:40 PM
It was the 2nd tank this season and I always keep stabilizer in the fuel, hopefully to prevent moisture. At this point I am not ruling anything out. I haven't changed the fuel filter this year but will do so this weekend. I am going to take the boat for a run tomorrow and take all the advice that has been given and hopefully solve this problem!

I will update soon!

06-06-2014, 02:20 PM
Don't forget to change your fuel filter also.

06-09-2014, 07:07 AM
I looked around fuel pump area for any lines that could be causing me problems. I found none, so I changed the fuel filter while I was in there and decided to go to the lake. I ran the boat for about 2 hours and cut it off and swam for probably 30 minutes. I ran the blower and opened the hood up while swimming and wouldn't you know. The boat fired right up and ran like a champ!!!! Ran again all day Sunday. Pulled kids on tube all day and ran the blower and if we stopped I popped the hood and again....It ran like a champ!!!!

Thanks for all the help, I hope I can return the favor sometime.