Possible vapor lock

Discussion in 'Blog' started by twright, Sep 9, 2015.

  1. twright

    twright New Member

    4
    Sep 8, 2015
    Missouri
    2000 230 signature open bow.
    5.7 mercuries
    New Sea Ray owner and so happy. I bought a 2000 230 open bow. Took it out this past weekend for the first time. Here is my problem. I ran it for over an hour. Then when we tied up for about 30 to 45 min's. Went to start it and cranks over and over but won't start. Got towed back in and had a mech come look at it the next morning. That morning it fired right up. He thought a good start was to replace fuel filter. He said it was clear and no contaminated. Took it out for the day and when it got hot it did it again. Would not start. Open the throttle body based on mech recommendations. Would not start. After about 1/2 hour with engine cover open it started. Mech thought it might be vapor lock. Any suggestions? Talking to other boaters thought thermostat issue. Boat temp holds at 170 after running for hours and after sitting for a few hours it only dropped to 130. New owner needs help? Thanks
     
  2. rmlsll

    rmlsll Member

    146
    Oct 11, 2009
    Saugatuck MI / Cape Coral FL
    340 Sundancer 2004 /
    240 Sundeck 2007 /
    10' Zodiac
    Twin 8.1 merc,. V-Drive /
    5.0 merc., bravo 3
    Had similar problem w/ merc 4.3. Blamed it on a buddy that put gas station ethanol gas in it. When I finally got about 60 gal of good gas back in it I had no more problems.
     
  3. twright

    twright New Member

    4
    Sep 8, 2015
    Missouri
    2000 230 signature open bow.
    5.7 mercuries
    Thanks for the advise. That could b it
     
  4. scoflaw

    scoflaw Well-Known Member

    Aug 10, 2011
    cape cod mass
    1999 Powerquest legend 260 sx
    502 mpi Bravo 1
    doubtful, gas is gas. Try spraying carb cleaner down the throat of the carb or tbi when it's doing this.
    Sounds like vapor lock
     
  5. paulswagelock

    paulswagelock Well-Known Member

    Oct 25, 2010
    pa
    2018 SDX 270 OB 300 Verado
    Verado 300
    Ethanol based gas will vapor lock at a lower temperature than non ethanol gas.
    some suggestions- idle for a bit at the end of a long run, run the blower for a while after you shut down to cool off the temp in the engine compartment. All else fails, put a low pressure pump in line if you do not already have one.

    i am not sure it is vapor lock as that is not really all that common. Could be an ignition issue that cuts out when hot. You should check for spark next time it happens to rule out other issues. As mentioned above, you could spray a little carb cleaner in the throat when it is happening and if it does not try to fire, it is not a fuel issue.
     
  6. scoflaw

    scoflaw Well-Known Member

    Aug 10, 2011
    cape cod mass
    1999 Powerquest legend 260 sx
    502 mpi Bravo 1
    If you figure out it is vapor lock, that make a heat shield you can wrap your fuel lines with . Your not saying much about which fuel delivery system you have
     
  7. scoflaw

    scoflaw Well-Known Member

    Aug 10, 2011
    cape cod mass
    1999 Powerquest legend 260 sx
    502 mpi Bravo 1
    After rereading your post, you say throttle body. So if it's TBI not MPI, you should be able to see your fuel spray with the flame arrestor off. Verify that
     
  8. SeaRide

    SeaRide Active Member

    Oct 3, 2006
    Chapin, SC
    1999 230BR
    5.7 EFI/Alpha
    Tw,

    I had the problem once years ago. I was running along at 3200 rpm and the air temp was near 95 degrees. I shut the engine down and had it took several attempts to start. From that point forward, I have always let the engine run at about 1000 rpm in neutral with the blower on before shutting her down after a long run. Also, try a search under CliffA in the engine section or better yet send him a PM. He had a similar issue with his previous boat powered by a 5.7. FYI my 5.7 has run about a needle's width over 170 degrees since new.
     
  9. Raytard

    Raytard New Member

    17
    Mar 30, 2015
    Alberta
    97 Sea Ray 270 Sundancer
    2006 Crown Trailer
    08 Dodge 2500 deleted 6.7
    7.4 merc bravo 1
    If it is indeed tbi, look to see if fuel is spraying out the injectors (already mentioned) as it turns over.if it is, unplug the plastic clips to both injectors (takes 2 seconds) to stop the fuel flow and try starting it. If it fires, you have the same problem I did, which is that it was dumping to much fuel on the initial crank stage. I'm not sure if you mean In your original post that you left the throttle open as your stating it. But as a habit, after I park, and shut the engine down (no post idle needed). I reopen the throttle body to allow unburned vapours to escape. This way it gets a clean dry start when I'm ready to leave, be it 2 minutes or several hours. At least with the injectors unplugged, if it restarts temporarily, you can narrow it down to a fuel issue and not electrical.[​IMG]
     
  10. twright

    twright New Member

    4
    Sep 8, 2015
    Missouri
    2000 230 signature open bow.
    5.7 mercuries
    Good suggestion. It is an EFI fuel injected system.
     
  11. twright

    twright New Member

    4
    Sep 8, 2015
    Missouri
    2000 230 signature open bow.
    5.7 mercuries
    Yes the fuel is spraying in nicely. I will try your suggestion. Thank you so much
     
  12. scoflaw

    scoflaw Well-Known Member

    Aug 10, 2011
    cape cod mass
    1999 Powerquest legend 260 sx
    502 mpi Bravo 1
    Look for the spray when it's in the no start condition
     

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