Long cranking Suzuki

Discussion in 'Bubba's Outboards' started by JDWILLIS39, Sep 25, 2009.

  1. JDWILLIS39

    JDWILLIS39 New Member

    Messages:
    422
    State:
    NC
    2008 Suzuki 90 HP 4 stroke. Cranks instantly in morning. but once in while on lake it just cranks and cranks 25/30 seconds and will wind up having choke it. Seems to happen after fairly long run. Normally never have to choke it even if has been sitting for days just turn key and its running.
    But long cranking just happens once in while. Most of time cranks quicker than you can turn the key. Any ideas is it something to worry about. May not happen once a day and some days not at all.
    Thanks for input.
     
  2. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Some where in there she is either loosing fuel prime or the electrical system is shutting something off. I am betting on fuel though.
     

  3. JDWILLIS39

    JDWILLIS39 New Member

    Messages:
    422
    State:
    NC
    OK I think you are right. Ethanol is in all gas here (use marine Stay-Bil) so I am going change fuel filter and see how that effects things. It has not been changed but not lot of hours on motor.
    Thanks Bubbakat I will let you know how turned out.
     
  4. Longjohn119

    Longjohn119 Well-Known Member

    Messages:
    1,203
    State:
    Iowa
    I think this is more for inboard motors but the principles are the same for outboards

    ETHANOL PROBLEMS

    By Robert Van Brunt
    Chief Petty Officer U.S.G.G. ret

    ETHANOL AND VAPOR LOCK

    Short description:
    When the engine compartment becomes hot either by climate or idling, and you use ethanol-blend gasoline it can cause excessive vapors in your fuel line and starve the engine of fuel. The engine can run poorly or stop and will not run until the fuel condenses.

    THE PROBLEMS

    Vapor Lock

    Fuel containing 10% ethanol is called E10. If you have ethanol in your gas, you run the risk of creating vapor lock because of excess vapors.

    Ethanol “boils” at 87ºF (at normal atmospheric pressure) and turns from a liquid to a gaseous state. By comparison, most automobiles have their fuel pump in the gas tank, so the whole system remains under pressure unlike boats whose fuel tanks are vented. In a closed system, the higher pressure raises the flash point of the ethanol reducing the amount of vapor that is produced. In addition, most automobile fuel lines are outside of the vehicle allowing them to stay cooler.

    Since most boat fuel lines are in the enclosed space (sometimes even insulated) of the engine compartment, normal ventilation will not cool the fuel significantly enough to avoid the potential problems of vapor lock. Furthermore, since the fuel pump in a boat is mounted on the engine (versus a car where the pump resides in the tank) the action of the pump can reduce pressure in the tank to below atmospheric pressure and further reduce the flash point.

    Boat engineers are aware of this problem and are reducing the likelihood of this occurring by reducing the suction required by the fuel pump, minimizing hose fittings and bends, and including a quality anti-siphon valve. In existing boats, fuel lines and filters should be kept as low in the boat as possible and tank vents should be cleaned and open.

    Heat Soak

    Most boats have “forced” ventilation. Air moves through the engine compartment when the boat moves forward. Heat soak happens after you have been at high RPM and then stop or drift on idle for a while. Because of heat soak the engine compartment will rise to a point where the ethanol will boil

    THE CURE

    To prevent vapor lock (i.e. boiling ethanol):

    1. Make sure the engine compartment has adequate ventilation.
    2. Relocate fuel lines to be low in the bilge. (The bilge is cooler because it is in direct contact with the water.)
    3. Monitor the engine compartment temperature.
    4. Add (or turn on) engine room blowers.
    5. Keep the tank vent clean and unobstructed.
     
  5. JDWILLIS39

    JDWILLIS39 New Member

    Messages:
    422
    State:
    NC
    Seems lot on track with my problem. If engine has sat for long time always cranks. Will keep in mind but not lot I can do to lower temps any more. But sure fits in with the problem I been having. Going change fuel filter and take look at everything.
    Good info Thanks a lot.
     
  6. SWeiss

    SWeiss New Member

    Messages:
    751
    State:
    Pennsylvania
    This E10 corn fuel is nothing but a giant pain in the ass. You pay the same amount for it as conventional gasoline and you get 10-15% less MPG out of it.

    In turn you have to buy MORE to go the same distance and burn up as much gasoline as you would in the first place. Where is the environmental benefit?
     
  7. catfishcrazee

    catfishcrazee Member

    Messages:
    52
    State:
    illinois
    i have a 2005 suzuki 90 hp four stroke, had the same problem, it was vapor lock, fought it the first summer, :angry: finally they put an inline Holly fuel pump on mine, took care of the problem. you think that suzuki would of corrected that problem by now. :confused2:
     
  8. slimdaddy

    slimdaddy Well-Known Member

    Messages:
    2,603
    State:
    Nelsonville, Oh
    Name:
    Keith
    ive heard there going to do away with the e-85 crap ihaul gas and we have a couple stores that have it and they dont sell enough of it to even mess with it may be 30 or so cents cheaper but you get 30%less mileage out of it so it aint no cheaper i wish they would just stay with str gas which is getting hard to find marathon is the only rack that we can get it sun ,valero citgo has done away with it completely
     
  9. JDWILLIS39

    JDWILLIS39 New Member

    Messages:
    422
    State:
    NC
    Thanks catfishcarze that could save me lot of trouble. In light all this info will have re-think whole problem. Thanks for the info.

    South Carolina is 10% Ethanol everywhere almost impossible to find gas without it.
     
  10. playin4funami

    playin4funami New Member

    Messages:
    4,104
    State:
    Saronville Ne.
    I had the same thing go on,it wasn't the gas(type). After a long run it would have to crank a few seconds before firing,but on short runs it would fire at the touch of the key. My boat guy played with it for a couple days and told me after making a long run then shutting down the heat from the motor would not dissapate as when it was running and moving,creating a heat sink out of the carbs,etc. which was cooking the gas right out of the carbs after being shut down,so it had to reprime itself on start-up. Solution- before arriving at spot slow down and run slow for awhile before shutting off the motor. still happens now and then but it is nothing to worry about. He suggested just playing with it if it bothered me by trying different things,like letting the motor idle and cool down more before shutting off,and other things like that.
     
  11. JDWILLIS39

    JDWILLIS39 New Member

    Messages:
    422
    State:
    NC
    [QUOTE=playin4funami;1663983]I had the same thing go on,it wasn't the gas(type). After a long run it would have to crank a few seconds before firing,but on short runs it would fire at the touch of the key. My boat guy played with it for a couple days and told me after making a long run then shutting down the heat from the motor would not dissapate as when it was running and moving,creating a heat sink out of the carbs,etc. which was cooking the gas right out of the carbs after being shut down,so it had to reprime itself on start-up. Solution- before arriving at spot slow down and run slow for awhile before shutting off the motor. still happens now and then but it is nothing to worry about. He suggested just playing with it if it bothered me by trying different things,like letting the motor idle and cool down more before shutting off,and other things like that.[/QUOTE]

    One theme is that it is a fuel problem. I am going do some looking and checking/testing but I suspect a heat/fuel problem likely worsened by ethanol gasoline. Thanks guys for all the insight. We do not have local Suzuki dealer around here that I could deal with. If I find anything useful I will post it. But windy weather here next few days sitting on bank watching. Tight lines.
     
  12. JDWILLIS39

    JDWILLIS39 New Member

    Messages:
    422
    State:
    NC
    I looked it all over and studied the problem and I have come to the conclusion that in my professional opinion it is a design problem with the Suzuki motor. the fuel line is routed not once but twice against the block and manifolds. After long runs or hard use the heat build up would likely make fuel system lose prime especially since using 10 ethanol gasoline. The hose is protected with cover to prevent damage but no heat shields. She is going get hot on shutdown. If gets to be a big problem I may try rerouting hoses but for now I am going live with it and since I know what the problem is, see if I can work around it. Thanks for all the help gentlemen. See you on water.
     
  13. trnsmsn

    trnsmsn New Member

    Messages:
    1,214
    State:
    Missouri Originally Now I
    I know you said earlier that you had to choke it. My 2000 70HP, 4 stroke Suzuki is fuel injected & what would be the choke button on the controls, does nothing. If it is & should be fuel injected then vapor lock shouldn't be as much of a concern, due to the fact that it is a VERY high pressure fuel system.

    Try cycling the key a few times before cranking it next time it occurs & see if it helps out, if so, this would be a priming issue.

    HTH, Elliot
     
    Last edited: Oct 6, 2009