Motor dies

Discussion in 'Outboard Maintenance' started by fishhawk, Jan 25, 2010.

  1. fishhawk

    fishhawk I Love microskiff.com!

    51
    0
    331
    I have a KW Stealth with a 1994 115hp yamaha 2 stroke. My problem is I can run about 2mi. at 4500rmp and the motor will start to buck and then shut down. I wait about 30 second pump the ball and she'll run about a 1mi. and do it again, the longer I wait to restart the motor the longer she'll run. I have connected a portable 6 gal. tank to motor and it runs with no problem. I have also checked the inboard gas tank vent and it is clear. Any suggestions out there?
     
  2. Frank_Sebastian

    Frank_Sebastian Well-Known Member

    787
    2
    391
    Does the bulb collapse when it dies? If so there is a check valve in the tank feed that may be partially blocked. If not then I would suspect an air leak somewhere in the fuel line.

    Best regards,
    Frank
     

  3. Frank_Sebastian

    Frank_Sebastian Well-Known Member

    787
    2
    391
    One other thing I thought of is a clogged screen in the pick up tube in the tank.

    Frank
     
  4. Brett

    Brett > PRO STAFF <

    If it runs fine on another fuel tank and hose,
    then you know it's a fuel system problem.
    15 year old fuel lines? I'd replace them from tank to engine.
     
  5. fishhawk

    fishhawk I Love microskiff.com!

    51
    0
    331
    Frank, fuel ball does not collapse I also was thinking air leak. Brett, rerouting a new gas line sound like fun but I'm sure it isn't. I'm going to try some new hose clamps and a new ball tomorrow. I was able to blow air in the gas hose from motor to tank. I know this will not tell me if there is a air leak or not, but at least the line is clear. I forgot to mention there is a water seperator also in the gas line, could this be a problem.
     
  6. Brett

    Brett > PRO STAFF <

    Air leaks can occur anywhere from the fuel tank to the carb inlet.
    Finding the leak is entertaining. Previous post...

    http://www.microskiff.com/cgi-bin/yabb2/YaBB.pl?num=1259293416/2#2
     
  7. mark_gardner

    mark_gardner I Love microskiff.com!

    sounds like she's starving for fuel, when you stop to pump it all's good till she runs out or isnt able to keep up with the flow??? possibly because of a clogged filter??? , if you cant remember how long its been since changing the filter then that needs to be done for sure and also at your earliest convienence i would definitely change out the fuel lines. good luck
     
  8. anytide

    anytide Administrator Staff Member

    4,129
    532
    1,968
    x2 filter?
    -anytide
     
  9. fishhawk

    fishhawk I Love microskiff.com!

    51
    0
    331
    Thanks for all the help guys. I will be working on the motor this week, I'm putting the boat up for sale. I bought the Native skiff that was on ebay.
     
  10. fishhawk

    fishhawk I Love microskiff.com!

    51
    0
    331
    I replaced ws filter, didn't replace gas line. Took a ride ran like a raped ape for about 3mi. then shut down I looked back and gas line ball was collapsed. You guys got any suggestions.
     
  11. Brett

    Brett > PRO STAFF <

     
  12. fishhawk

    fishhawk I Love microskiff.com!

    51
    0
    331
    I hear ya I hear ya, man thats going to be a job! 15 years of being a electricain and I don't know if I can fish the hose up to the tank.

    If there was an air leak in the gas line would the ball collapse.
     
  13. Un-shore

    Un-shore Well-Known Member

    connect the new hose to the old with a fitting and pull the old hose and the new will follow.
     
  14. fishhawk

    fishhawk I Love microskiff.com!

    51
    0
    331
    sounds like a plan, I'll give it a try ;)
     
  15. Brett

    Brett > PRO STAFF <

    One other thing to look at...as Frank said before,
    the pickup tube can be blocked down in the tank.
    The screen over the opening on the underside of the tube
    can be covered with sediment or varnish deposits.
     
  16. fishhawk

    fishhawk I Love microskiff.com!

    51
    0
    331
    Tried getting the pickup tube off the tank, no go. Now I'm thinkn about blowing air down the pickup tube. Any input?
     
  17. MATT

    MATT Well-Known Member

    Dude, You got old fuel lines and have been running e-10 gas...Buy some of the gray fuel lines and call me I will help with the replace job...
     
  18. fishhawk

    fishhawk I Love microskiff.com!

    51
    0
    331
    Frank thanks for stopping by and the help. I 'll be trying to get the gas out of the tank tomorrow. Hope to save some of the gas.
     
  19. Frank_Sebastian

    Frank_Sebastian Well-Known Member

    787
    2
    391
    Great to meet you Bud. I hope the fuel salvage project goes well. I have punches that can cut the opening for the fuel gauge if you need to fabricate a proper patch for the top of the tank.

    Should we post what was found and the solutions to date?

    Best regards,
    Frank_S
     
  20. Brett

    Brett > PRO STAFF <

    I'd like it, I never turn down the opportunity
    to see what caused an engine problem and what solved it.
    Might have to deal with it myself one day.