Primer bulb going flat

Discussion in 'Bubba's Outboards' started by Mac-b, May 14, 2009.

  1. Mac-b

    Mac-b Moderator Staff Member Supporting Member

    Messages:
    19,259
    State:
    North Caro
    I have installed a 200 HP four stroke on a ten year old boat and the primer bulb is going flat after a few minutes of running time at 4200 RPM. No problem at idling speed. I think I have problem in the gas tank, but I'm not sure. Any advice would be welcomed before I take it to the shop.
     
  2. boohoo222

    boohoo222 New Member

    Messages:
    20
    State:
    georgia
    make sure the gas tank vent is all the way open, not partually blocked
     

  3. Mac-b

    Mac-b Moderator Staff Member Supporting Member

    Messages:
    19,259
    State:
    North Caro
    It has a 60 gallon built in tank. I can blow thru the vent hose, so I assume that it is open.
     
  4. brownie525

    brownie525 New Member

    Messages:
    1,505
    State:
    Nj
    theres an air leak somewhere check over all of the connections. when you run the motor then shut it off for a half hour or so does it can you start it right back up or do you have to prime it first?
     
  5. metalman

    metalman Well-Known Member

    Messages:
    3,447
    State:
    IN
    Name:
    Winston
    Mac,
    Have you tried removing the bulb from the line to eliminate bad valves in the bulb?

    Does it have a water separating filter or any other kind of filter between the tank and the bulb? If so, is it rated to pass enough fuel for your motor? If it is rated high enough, change the element.

    Are the hoses and fittings big enough for your motor?
    Is the hose pinched, squashed or old enough that it could be degrading inside and collapsing?

    The only way the bulb can be sucked flat is if more is being taken out of it than can get in it.

    Eliminate the tank breather completely from the equation by opening the filler cap when running. You may have to have somone hold something in front of it to prevent water splashing in.

    If the bulb still sucks flat something is blocked or restricted. It could be anywhere from the pick up in the tank to the inlet of the bulb.

    You could fit a new bulb and line and run it from a clean gallon can just to eliminate the entire gas tank and boat fuel system just to prove a point.
    If the motor is injected, don't run it too long on unfiltered fuel, the injectors don't like it!
    Assume nothing, check everything...W
     
  6. Mac-b

    Mac-b Moderator Staff Member Supporting Member

    Messages:
    19,259
    State:
    North Caro
    First, I would like to thank all you guys for your suggestions.

    I went and got myself a portable gas tank with the proper connections, filled it with gas. Then I attached it to my fuel line and the same thing happen, primer bulb went flat. So, one thing I knew for sure, it was not my gas tank on the boat. Then I started taking off all the hoses that were installed for the new motor. The first hose was what was causing the problem. I could barely blow thru it and when I looked inside one end I could see what looked like a spring with a rubber flap. I replaced this hose with an old one I had and everything is now the way it should be. It takes the gas and runs like a Honda should. Happy day are here again.

    The faulty hose was a Trident marnine fuel hose, barrier lined.

    I did not want to drive one hour and forty five minutes back to the dealer, thats why I did all the work that I did. Just called him and told him that I had solved the problem and he owed me, he said he sure did and he is sending me some Honda in line filter systems and some other stuff via UPS.
     
  7. boohoo222

    boohoo222 New Member

    Messages:
    20
    State:
    georgia
    now ive learned something
     
  8. brownie525

    brownie525 New Member

    Messages:
    1,505
    State:
    Nj
    :big_smile:eek:ops for some reason i thought you ment that the primer bulb was going soft, should have read the post better lol:big_smile: