Results 1 to 11 of 11

Thread: Small outboard fuel problem

  1. #1

    Default Small outboard fuel problem

    Hi, I have an 80's era 6 hp Evinrude motor (2 stroke); not sure exact year. The motor will start fine, often without use of the choke on the first or second pull, even after sitting for months, but will die as soon as put into gear and given some throttle. Also, after idling for a about a minute or so, it often dies. We have to pump the fuel bulb to keep the motor running, and at that point it runs pretty rough. I just replaced the hose assembly with an OMC hose assembly, but no improvement. My next thing will be to get a new plastic tank; maybe air getting in the line? Do these motors have a fuel pump or something to keep the fuel flow going or is it just by the siphon principle?
    I also just replaced the spark plugs. BTW, it does have fresh fuel.
    Does anyone have an idea of what's going on or how to fix it?
    Thanks,
    Jim

  2. #2
    Member Dirtofak's Avatar
    Join Date
    Apr 2006
    Location
    Beaver Creek
    Posts
    2,267

  3. #3

    Default

    hey dirtofak, thanks for the quick reply! That doesn't look like any fuel pump I've ever seen! Is that a "do it yourself" repair?
    Thanks again,
    Jim

  4. #4
    Member
    Join Date
    Apr 2006
    Location
    chugiak, ak
    Posts
    630

    Default fuel hose from tank to motor.

    I had one of those motors back in the day, and the conection from the fuel hose to the motor was somehow messed up. i replaced it with a new one and poof, she ran like a champ!! I looked at the old fuel connection, and could see anything wrong with it. Before I replaced the connection, it did leak a little and ran just as you described. If you are going to replace the tank, might as well get a new hose too. I just replaced a hose and tank for my 78 seahorse and noticed there were different sizes of hoses for different yr motors. Might be worth checking out. The other option is take it to J Kimberly on artic, that guy is awesome with those motors!! Or just plain give him a call, great guys, incredible mechanics!

  5. #5
    Member AKBassking's Avatar
    Join Date
    Oct 2006
    Location
    SE Alaska-Summer Columbia River-Winter
    Posts
    2,007

    Default

    Along with all the other suggestions here, make sure your tank vent is open.

    ALASKAN SEA-DUCTION
    1988 M/Y Camargue YachtFisher
    MMSI# 338131469
    Blog: http://alaskanseaduction.blogspot.com/

  6. #6

    Default

    The Fuel pump on that is a diaphram style. It is not a pump like you would think, it uses the pressure changes in the crank case to flex a rubber diaphram that creates a high and low pressure side which in turn pumps fuel. I agree, check all the connections for the fuel line, make sure your vent is open and flowing (might be clogged) then if that doesnt work, look to the carb/fuel pump. I am not familiar with that exact motor but the carbs of that size and era are fairly similiar. The fuel pump should be a square plate situated on the side of the carb. You can take the side plate off and inspect the membranes. I would just change them all, for 12 bucks you will be ahead of the game, sometimes the membranes have small pin holes in them that you cant see but fuel can still get through. The carbs on those motors are really simple and easy to work on so you shouldnt need to take it to anybody if you are even remotely mechanical. Hope this helps.
    MTRR

  7. #7

    Default

    Thanks for all the tips guys. I did replace the whole hose assembly with an OMC hose assembly, thinking I was getting air in somewhere; I will get a fuel pump kit, dirtofak's link directed me to a company that has them; sounds pretty simple.
    I might have failed to mention that the only way to keep the motor running is to keep the bulb pumped up when the motor starts to cough. Looks like everything is pointing to the fuel pump. I will replace it, probably get a new tank as well as the plastic one I now have is pretty old (never hurts to have extra stuff anyway; I still have the old hose assembly, which is probably ok if the fuel pump is the prime suspect of this issue). BTW, the OMC hose assembly cost me 42.00 her on Kauai; everything is expensive here, even more than Alaska! Gallon of milk here can go over 5.00.
    Thanks again for all the help,
    Jim
    I will let you guys know the outcome of this motor!

  8. #8
    Member
    Join Date
    Apr 2006
    Location
    Juneau, Alaska
    Posts
    284

    Default Varnish in the Carb?

    I would do all of the steps everyone has suggested and if you still have problems you may have some old gas varnish built up in the carb. Especially if the carb hasn't been apart in all of those years. Needle valves can get fouled enough by old gas deposits to gag the engine - even if you are forcing gas through the carb with the bulb on the fuel hose. Just a suggestion to check out if the problems continue. Good luck!

  9. #9

    Default

    When you pump the bulb yourself does it run good, or does it run like a dog? I would guess the latter because you are probably partially flooding the engine when you pump it then it leans out as the fuel is used up. On thing to note, over pumping the bulb will rupture the membranes in your fuel pump, so when you get the new ones in, make sure to only pump the bulb until it is just firm, do not over pressure your fuel pump.\
    Good luck
    MTRR

  10. #10

    Default

    Actually, the motor runs like a champ, until it uses up the fuel in the line; at that point, the bulb is empty and must be pumped up to keep the motor running; thanks for the tip about over-pumping the bulb, never thought of that or the consequences. I did take it apart the other day (while the boat was sitting in the water; not too bright as I could've lost parts in the water!), but I was too curious; the membranes did look old, probably originals.
    Thanks guys!
    Again, as I progress, I'll post the results; I know a 6 hp motor is not a high priority on everyone's interest list, so I really appreciate you guys taking the time to help; have to say some of the most helpful people I've talked to have been thru this site; and have not personally met anybody! There is hope even in the day and age we're living in.
    Thanks,
    Jim

  11. #11
    Member AKBassking's Avatar
    Join Date
    Oct 2006
    Location
    SE Alaska-Summer Columbia River-Winter
    Posts
    2,007

    Default

    pickup screen in tank

    ALASKAN SEA-DUCTION
    1988 M/Y Camargue YachtFisher
    MMSI# 338131469
    Blog: http://alaskanseaduction.blogspot.com/

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •