Need some diagnostic help!

Discussion in 'Bubba's Outboards' started by Matt Smith, Apr 10, 2006.

  1. Matt Smith

    Matt Smith New Member

    Messages:
    119
    State:
    Tennessee
    I have a 1980 model, 25 Evinrude. Today while fishing with another BOC member, my motor all but quit running. We fished all morning going from spot to spot with no problem. At the last hole, and furthest downstream we got, we decided to pack it up and head back to the ramp. I started the motor, gave it gas, and had just began to plane when it bogged down and quit. I immediately restarted the motor, gave it gas, and it promptly died again. It would idle all day long, though. That's how we got back to the ramp. 4.5 miles per hour for about 5.5 miles, upstream of course and into a headwind. But I digress.

    My thinking is it's the carb, but I have had no prior trouble and as stated above, no problems at all today until when we were ready to leave. Pumping the bulb helped very little. Almost unnoticeable. And I have fresh gas in the METAL tank. Anyhow, before I go tearing into the carb, I would like some more experienced opinions.
     
  2. Mr.T

    Mr.T Active Member

    Messages:
    2,554
    State:
    MO
    Dirty gas. Dirty fuel filter. Blocked fuel line. Dirty carb.

    When it dies at full throttle, it's usually because it can't get enough gas. Figure out where the restriction is and you'll find the problem.

    Think there was a thread in the last few days with very similar symptoms and the usual great info from Bob and Bubbakat.
     

  3. Mutt

    Mutt Administrator Staff Member Supporting Member

    Messages:
    18,950
    State:
    Ca
    Name:
    Mutt
    Also on one motor i had it was to lean on the high end mixture readjust it ran like a top after that
     
  4. copycat

    copycat New Member

    Messages:
    1,841
    State:
    New Jersey
    It is possible that the carb is to lean on high end needle but I don't think thats your problem because it ran fine for most of the day. It is probably a dirty filter, clogged fuel line also it could be an air leak in the line or at the carb, but if it stalls at high throttle and runs fine at idle than the carb is not getting the fuel flow it needs when running it open.
     
  5. Mutt

    Mutt Administrator Staff Member Supporting Member

    Messages:
    18,950
    State:
    Ca
    Name:
    Mutt
    thats what i figured with mine it ran fine all day idled well then started to poop out at higher rpms id check the fuel filters and stuff first for sure. good idea to change em out anyways if they havint been in a while i change mine 2 times a year.
     
  6. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Pull your pick up tube out of the tank and see if it is clogged if not the take the line from the fuel pump to the carb and see by pumping gas thru it if it delivers enough gas. There could be some trash under the needle seat and you can take a squirt bottle with some gas mix in it and while running with the boat in the water under pressure spray some in the carb while trying to accelerate it. If that brings the rpms up then I suspect trash in the carb.
     
  7. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    There's no high speed adjustment in that carb.

    Check the screen in your fuel pump for trash.

    If you find any, put an inline filter in place, between the bulb and the engine.

    If that tank's not new, dump the gas in a bucket and check out the inside for rust.

    I've know people to store gas in a container and empty that container into their gas tanks, dumping stored trash and water with the gas. Never empty a container.

    Follow Bubba's instructions on checking the carb.
     
  8. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
  9. Hootowlc3

    Hootowlc3 New Member

    Messages:
    409
    State:
    Florida
    I had a 75 hp motor that did the same thing and it was the bulb.
     
  10. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Yes it could be other things. We can only give you what advise that comes from your explanation.

    Without actually being there and doing hands on diagnostics, it's educated guessing.

    We don't do haircuts over the internet either. That's even more difficult.

    Thanks for pointing out another option, Hoot.

    Check out your engine fuel lines for being soft and mushy. They deteriorate from the inside out and can clog the carb. They should be replaced periodicly for good maintenance.
     
  11. TDawgNOk

    TDawgNOk Gathering Monitor (Instigator)

    Messages:
    3,365
    State:
    Tulsa, Oklahoma
    Yeah, I want it short, up off the ears, no side burns, and thinned....

    Oh wait, no hair cuts over the internet.

    I want to thank Bobpaul and Bubbakat for all they do on here. Without them, many of us would be stuck in the middle of a lake yelling :0a35:
     
  12. Matt Smith

    Matt Smith New Member

    Messages:
    119
    State:
    Tennessee
    Well, I tinkered with it today. Pulled the pickup tube out and saw rust. Went out and bought a new plastic tank, bulb, and filter. Also picked up a carb kit.

    Got home and replaced everything but the carb kit. Pumped the bulb, but it never got firm, so I pulled the cowling. Evidently, the fuel pump gasket has sprung a leak.

    Guess I'll replace that tomorrow!
     
  13. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Matt if it had rust in it then it most likely cut a hole in the fuel pump diaphragm. But that is even better then rebuilding a carb. If you have the kit I would go ahead and soak that carb and do it to.
     
  14. Matt Smith

    Matt Smith New Member

    Messages:
    119
    State:
    Tennessee
    Got 'er done I do believe! There was a crack in the fuel line right before the fuel pump. When I would squeeze the primer bulb, fuel would spray from there. I thought it was coming from the pump itself, but when I removed the hose clamp, I saw the crack. Anyhow, I cut the line back about 3/4 of an inch and put everything back together. Ran like a top.

    I'll get a new line put in between the fuel pump and the connecter before I go to the lake. I also replaced the primer bulb, installed an inline fuel filter, and bought a new gas tank. Rebuilt the carb as well, but it didn't need it. Oh well. At least I can fish now!
     
  15. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Good deal Matt. Thats the way to get it done. Thanks for letting us know what cured your problem. It might help some one else with a similar problem.
    Now go fish and enjoy that motors running ability.:thumbsup:
     
  16. catseeman

    catseeman New Member

    Messages:
    1,189
    State:
    Indianapolis, Indiana
    Ichanged my fuel hose2 yrs ago with new ones and had trouble about 2months later. the new gas formulas eat the hose and gummed up the carb. went back to the 20 yr. old hose and nomore problems. goodluck. I run a 1966 40 hp bigtwin evinrude.
     
  17. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    I'm gonna have to start asking if you guys did the first thing you should do instead of assuming you did.

    Did you do a good visual check? That means take off the cowling and look.:p

    Congradulations Matt, I hope she runs good the rest of the yr.