Bogs down when I give it gas

Discussion in 'Bubba's Outboards' started by jeffw51, Sep 17, 2007.

  1. jeffw51

    jeffw51 New Member

    Messages:
    288
    State:
    mo
    my70 115 johnson bogs down when i give it the gas,comression great ,spark good.here is the funny part if i let off on the throttle then give it gas two or three times it will take off and run perfectly.as soon as i let off the gas it starts bogging again?fuel lines and fuel are new,new plugs.it will idle and run slow,but medium speeds bog down,runs perfect wide open.
     
  2. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    You could have a plug jumping fire from the boot to the head. Run it at night and look under that cowleing and take a look at it . Another thing you could have some bad fuel or some trash in one of the carbs. Next time you are out take the air silencer off the carbs and lay two fingers in the throat of the carbs one carb at a time and if it picks up the carb needs stripping and rebuilding.
    From the sound of it it is fuel related just have to figure out where and why.

    Look at your plugs and see if they are different color after running. If one is wet and oily and other dry and normal then the ewet one isn't getting the fire it needs.

    What type of plugs do you have in it.
     

  3. LittleRiverBigFish

    LittleRiverBigFish New Member

    Messages:
    35
    State:
    Iowa
    Bubba,

    If the plugs are wet and oily, what is the next plan of action?

    Last time I had my boat out, it was very reluctant to start (usually starts on 1-2 pulls). When I did get it started, it too would bog down when I gave it gas. If I let off the throttle it would come back to life and then run fine if I accelerated gradually. After reading this thread, I pulled the plugs last night and both were oily and wet.

    A friend of mine suggested that since my fuel line had been connected for a day or two outside that the expanding gases in the tank could have possibly forced fuel into the motor, essentially flooding it out. Thus the reason it was hard to start.

    Any thoughts? Is it time for new plugs?

    BTW, motor is an '88 Johnson 30 hp.
     
  4. AwShucks

    AwShucks New Member

    Messages:
    4,532
    State:
    Guthrie, Oklaho
    John, while waiting for Bubbakat to come around, it would be nice if you had him some compression readings on those cylinders. I am not the mechanic that Bubba is, but to me it is a carb issue... course I have been wrong before.
     
  5. catfish kenny

    catfish kenny New Member

    Messages:
    6,064
    State:
    Iowa
    I am not much of a machanic either but reacently I had a similar problem with bogging down...didnt pull a plug because I noticed my fuel lie ends were bad....replaced them and no problem.I am running 15hp johnson so maybe you'be lucky and be easy fix......Good Luck!
     
  6. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Had me cornfused here I thought we were on the 115 but reread the last post.

    When was the last time you tuned this engine up and replaced all the fuel lines. A good spark test and compression test is in order to.
    This will tell me how well your engine is.
     
  7. catrod

    catrod New Member

    Messages:
    157
    State:
    North Carolina
    Jeff I'm no boat motor mechanic, but used to be ASE certified and it sounds like your accelerator pump has a hole in it. A very easy and cheap fix, you may be able to fix yourself. Or you could shell out the bucks and have the carb rebuilt, by now after having problems it sounds like it may be time for it to be done. I used to have an older motor om my old boat and had the carb rebuilt every spring to prevent problems like this.
     
  8. AwShucks

    AwShucks New Member

    Messages:
    4,532
    State:
    Guthrie, Oklaho
    Willard, I think the original post was a 115 hp motor. Don't know if the motor range changed or if it was a typo.
     
  9. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill


    Rod 2 stroke motors don't have accelerator pumps. And technically they don't have carbs either because of that. They have what is referred to as a carb but really is a fuel metering device because it doesn't have the accelerator pump.:big_smile:

    Guys always remember when trying to find out what is wrong you need two things right off the starting line. You need a spark test and a compression test.
     
  10. Coloman

    Coloman New Member

    Messages:
    441
    State:
    Soddy Daisy, Tn
    Wiilard you have a pm.
     
  11. LittleRiverBigFish

    LittleRiverBigFish New Member

    Messages:
    35
    State:
    Iowa
    Sorry to create confusion and hijack the thread. I'll start a new one based on my questions...:embarassed: