won't stay running

Discussion in 'Boats and Motors' started by street guy, Jul 20, 2008.

  1. I have a 9.9 johnson. It starts and runs fine but stalls after about 20-30 sec. It will start right back up. It will run with the choke on but not at an idle. IT always ran good before. I was wondering if I have the fuel mixed to rich. I mixed it 50:1 like the book says. But may have mixed it a little richer the last time because I got in a hurry and couldnt find the measuring cup. It does smoke a little.
  2. It probably needs the carb rebuilt.

  3. Lewis


    Is the vent open on the fuel tank?
    Could be carb,fuel pump or primer bulb.
    Does the primer bulb remain firm?
  4. check out all lewis/s advice . and also is the arrow on the prime bulb pointing towards the motor . gotta be some thing easy . all fitings are tight ,could be sucking air.
  5. EE


    This worked for another member not long ago, so I'll throw my suggestion into the mix again.
    What catches my attention is that it works with the choke on, but stalls when idling.
    You may need to simply adjust the idle. This also happened to my 9.9, I adjusted the idle (by about a quarter turn) and that solved the problem.
    worth trying before spending big bucks.
  6. I brought the boat home from were I store it at my brothers.Told the wife I was going to put it in the yard she thought I was going to sell it. Well anyway I checked everthing Found nothing that looked bad or lose. The vent on the tank was open. opened it more just for good measuers. Put the ear muffs on the intakes .It fired right up kept running. I closed the vent on the tank .let it run awhile it never missed a beat. PLayed with the throtle up and down. started and stoped several times. It ran good. Think I might try turing the ideal up a little. Thanks everone.


    so i take it you have never had this motor in the water before until now? or have you had this problem all along?
  8. I had simalar problem. I just let it warm up good and it runs fine. This time it never came out of it. It's been running okay now Haven't had it back in the water yet. Will do that thursday.
  9. Just had my 81 25hp doing the same. These are the steps I took, after making sure the gas was good and flowing properly,
    removed the plugs and cleaned them (ended up buying new ones)
    Checked the spark,
    checked compression
    removed carb - took apart and blew air all over and replaced.
    Once it was all back together I pulled the rope 3Xs with the choke in, then opened the choke and started the engine. It ran like a champ after all that.

    You never put the year of the engine, or typr of gas tank is used. You may want to check or loosen the cap too.