Sick Six

Discussion in 'Bubba's Outboards' started by odtimr, Sep 2, 2009.

  1. odtimr

    odtimr New Member

    Messages:
    206
    State:
    nebraska
    I have problems with my 1986 mercury 6hp serial A0963511. Hard to describe the problem, it starts great, idles a little on the high side, but starts popping after just a few seconds. It like I said makes a pretty loud pop noise, every few seconds (4-10) and seems to slow down, like its shuts off but right away runs again, every time it pops it blows a stream of smoke out the exhaust. I am afraid to take it out on the lake, or rev it up in the barrel. I had to put a stator on the first of last year and two years before that also, it ran ok after that, but haven’t used it much. Been catfishing from the bank mostly. If I had this problem on a car I would be looking at the ignition, but where on a boat motor?
    The compression is 90# in both cylinders, but tester is suspect, as I had a bad bottom valve stem and only the one I could get to work was the stem in the release valve. Evidently they take a special valve stem for compression testers. I checked the timing and it is about 2 degrees advanced from the 6 degrees recommended at idle, the idling would not slow enough to put the mark on the 6 degrees. Appears to me you can’t really change the timing anyway, factory set? Carburetor was serviced 4 years ago, but they did a lousy job. Brought it back and wouldn’t start. I found they lost and didn’t replace the spring under the choke primer. I just looked at the carb. and blew it out, it was very clean. I did put it together without new gaskets, only putting vaseline on them. This was yesterday after the problem had started. I sure can’t figure how to check the float height, and the (new) plugs seem to be pretty wet. The gas is new, and correct mix. I have changed the tanks and have a new hose assembly. With a clear hose I was getting quite a lot of bubbles in the gas line, so hooked direct from the gas tank to the carburetor bypassing the fittings and the fuel filter. No improvement in the popping. Any suggestions will be appreciated. I am afraid this year, because of health reasons, will be the last year I will be able to go boating by myself and sure want to get it back in if I can. Thank you.
    Luck
     
  2. odtimr

    odtimr New Member

    Messages:
    206
    State:
    nebraska
    Forgot to mention in my post I have a spark tester and it seems like I have a very good spark to both plugs all of the time. Thanks again
    Luck