NS - too much fuel:oil?

Discussion in '2-Stroke Engines' started by velzie, Sep 12, 2014.

  1. velzie

    velzie Member

    The bike ran one day, then on the following day - no start. There is spark, compression and fuel. I believe there is too much fuel being dumped into the combustion chamber causing the no-start. See attached pictures.

    My carb is clean - no debris around my float needle/seat. The float does not have cracks. The carb itself is not leaking. Flushed out gas and replaced with fresh 25:1. The engine turns and chugs but there is no combustion. The NGK B6HS plug sparks out of the chamber and all electrical contacts have been checked and reattached. Gas is visible on the plug along with it's smell after attempts to start.

    Although there may not be spark under compression, the colour of the combustion chamber suggests to me that there is too much mix or oil, causing the no-start. I am off to check that the exhaust is not clogged.

    Wondered if any of the more seasoned MBer's had some advice.

    20140909_184515.jpg 20140909_184658.jpg 20140909_184705.jpg

  2. velzie

    velzie Member

    So I now believe that water got into the combustion chamber and crank case. I am going to search for recommendations, but it seems like now is a good time for a little over-haul.

  3. crassius

    crassius Well-Known Member

    25:1 should fire OK, water can be blown out well enough to get it to start by pedaling a lot with the plug out, I'd guess bad plug or low compression