Recent content by zoomzoom1970

  1. Z

    Compression Check...

    Could someone tell me what the compression rating is on a 1999 100HP Yamaha 4 stroke?
  2. Z

    testing a coil

    I have a 1999 100hp 4-stroke Yamaha . 2 bottom cylinders spark plugs are not burning clean and engine will bearly stay running. Already rebuilt carbs no change I am almost positive it is a coil pack it has 2 coil packs 1 for top 2 cylinders and 1 for bottom 2 cylinders. But before I spend the...
  3. Z

    1999 yamaha 100 four won't idle?

    Cleaned all 4 carbs still running the same. Top 2 spark plugs look really gas fouled, could it be the coil for the top 2 cylinders?
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