Messin with a yammi Carb

Discussion in 'Outboard Maintenance' started by OSWLD, Feb 13, 2010.

  1. OSWLD

    OSWLD Don't Float the Mainstream

    i put a rebuild kit in my girlfriend's dad's 2002 9.9 yammi 4stroke. it would idle fine for a little bit then just die, then a very hard start. when it was in the water, it would start right up, idle, but then when you'd put it in gear and put a load on it it would die.

    so anywho, i put the kit in it, cleaned everything, and it still did it. well what as hiding under a plug was the pilot jet (#5 in this pic).

    i took it out, soaked it in carb cleaner, put it back in to the factory settings and that did it. thats all it needed the whole time. i've talked t a couple other people after the fact and they said thats usually where your problem lies. wish i woulda known. hopefully this helps someone.

  2. Flyline

    Flyline Won "Do More With Less" Award!

    My motor done exaclty the same thing after the carb rebuilt, new fuel pump, and spark plugs. My motor needs new coils because of weak spark on each cylinder.

    Check and see if u have a weak spark on the cylinder.

    U need bright blue spark from spark plug from the cylinder head about 1/4" gap from each other.

    If your sparks come out bright blue then it's might need new fuel alcohol free lines, bulb, and check for fuel pump.

    Just a thought.

  3. Frank_Sebastian

    Frank_Sebastian Well-Known Member

    That is an excellent post Oswald. The carb you mentioned is one of the more difficult to get right. I bought a heated ultra sound cleaner just for the 9.9 and 25 HP Yamahas. I learned a trick from a friend about the 25. He bores out the running jet a few thousands of an inch when all else fails. I know this works, but we think the factory has taken care of this in newer  carbs.

    Thanks and best regards,
  4. cal1320

    cal1320 Well-Known Member

    I've used the wifes ultrasonic jewelry cleaner to clean up mechanical fuel injection nozzles and carb jets/pieces. It works fantastic. Just use regular jewelry cleaner in it though. They tend to get all pissy when you use garage style chemicals in them.