Announcement

Collapse
No announcement yet.

Hesitation at low rpm throttle up

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Hesitation at low rpm throttle up

    I recently acquired a hesitation when accelerating from low rpm on my pontoon. The motor is a 2004 Yamaha 50TLRC. If I throttle up quickly or slowly does not always matter, the motor will stumble more or less then come up to running speed and run like it was new. It idles fine and starts fine. Yesterday we ran for about 2 hours WOT almost non-stop without issue until slowing and trying to throttle up. I changed the fuel line, fuel filter and spark plugs with no affect. Does anyone have an idea of what could be the cause? There is a diaphragm in the carburetors that I assume is an accelerator pump. If not functioning correctly could that be the culprit?
    Robert
    A ship is safe in harbor, but that is not what ships are for.

  • #2
    Let me know what you find out. My toon is doing the same thing. Last season when I'd give it a lot of throttle from stop or going slow it would take right off and quickly be on plain. It would even put you back in your seat a little, as much as a 50hp 2 stroke can on a 20 foot toon that is. But now when you throttle it up from stop or going slow (about no wake speed) it bogs down and i have to let of the throttle. Now if I gradually throttle (very gradually) it up till its on plain its fine and I can run it WOT all day long. The motor idles and starts fine as well.

    Comment


    • #3
      run some sea foam throw it thinking it was a clog of dirty carburetors or fuel line with no affect. My next thing to try was going to be spark plugs. My top end speed seems to be a tad slower too, just a tad though.

      Comment


      • #4
        That sounds a lot like what I am experiencing, Gregory. I'm going to pull the float chambers and look for trash. The fuel filter was very clean so I'm not sure I'll find much in the chamber.
        Robert
        A ship is safe in harbor, but that is not what ships are for.

        Comment


        • #5
          I did notice some debris in the gas tank, too big to get sucked through the screen on the fuel hose. But could temporarily block it though with the right amount of sudden suction a guess?

          Comment


          • #6
            Time has been short lately but I finally figured out how to fix my carburetor problems. I had taken the float bowls off and they were spotless. I even changed that diaphragm that I spoke of earlier too but to no avail.

            What finally worked:

            Drop the boat off at a place that says they are a certified Yamaha dealer. Pick it up a week or so later and write a fat check to the people. Presto! The old motor runs great. So good that the prop spun that rubber bushing in the hub when I tested it a week ago. I found some dings in the prop that I don't remember. Who knows where they came from. New bushing installed last week and I ran around hard half the day this past Sunday with no issues. I even fished 4 jugs while I ran the boat and picked up a 13.5 lb. blue cat. The world is again spinning in greased grooves.
            Robert
            A ship is safe in harbor, but that is not what ships are for.

            Comment


            • #7
              Congrats on getting the outboard running smooth again. The older I get the dumber I get so I pretty much have to take everything right to a mechanic.

              Comment


              • #8
                Glad you got it running again and were able to wet a few hooks.
                Good judgement is a result of experience. Experience is usually a result of bad judgement.

                Comment

                Working...
                X