Announcement

Collapse
No announcement yet.

Basic fuel system troubleshooting

Collapse
This is a sticky topic.
X
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Basic fuel system troubleshooting

    After getting bit in the butt once again by todays junk fuel hoses I thought I would post up a good procedure to trouble shoot your outboard fuel system.

    1 remove the fuel hose at the fuel pump. put hose end into clear clean container.

    2 squeeze ball and observe flow into the container...You may have to use your thumb on the hose end to help with priming bulb...A good bulb will self prime though...

    3 Fuel should GUSH into the container with each pump, and fill itself back up fairly quickly with each squeeze of the ball. If its not gushing in, I meen really flowing, you have a restriction in your fuel line. Most of the time its the inner vapor barrier that has collapsed and is restricting flow.

    4 Now look at the bottom of the container your pumping into. Does it have any cloudy or clear color to it?? clear is water and cloudy is ethanol/water mix.

    5 if the ball is slow to fill on each pump, you have a restriction between the ball and the tank. This could be racor filter, hoses or the pickup tube or the pickup tube check ball valve.

    7 Depending on your particular outboard, you also may need to check the output of the fuel pump, and the high pressure fuel pump output. This can be done with an automotive style fuel injection pressure gauge. Available at some auto parts stores as a loaner tool..

    I am sure I forgot a lot of the detail...and we have some really good wrenches here on the board...so if you would please add to this list, and I will make it a sticky for others benefits...
    [br]1994 Mako 215 Dual console Optimax 225[br]1978 Mako 19 with 90hp johnson[br]1996 Mako 22[br]1982 Mako 171 Angler 135 Black Max Mercury[br]1987 21b 225 Yamaha[br]1974 23 inboard Gusto gone.[br]1979m21 225johnson \"blue dolphin\" bought off this board and restored [br]with everyone\'s help!!Gone but not Forgotten....[br]1979 20 Mako 115 Suzuki gone[br]1977 19 Mako 115 Johnson gone[br]1976 23 Mako twin 140 Johnsons gone[br]1983 224 with closed transom and bracket[br]And 162 SOB (some other boats)[br]Venice Florida, Traverse city Mi.

  • #2
    Great write-up Dave, but I want to see you posting pics of fish and relaxing at sandbars (intentionally grounded) now that you're retired []
    [br]Michael R. Delgado[br]1972 Mako 22[br]http://classicmako.com/forum/topic.asp?TOPIC_ID=15745[br]1976 Mako 25[br]http://classicmako.com/forum/topic.asp?TOPIC_ID=18013&SearchTerms=mako,25[br]

    Comment


    • #3
      I'm listening, potential fuel problems here, any detail on Mercury fuel systems? Thanks in advance.

      BWP
      [br]Starcraft Bluewater 180, 1988[br]1996 Mercury 115 2+2 exlpto[br]Project Link: http://www.classicmako.com/forum/topic.asp?TOPIC_ID=46572

      Comment


      • #4
        use the tips in my write up to determine if your delivering good fuel to your engine...If you are, then take the next steps to determine if your getting the proper fuel you need to run.

        If pulsing your choke momentarily helps with the problem then you have dirty carbs. If it does not help, you may still have dirty carbs but likely a fuel pump or restriction in the hoses under the under the cowling.

        Clean your carbs...check or replace your fuel pump. and remember you particular engine does not use all 4 cylinders to idle with.
        [br]1994 Mako 215 Dual console Optimax 225[br]1978 Mako 19 with 90hp johnson[br]1996 Mako 22[br]1982 Mako 171 Angler 135 Black Max Mercury[br]1987 21b 225 Yamaha[br]1974 23 inboard Gusto gone.[br]1979m21 225johnson \"blue dolphin\" bought off this board and restored [br]with everyone\'s help!!Gone but not Forgotten....[br]1979 20 Mako 115 Suzuki gone[br]1977 19 Mako 115 Johnson gone[br]1976 23 Mako twin 140 Johnsons gone[br]1983 224 with closed transom and bracket[br]And 162 SOB (some other boats)[br]Venice Florida, Traverse city Mi.

        Comment


        • #5
          Very good Dave, that is correct, i'm still not certain it's the carbs or coil yet. I have much to learn! Just plain thanks!

          BWP
          [br]Starcraft Bluewater 180, 1988[br]1996 Mercury 115 2+2 exlpto[br]Project Link: http://www.classicmako.com/forum/topic.asp?TOPIC_ID=46572

          Comment


          • #6
            I'm almost positive I have a fuel line issue

            the tank and lines were installed in 2009.

            used some ethanol in the beginning for 3-4 years

            now that the good non-ethanol is easily attainable I only use it.

            swapped my engine from a 94 200 yami to a 99 fuel injected one

            just started having issues 6 months ago.

            narrowed it down to fuel supply line.

            What is the best under deck line to replace what I have with.
            1977 Mako 21 200 yamaha[br]PSL Fl[br]

            Comment


            • #7
              Please contact me Michigan Dave. [email protected]
              lou cabot

              Comment


              • #8
                Hello All-just purchased a 2005 Mako 172 with a Suzuki 115 -4 stroke, has major problem getting up to speed. Starts and idles just fine but can not take throttle. Fuel filter separator reveals water in fuel. I am paying a shop to diagnose and pump out old fuel(sat for a year unused by former owner) and hopefully will solve problem. Have read a lot about problems caused by steel engine holder plug causing severe corrosion in aluminum casting allowing exhaust gas to leak. I have ordered via Amazon an aluminum replacement plug. Has anyone replaced this plug and how hard can it be to remove original?

                Comment

                Working...
                X