• If this is your first visit to the iboats.com Boating Forums, be sure to check out the FAQ. To post a question or comment, begin by signing up. To start viewing messages, select the forum that you want to visit from the selection below.


Announcement

Announcement Module
Collapse

Help Tip: If you have a question that has not been answered to your satisfaction in the archives, it is always best to start a new thread of your own. By starting your own thread, you will receive the maximum number of views by forum members.

Below are some additional forum policies in hopes of all iboats members will follow, Thank you.

1. Please do not reply to old topics or hijack existing topics. Old topics of a technical nature are like a library book, Please do not write in them.

2. Old topics should be considered archives and used for reference only. Please do not reply to them.

3. Do not take over someone elseís topic (aka hijack) with your own question, even if it is similar. If you have a question that has not been covered to your satisfaction in the archives, it is always best to start a new topic of your own.

4. If you have a question for the original poster (OP) and the topic is over 30 days old, send the OP a PM, he may not even visit the forums any longer, or may not notice your question in the old topic.

5. By starting your own topic, you will receive the maximum number of views by forum helpers that may not even notice your question when itís posted at the end of someone elseís topic. And those answers will be specific to your particular issue.

6. Please do not post to topics that have been inactive for more than 3 months unless you are the original poster. We have very active forums and any topic that remains inactive for that long should be considered "dead". It is especially confusing when there is an entirely new question posted to an old topic.

7. Posting at the end of any topic is considered to be hijacking the original posters topic which in turn subjects the topic to be closed if it continues to happen thus not making it fair to the original poster in the future had for some reason he/she needed to return for additional information or provide an update of the problem solved which is always welcomed within a reasonable amount of time frame.

8. Please note that you should see a red banner pop up near the bottom of each inactive topic asking you not to reply to old topics. The Red banner will read: Please note this topic has been inactive for 90 days. For the best results, please start a new topic.

Thank you all in advance for doing your part in helping iboats run a smooth ship.

Additional forum rules linked below.
http://forums.iboats.com/forum-rules-guidelines-405/
See more
See less

DT 55 Fuel Pump or Air Leak or Both

Page Title Module
Move Remove Collapse
X
Conversation Detail Module
Collapse
  • Filter
  • Time
  • Show
Clear All
new posts


  • DT 55 Fuel Pump or Air Leak or Both

    Hi; I have a 1987 DT 55 2 stroke triple, old but reliable. Starts fairly well, idles well enough for the year, runs okay at wide open throttle, issue appears at mid throttle say 1/2 -3/4 open, motor surges (speeds up then slows down) it feels like either air or fuel starvation. pretty cyclic in nature. In the garbage can with the muff on doesn't due it with the fast idle seems to be when under load.

    I have tried to adjust the carb pilot air scres but doesn't smooth it out, might lessen the effect but still there. I have replaced the primer bulb, no viable cracks or kinks in the air lines, vents on tanks are open (been caught on that recently) I still have to check the pickup line inside the tank and needle valve on tank for leaks.

    Question; Can this be an indicaiton of the fuel pump diaphram wearing out? I have also replaced the fuel filter.


  • #2
    Re: DT 55 Fuel Pump or Air Leak or Both

    Time for a proper carb clean ....
    __________________________
    ... THE MAXIMUM HORSEPOWER IS NEVER ENOUGH ...

    Comment



    • #3
      Re: DT 55 Fuel Pump or Air Leak or Both

      Originally posted by deejaycee_2000 View Post
      Time for a proper carb clean ....
      Carbs have been completely rebuilt (thanks to Ethanol) only run Octane 91 or 94 with Marine Stabol in there.

      Comment



      • #4
        Re: DT 55 Fuel Pump or Air Leak or Both

        In that case I would replace the fuel pump diaphram ....
        __________________________
        ... THE MAXIMUM HORSEPOWER IS NEVER ENOUGH ...

        Comment



        • #5
          Re: DT 55 Fuel Pump or Air Leak or Both

          http://forums.iboats.com/engine-freq...em-283363.html
          this shows how to test fuel system, and using the clear tubing for testing will show if it is sucking air.
          I have seen cracked pick up tubes before in the plastic fuel tanks, but any connection on suction side of pump can be a source for air

          Comment



          • #6
            Re: DT 55 Fuel Pump or Air Leak or Both

            Originally posted by 99yam40 View Post
            http://forums.iboats.com/engine-freq...em-283363.html
            this shows how to test fuel system, and using the clear tubing for testing will show if it is sucking air.
            I have seen cracked pick up tubes before in the plastic fuel tanks, but any connection on suction side of pump can be a source for air
            Thanks all, good sage advice, good forum!

            I was planning on rebuilding the fuel pump since it is pretty inexpensive for the parts and simple to do, plus I have no idea when service was last done on this part if ever.

            I will definitely be walking the system for air leaks (I'll start with the clear tube method first) , I suspect one of my tanks when <1/2 full as the major issue, however running from the other tank I never completely got rid of the issue hence the fuel pump plus sometimes it is a little hard to start (starts but then dies off after a couple of seconds) re-prime required to catch.

            Engine is definitely wanting either more air or gas or combo of both, but pretty solid overall,

            It gets used very hard with all the teenage kids and towing etc.

            Comment

            Working...
            X