85' Merc 25XD needle setting question!

Discussion in 'Bubba's Outboards' started by BoxxerBoyDrew, May 7, 2008.

  1. BoxxerBoyDrew

    BoxxerBoyDrew New Member

    Messages:
    143
    State:
    Woodway, Texas
    Hey Fellas,

    I have a question on the setting of the "Low Speed Needle" on my 1985 Merc 25XD with a walbro carb. The Seloc book says to set the needle at 1&1/4 turns from barley snug bottom, but when I try to get the motor to Idle on the muffs in the Driveway it wont even try to run at that setting. I can pull the choke knob to Full or half and it will BARLEY Idle if I keep on pushing the electric key choke in every few seconds. So I richened the needle up about 3/4 of a turn, and it will idle around 700-800 RPM's OK. BUT when I get to the lake and I let it warm up at this setting, and then try to get the boat up on plane it acts like it is loaded up and will only run about 3000 rpm. So I will throttle it back to a little over 1200rpm and run it like that for 5-10 min, and it all of a sudden will throttle up like the carbs have cleaned them selves out! ???????? I did a search of this forum and found some instructions you gave for a 40hp merc, and I read where you were saying to adjust everything while in forward gear. I also read basically the same instructions in the book, but if I can't get it to run/start with the book setting of 1&1/4 turns out from bottom, then how am I supposed to set it while in forward??? I know this may be a dumb question, but I have never had to adjust a outboard before, but have worked on MANY 2 Cycle lawn mowers, weed eaters, chainsaws, and R/C Nitro motors, so I am kind of lost here!

    I rebuilt the carb, and got the settings set to the book specs on the float, and everything else, but I am unsure on where to go from here! AS it sits now the low speed needle is set just a hair under flush with the carb body, and with muffs it will Idle at 800rpms in the driveway as long as I want it to. When I check the plugs after it idles to where it is warmed up, they are wet! Not dripping wet, but still they are wet like it is WAY RICH!!

    I tried to get all the info for you, but if you need more I will do my best!!!

    THANKYOU in advance for any help!!!:embarassed:
    Andy
     
  2. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    what kind of shape is that needle point . Is it rounded off or sharp on the end.
    Do you have two needles or one to set. Setting it in the drive way on the muffs will get you no where those have to be set with the lower unit under water under pressure and in gear at idle.. Then you set the high speed unless it has the fixed high speed jet and if it has and this is a new to you motor then we need to check the jet to see if some one has changed it.
     

  3. BoxxerBoyDrew

    BoxxerBoyDrew New Member

    Messages:
    143
    State:
    Woodway, Texas
    Bubbakat,

    The motor is a "New to Me" as I have had it about a Year, but most of the time it has been sitting in the garage while we were rebuilding the boat. I ran it about 10 times last year, and it did about the same thing, and that is why I rebuilt it. It did have a bad seal around the priming "button" where the choke lever pushes it down when pulled out to full choke, so I did a complete rebuild of the carb. The only parts I DIDN'T redo in the carb were the VERY SMALL brass "orifices" that I have never dealt with. So the low speed needle is from the rebuild kit, so I am assuming that it is pointed. I really don't remember looking to close at it. As for the high speed setting it is "fixed" so I didn't mess with it other than to cleaning it while cleaning the rest of the carb. There is only 1 lowspeed needle to set and the high in fixed.

    So my MAIN PROBLEM is I am trying to set it in the WRONG settings, and i HAVE to be in the water in gear to get it set right. CORRECT??? Can I do it with the boat on the trailer, or do I need to be floating out in the water?? The reason I am asking is I don't have anyone to "drive" the boat while making changes to the carb till the weekend, when my son can do the steering while I get it setup.

    Should I pull the low speed needle to see what shape the tip is in? Also what would I need to look for in the high speed needle? When it is running fine I can easily get on plane, and it is running 5600rpm, and the book says it should be between 5000-6000rpm at WOT. So I am thinking the high speed setting is fine, and I just need to get on the water to get it setup on the low side.???

    THANKYOU SOOOOO MUCH for the help!!! This site ROCKS!!!!:cool2: It is just the book is a little vague in some areas on how to get things set correctly!

    Thanks Again,
    Andy:big_smile:
     
  4. BoxxerBoyDrew

    BoxxerBoyDrew New Member

    Messages:
    143
    State:
    Woodway, Texas
    Also is there a place to add a Temp guage on this motor?? Or where can I check for the info to see if there is a spot for a temp guage? Merc??


    Thanks,
    Andy
     
  5. BoxxerBoyDrew

    BoxxerBoyDrew New Member

    Messages:
    143
    State:
    Woodway, Texas
    Bubbakat,


    Can I adjust the settings when the boat is on the trailerbacked down on the ramp in the water? What dhould I be looking for on the High Speed Needle? And last of all how hot should the water be out of the Tattle Tale Stream?



    Thanks for the help!
    Andy:wink:
     
  6. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Yes you can leave it on the trailer just be sure to strap it down good. As for the heat , you need to be able to lay your hand on the top of the head and feel the heat but not so hot you can't leave it there for a few seconds. Feel the water it should be warm to the touch but not scalding hot.
     
  7. BoxxerBoyDrew

    BoxxerBoyDrew New Member

    Messages:
    143
    State:
    Woodway, Texas
    COOL DEAL!!

    We took it to the lake yesterday, and I followed your instructions, but I couldn't get the motor to run unless the Low needle was about 2 turns out!!! :crazy: So I got my son to drive while it was idling along, and I think I got it set pretty close! The head was warm to the touch but NOT HOT, and the water was warm but again not hot at all!:big_smile:


    I can't get the idle down to 700-800 RPM like the book says it should be at Idle in forward though!!:embarassed: It will go to about 900rpm, but then it just stalls out! Do you think it could be the float? I am going to pull the Low Needle today, and I will get you a pic and post it!

    As it stands right now on the boat it is at a fast idle at about 1000rpm, and it will take off and plane at NO PROBLEM, NO BOGGING DOWN AT ALL! BUT at that high of rpm it is going pretty fast, and makes it a little HAIRY going to the boat docks!!!:eek:oooh:

    Holler back if you think I should check the float level, or if that could be causing the problem!


    THANK YOU AGAIN!!!!!
    Andy
     
  8. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Do a syn and link. There should be a idle screw that will let you back the idle down without moving the set screw in the carb.
     
  9. BoxxerBoyDrew

    BoxxerBoyDrew New Member

    Messages:
    143
    State:
    Woodway, Texas
    Bubbakat,

    I don't understand what you are talking about when you say " Do a syn and link" ? There is a Idle screw I have been trying to adjust at the same time I am setting the needle to get the motor the Idle around 800rpm in forward at Idle speed. I will get it around the correct Idle, but then it will Idle at 800-900rpm, and then after a minute or so it slows and dies! :embarassed:



    I will do my BEST to get the carb pulled off tonight, so I can check the float, and I will get a pic of the low speed needle first!

    This last weekend we took it out Sat and Sunday, and it ran OK, except when I first start it it will act like it has loaded up for a few minuets and then will do OK for the rest of the day! So I am getting close, but I still think it is a little rich, and that is causing the loading up at a cold start! I am thinking that the float is allowing too much fuel when I am PRIMING the carb at cold starts, and that might be my problem!???????

    So THANKYOU for your HELP AND PATIENTS WITH ME AS WELL!!!!

    I will get you a pic asap!!!!
    Andy