Merc 25XD Problem / ???

Discussion in 'Bubba's Outboards' started by BoxxerBoyDrew, Apr 23, 2008.

  1. BoxxerBoyDrew

    BoxxerBoyDrew New Member

    Messages:
    143
    State:
    Woodway, Texas
    :wink:Hey Everyone!,

    I am having some trouble with my 1985 Merc 25XD. I made the cardinal mistake of working on the motor, and changing the setup at the same time, and now I am unsure of where the problem is coming from!

    Here is what I did. While finishing up the rebuild of the 85 Bass Tracker I bought last year I installed a new water pump impeller, and replaced the old dinged up prop, and rebuilt the carb too. Everything went without too much hassle, but NOW it seems like the motor is loosing it's "bite" in the water when around 2/3 throttle. It will be running and pushing the boat up an plane well, then it seems to lag for a QUICK SECOND and it seems to not want to drive the boat on plane well!:confused2:

    I put a carb kit in the carb, and it now starts VERY WELL, and Idles well too! the water pump impeller swap went OK, but the book was unclear on where to unhook to shift rod so you can drop the lower unit, and I took off the linkage arm on the left side ( if looking at the front of the motor) that links with a metal rod to the remote lever, and then I figured out where you are supposed to unhook the shift rod!!!:embarassed::eek:oooh: So I put the "arm" back to where the rod allowed it to be put back on the splined rod, that seems to be OK.???Well it turned out to have a perfectly good impeller, so I did all of the work for NO REASON!!!:confused2:

    So the other day before going out on it's first trip with it's new carpet, console, and all the other stuff we did, I installed the new prop. It is a COMP-Pro Composite prop, and is 4blade, 10" Dia and a 13 deg pitch. After finally finding the props part # off of the original ( too Me) prop, I looked it up and found it be a 10 3/8" x 11 deg prop.

    So I am wondering weather it is the prop "Slipping" in the water and loosing it's bite, or if the shift link arm is 1 spline out of adjustment and it is causing the lower unit to be slipping out of gear under a load, or what????????????:eek:oooh:

    Also at WOT it is only running at barley 5,000 RPM's. I am unsure of what the RPM's were before, as I didn't have one installed on the boat before the remodel. The book says the motor should run between 5,000 -6,000RPM.

    PLEASE HELP, if possible?????:confused2:
    Andy

    P.S. Sorry about the long post!!
     
  2. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Where do we start here. I would try the old prop to see if that would take care of the prop slip and go from there. I never have liked a 4 blade prop and composit ones are even less on my list. They flex way to much inmy book. I like to take a prop and have it cupped to get the bite I want.
     

  3. BoxxerBoyDrew

    BoxxerBoyDrew New Member

    Messages:
    143
    State:
    Woodway, Texas
    Bubbacat,

    I was thinking of doing that, but when I was taking off the old prop I screwed up and put a small bend in the rearmost edge of the prop with the wrench I was using!!:embarassed::embarrassed_2::0a13: The wrench was resting on the prop hub nut as well as the nut holding the prop on and :beat_brick: !!!!! So I was unsure if it would hurt anything if I tried it! I WAS HAVING A BAD DAY !!!! I will get you a pic and post it here in a few.

    THANKYOU FOR THE HELP!!!
    Andy
     
  4. BoxxerBoyDrew

    BoxxerBoyDrew New Member

    Messages:
    143
    State:
    Woodway, Texas
    Bubbacat,

    Here are a few pics of the prop. I also talked to a buddy of mine, and he said I can remove the dig pretty easy with hand tools. He said it won't be exactly 100% perfect, but it will be ok to see if it is the prop causing the problem. So I took my body working tools and I was able to get the ding out! It is pretty much back to the way it was. I used a slapspon and a hand dolly and got it back to 99%. SO I will put the old prop back on and see what happens. :eek:oooh: There were also a few burs on the edges of the prop where I got into the bottom of the boat ramp last year when the lake was 10'+ low, so I knocked them down with a hand file as well! I DIDN'T remove hardly any metal at all, just the SHARP edges that were about 3/4" in lenght on the outer edges of the blades.

    Let me know if this sounds OK. PLEASE!! I will include a pic of the prop before anyway.


    THANKS AGAIN!!!!
    Andy
     
  5. BoxxerBoyDrew

    BoxxerBoyDrew New Member

    Messages:
    143
    State:
    Woodway, Texas
  6. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    That ding on the inner circle wouldn't have interfered with it but the outer rough edges would have affected it somewhat. If you have the edges smoothed outsome waht the take a good file and dress them up a little smoother and slap that thing on and let us know the results.:wink: