Page 1 of 2 12 LastLast
Results 1 to 20 of 21
  1. #1
    Member mikesjet's Avatar
    Join Date
    Aug 2009
    Location
    Shippensburg
    Posts
    814

    What lower unit do I have?

    merc 250EFI OT971386.

    I have broken something inside it but don't really know what. It will engage in gear and stop the prop, but zero forward or reverse movement. I have it out, just curious what lower I have, I don't think these motors had torque masters or anything like that.

  2. Major Flagelator Gamblinman's Avatar
    Join Date
    Jun 2004
    Location
    Yantis, TX
    Posts
    4,121
    #2
    Based on your serial number, Mercury says it originally came with a Torquemaster. Your mechanic can verify. Unless you have the proper tools, I wouldn't recommend trying to rebuild it yourself.
    "Better to remain silent and be thought a fool than to speak out and remove all doubt."

  3. Member mikesjet's Avatar
    Join Date
    Aug 2009
    Location
    Shippensburg
    Posts
    814
    #3
    I don't plan on rebuilding it myself, I am just curious as to what it is.

  4. Member
    Join Date
    Dec 2011
    Location
    Huntingtown, MD
    Posts
    2,564
    #4
    TM with 2 piece driveshaft and small propshaft
    04 521VX 250 Pro XS
    14 521C 250 Pro XS

  5. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
    Join Date
    Apr 2008
    Location
    Greenville, SC (US)
    Posts
    94,945
    #5
    Quote Originally Posted by bass.man65 View Post
    TM with 2 piece driveshaft and small propshaft
    +1... A Gen-1 TM.


    Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
    Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
    Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor

  6. Member
    Join Date
    Oct 2013
    Location
    NC
    Posts
    132
    #6
    That’s the toughest engine I’ve ever owned

  7. Member mikesjet's Avatar
    Join Date
    Aug 2009
    Location
    Shippensburg
    Posts
    814
    #7
    Update: got the prognosis from shop. Pinion gear broke and took the forward and reverse gears with it. It was an SEI unit, didn't know that when I bought the boat, but will replace with another. I didn't know it was an aftermarket and it performed perfectly until the circumstances that I think would have done in any lower.

    New question, what gear ratio would it be? I see SEI has listed a 1.65-1 and 1.75-1. I have a 26p Trophy Plus and it works flawless if that helps.

  8. Member
    Join Date
    Aug 2016
    Location
    Colbert co. Alabama
    Posts
    3,441
    #8
    Well there is the problem, SEI. I have heard SEI does not recommend their LU on a 250. Do a search here on SEI lowers.

  9. Member mikesjet's Avatar
    Join Date
    Aug 2009
    Location
    Shippensburg
    Posts
    814
    #9
    It had one on it when I bought it. My mechanic said to just get another.

  10. Member Bob G.'s Avatar
    Join Date
    Jan 2013
    Location
    Milton, Vermont
    Posts
    6,087
    #10
    I'd pony up for a Mercury lower unit.
    2006 Triton TR-21 XD, Mercury 225 Pro XS, S/N 1B287870

  11. Member
    Join Date
    Aug 2016
    Location
    Colbert co. Alabama
    Posts
    3,441
    #11
    Quote Originally Posted by mikesjet View Post
    Update: got the prognosis from shop. Pinion gear broke and took the forward and reverse gears with it. It was an SEI unit, didn't know that when I bought the boat, but will replace with another. I didn't know it was an aftermarket and it performed perfectly until the "circumstances" that I think would have done in any lower.

    New question, what gear ratio would it be? I see SEI has listed a 1.65-1 and 1.75-1. I have a 26p Trophy Plus and it works flawless if that helps.
    What circumstances do you mean? Before spending more money I strongly suggest you do some research on BBC.

  12. Member
    Join Date
    Jul 2004
    Location
    Penn PA
    Posts
    15,104
    #12
    Quote Originally Posted by mikesjet View Post
    It had one on it when I bought it. My mechanic said to just get another.
    Your mechanic is giving you terrible advice, get a Mercury lower unit.



  13. Member
    Join Date
    Dec 2011
    Location
    Huntingtown, MD
    Posts
    2,564
    #13
    A SEI unit will work if your in a bind but you will be on borrowed time on a pro xs.
    04 521VX 250 Pro XS
    14 521C 250 Pro XS

  14. Member mikesjet's Avatar
    Join Date
    Aug 2009
    Location
    Shippensburg
    Posts
    814
    #14
    I do not have a pro XS

  15. Member
    Join Date
    Aug 2016
    Location
    Colbert co. Alabama
    Posts
    3,441
    #15
    Not the model, it is the horse power. Frankly it is pretty well accepted that SEI is Chinese junk. There is a reason they are so cheap. I know the Mercury is obscenely expensive. Might look around for a good used one.
    Last edited by gehol; 08-28-2019 at 04:16 PM.

  16. Member
    Join Date
    May 2011
    Location
    Spangle, WA
    Posts
    6,180
    #16
    Quote Originally Posted by gehol View Post
    Not the model, it is the horse power. Frankly it is pretty well excepted that SEI is Chinese junk. There is a reason they are so cheap. I know the Mercury is obscenely expensive. Might look around for a good used one.
    Very good advice.
    _______

    Phil
    '09 Hewescraft ProV
    '09 150 Optimax


  17. Member
    Join Date
    Jun 2013
    Location
    LONGVIEW TEXAS
    Posts
    13,941
    #17
    MIKE your engine should have came with a 859399T13 service master gearcase same as standard 225 EFI have , now if you wanna upgrade to a much better gearcase the newer verado styled geared case 880686A43 is much more durable and even offered on the 250 pxs for some time , same gears as gen 2 torque master , both these p/n are for 20 in mtrs
    .................................................. ...the scariest thing in life is the unknown ...................................

  18. Member mikesjet's Avatar
    Join Date
    Aug 2009
    Location
    Shippensburg
    Posts
    814
    #18
    I decided to call SEI and talk to them. Yep they will sell you a lower for a 250, but they state very specifically that there isn't a warranty. I was told that for my motor the lower needs to have a different gear set and carrier. I asked if they sell the one with the correct one, answer, NO. Thanks for all the info, I had to hear it from the horse's mouth so to speak.

  19. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
    Join Date
    Apr 2008
    Location
    Greenville, SC (US)
    Posts
    94,945
    #19
    Quote Originally Posted by JOE54 View Post
    MIKE your engine should have came with a 859399T13 service master gearcase same as standard 225 EFI have , now if you wanna upgrade to a much better gearcase the newer verado styled geared case 880686A43 is much more durable and even offered on the 250 pxs for some time , same gears as gen 2 torque master , both these p/n are for 20 in mtrs
    The Parts Catalog does indeed show the G1-TM for this engine. Traditionally (with a couple exceptions) the early Servicemaster wasn't used on 250 models. The bearing on the FWD gear just didn't hold up well beyond 225.

    That 880686A43 is an excellent option- just be careful as there IS an offset-difference in the shift linkage so it's extremely critical shift adjustment be verified.


    Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
    Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
    Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor

  20. Member mikesjet's Avatar
    Join Date
    Aug 2009
    Location
    Shippensburg
    Posts
    814
    #20
    I am sure no one is on the edge their seat following this thread. I just want to Thank European Marine for all the advice and service they have given me over the phone. Today my Gen 1 Torquemaster arrived and I am so happy!!! I am going to install this Saturday hopefully get out and do some of the break in procedure.

Page 1 of 2 12 LastLast