Please note this thread has been inactive for 90 days. For the best results, please start a new thread.
Results 1 to 8 of 8
  1. #1
    Cadet danielw71's Avatar
    Join Date
    Apr 2012
    Location
    South Carolina
    Posts
    13

    Default 1987 3.0L MerCruiser Alternator

    Tback of my alternator fell off.
    After looking at mercruiserparts.com I came up with 5 different possibilities they are all out dated, I cross referenced part numbers and iboats.com has a few to choose from starting at 168.99 to 201.80 they were Sierra 68 amp, Arco 105 amp & Mallory ? amp.
    I also found on ebay.com a Delco 110 amp that matches for 69.00.
    All alternators are marine, is there a reason I should not get the Delco?

  2. #2
    Honorary Moderator Emeritus Don S's Avatar
    Join Date
    Aug 2004
    Location
    Western WA.
    Posts
    62,323

    Default Re: 1987 3.0L MerCruiser Alternator

    Why do you need such a big alternator for a 3.0L? You do realize that the bigger the alternator, the more HP it takes from the engine to run it.

    As long as the mounting for the alternator is the same, you can use the larger Delco, just be sure to use a larger orange wire to the starter. It is only 8 ga now, sized for the 50 - 65 amp range.
    Don S.


    Please, no PM's (Private Messages) regarding boat/engine problems.
    That is what the forums are for.
    Only forum/moderator issues will be answered in PM's.

  3. #3
    Cadet danielw71's Avatar
    Join Date
    Apr 2012
    Location
    South Carolina
    Posts
    13

    Default Re: 1987 3.0L MerCruiser Alternator

    Ok thanks the wire broke when it fell so I will have to change it anyway.
    6 ga should be enough right?
    How much of a differance would it make in the HP?
    Since the Sierra was 65 amp and the Arco was 105 amp I was not sure if it would make a big differance, as to the useage I dont evan have a radieo right now but if I can save $100.00 to $200.00 I think it would be worth it.

  4. #4
    Honorary Moderator Emeritus Don S's Avatar
    Join Date
    Aug 2004
    Location
    Western WA.
    Posts
    62,323

    Default Re: 1987 3.0L MerCruiser Alternator

    Take your alternator to your local starter/alternator/electric motor shop. They can probably fix your alternator cheaper than any dirt cheap off shore high amp alternator. And it will probably last longer ................ if you don't drop it.
    Don S.


    Please, no PM's (Private Messages) regarding boat/engine problems.
    That is what the forums are for.
    Only forum/moderator issues will be answered in PM's.

  5. #5
    Cadet danielw71's Avatar
    Join Date
    Apr 2012
    Location
    South Carolina
    Posts
    13

    Default Re: 1987 3.0L MerCruiser Alternator

    LOL
    I was going to take it to someone but two of the wires for the stator are broken and the rotor has been rubbing stator pretty bad I think was rebuilt before and not done right.
    I guess I need to add checking the bolts holding the alternator together to my winterizing list.

  6. #6
    Seaman Apprentice
    Join Date
    Nov 2010
    Posts
    36

    Default Re: 1987 3.0L MerCruiser Alternator

    if it was the one from "DB ELECTRICAL" on ebay, they are local to me, and I am running that alternator on my 1988 3.0

  7. #7
    Cadet danielw71's Avatar
    Join Date
    Apr 2012
    Location
    South Carolina
    Posts
    13

    Default Re: 1987 3.0L MerCruiser Alternator

    Quote Originally Posted by jeremy_nash View Post
    if it was the one from "DB ELECTRICAL" on ebay, they are local to me, and I am running that alternator on my 1988 3.0
    Yes that is the one I ordered.
    Did you use the origanal wiring?

  8. #8
    Fleet Admiral HT32BSX115's Avatar
    Join Date
    Dec 2005
    Location
    WA
    Posts
    7,799

    Default Re: 1987 3.0L MerCruiser Alternator

    Quote Originally Posted by danielw71 View Post
    LOL
    I was going to take it to someone but two of the wires for the stator are broken and the rotor has been rubbing stator pretty bad I think was rebuilt before and not done right.
    I guess I need to add checking the bolts holding the alternator together to my winterizing list.
    Ok, then take it to a reputable rebuild shop so they can do it "right"!

    I'll bet there's more than one available.....
    73 de Rick
    ----------------------------------------------------------------------------------
    I use xxx oil and have never had a problem........
    1987 FourWinns 211 Liberator, 7.4L- Bravo III installed by ME,
    Formerly OMG 460 King Kobra powered
    1947 Stinson 108-2 Station Wagon
    , Franklin 6A-335B. Hartzell CS 2-blade prop
    -
    All PM's cheerfully answered! Please ask tech questions in the appropriate forum so everyone's included

Similar Threads

  1. 1987 mercruiser 470
    By warrenw7805 in forum Mercruiser I/O & Inboard Engines & Outdrives
    Replies: 0
    Last Post: April 7th, 2012, 07:49 PM
  2. 1987 mercruiser
    By bmain11 in forum Mercruiser I/O & Inboard Engines & Outdrives
    Replies: 10
    Last Post: July 27th, 2011, 05:35 PM
  3. 1987 3.0 Mercruiser
    By cnahorn in forum Mercruiser I/O & Inboard Engines & Outdrives
    Replies: 3
    Last Post: June 29th, 2010, 09:08 PM
  4. 1987 Mercruiser 3.0L
    By labguy in forum Mercruiser I/O & Inboard Engines & Outdrives
    Replies: 3
    Last Post: May 26th, 2009, 03:50 PM
  5. 1987 Mercruiser
    By gvarney13 in forum Mercruiser I/O & Inboard Engines & Outdrives
    Replies: 0
    Last Post: July 1st, 2007, 10:17 PM
  1. iboats Forum Directory - Over 100,000 forum posts organized by topic