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  • 105A Externally Regulated 8MR Custom Alternator

    $349.95 $339.95


     I Do Not Ship Alternators Internationally

    IMPORTANT:  All CMI Alternators are custom and may require a 3-4 week lead time.

    The CMI-105-ER

    This is the first and only Leece-Neville / Motorola case alternator I know of that is available & already set up for external regulation. What sets this alternator apart from an off the shelf unit are the components chosen to upgrade, tweak it and make it ready for installation. The alternator includes a billet machined 3/8" belt pulley, upgraded brush assembly, external regulation conversion and a spacer/bushing so it can fit either 1" or 2" mounts.

    External Regulator: 
    I can package this alternator with either a Balmar MC-614H or ARS-5H regulator. I recommend setting the Belt Manager feature to level three or four when setting up the regulator. It is also mandatory that an alternator temp sensor be used. I only recommend using Balmar regulators with this alternator.

    CMI-105-ER Specifications:

    This is not a cheaply built re-badged automotive alternator with a dumb internal regulator. This is a marine alternator spark protected with a single 1" or 2" foot. The 1" to 2" spacer is included and is a $26.00 accessory. This 105A medium duty externally regulated alternator intended to replace the stock alternators found on many Westerbeke or Universal diesel engines. It will fit any engine that uses an 8MR style alternator.

    This alternator fills the gap between a true high performance alternator (see my other alternator offerings) and the factory alternator. It was designed to meet a price and performance niche not available to boaters previously. This is a what I consider a medium/light duty alternator intended for smaller banks that just need healthier charging profile. It is not intended to drive large AGM banks, large flooded banks or large GEL banks. See my other alternator offerings for this type of use.


    The CMI-105-ER comes standard with a tachometer output studs (stator tap) for diesels that run the tachometer sense off the alternator. Not all engines drive the tachometer from the alternator, but most Westerbeke and Universal engines do. The CMI-105-ER is set up for external regulation only. It has no internal regulator. You will need an external regulator to install this alternator.

    Special features:

  • Intended to fit many Universal & Westerbeke diesels that use an 8MR Leece-Neville
  • 105A cold rated, with good high idle performance.
  • Machine wound stator of 14GA top quality magnet wire means better cooling and higher temperature tolerance.
  • Precision machined rotor and slip rings for greater contact at all RPM.
  • High performance diode rack.
  • Unidirectional Fan
  • Billet Machined Steel Pulley - 2.6" Diameter X 3/8" or 10mm Belt (I have these custom machined 1/2" on request)
  • Brushes are high copper content not run of the mill carbon brushes. This yields superior conductivity and considerably longer brush life.
  • Ready to accept an external regulator (I recommend only Balmar regulators).
  • Isolated ground for steel or aluminum boats or for using a shunt in the negative path..
  • Hand converted & modified by Compass Marine in Maine, USA