Shop Marine How
  • Mark Grasser/CMI High Performance Small Case Marine Alternators - Starting At:

    $599.00 $559.00
    Please enter your marine engine model and alternator belt width or type.


     Click Here For International Shipment Info

    Compass Marine Inc. / has teamed up with fellow Mainer Mark Grasser, of Mark Grasser DC solutions, to offer a tremendous value in a small case performance alternator. Mark is building these to the CMI specs to create a high performance product at a reasonable price point.

    Please email me before ordering so we can ensure fit. (compassmarineservices at gmail dot com)

    This alternator is available with a 1", 2" or Yanmar/Hitachi 3.15" dual foot mount option. If you would like isolated ground this adds $99.00 and is a special order. The case ground works fine and keeps the pricing within a reasonable range.

    Please specify whether you want a 3/8" pulley or a 1/2" pulley.

    I can also offer serpentine pulley kits please mail me to ensure proper fitment.

    This is not a lightly built re-badged automotive alternator with poor low end performance. These are hand built in Maine USA to our stringent specifications to ensure a quality product.

    They come standard with a tachometer output (stator tap) for diesels that run the tachometer sense off the alternator. These alternators are set up for external regulation and also have an internal regulator for emergency redundancy.

    Special features:

    • Available in 1" Foot, 2" Foot and 3.15" Yanmar/Hitachi saddle mounts.
    • Hand wound stator wound from 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.
    • Tight tolerance stator/rotor gap for better performance. A feature not found in standard alternators.
    • Precision milled stator utilizing a special dacron/mylar insulator. The industry norm is paper.
    • Rotor is precision balanced to .015 ounce inches. Industry norm is .050 - .090. This means SMOOTH operation and less harmonics.
    • 50A press fit diodes. Industry standard is Chinese button diodes and 25-30A rated. These diodes carry a performance rating to 300F.
    • Internal wire leads are ultra high temperature acrylic coated fiberglass insulation sleeves or high temp 200C silicone wire not cheap rubber or PVC sleeving.
    • Brushes are high copper content composite not run of the mill carbon brushes. This yields superior conductivity and considerably longer brush life.
    • The positive stud is a beefy 5/16" not some wimpy 1/4" or #10 stud. These studs are bolted directly to the rectifier bridge for the best possible connection. Industry standard is a compression fit.
    • Manufactured to match the offsets of my competitors (eg; a Balmar 6 series) so it can be converted to a serpentine kit in the future.
    • All stainless draw bolts, pivot bolts and adjustment bolts a feature not found on any of my competitors products.
    • Built for external regulation with an additional standard internal regulator as emergency back up.
    • Please specify a 3/8" or 1/2" pulley unless going with a serpentine kit.
    • Can be built with a case isolated ground for steel or aluminum boats.
    • Hand built in the USA (Note: some internal components are non US made but carefully chosen)
    • Built to marine standards for ignition protection.
    • Universal adjustment ear for wider fit tolerance.
    • Machined, drilled & tapped alternator temp sensor mount point