Propulsion

Discuss marine engines, drives, and propulsion systems.

  1. Props

    Propeller selection, performance comparison, prediction, experience, and modification.
    Discussions:
    543
    Messages:
    6,440
    Latest: The mystery of a proper prop and terrible performance sdowney717, Jul 22, 2025
    RSS

  2. Surface Drives

    Surface Drives. Arneson, BPM, Seafury, PSI, Levi, Etc.
    Discussions:
    185
    Messages:
    2,862
    Latest: Is Levi Drives still in business? BlueBell, May 30, 2025
    RSS

  3. Jet Drives

    Jet Drives (pumps, impellers, etc.)
    Discussions:
    464
    Messages:
    4,474
    Latest: Affordable Water Jets? RSD, Sep 1, 2025
    RSS

  4. Outboards

    2-stroke and 4-stroke outboard motors.
    Discussions:
    1,049
    Messages:
    10,172
    Latest: Yamaha 5BS L661 Owners/Repair Manual Padmack, Nov 8, 2025 at 10:27 PM
    RSS

  5. Sterndrives

    Stern drive lower and upper units, transom and gimbal assemblies, steering, and trim pumps. Mercruiser (Alpha One, Alpha One Generation II, Alpha SS, Bravo One, Bravo Two, Bravo Three, Bravo XR Sportmaster, TRS, Speed Master), IMCO, ILMOR, Konrad, OMC, Volvo Penta
    Discussions:
    552
    Messages:
    3,882
    Latest: Mercruiser Alpha 1 gen 2 gonzo, Oct 11, 2025
    RSS

  6. Pod Drives

    Volvo IPS, ZF, CMD Zeus, and other pod-drive systems
    Discussions:
    29
    Messages:
    299
    Latest: 50-200 hp electric pod with nozzle and motor on hub? ram68ocean, Jul 5, 2021
    RSS

  7. Inboards

    Inboard and Vee-drive hardware: struts, stuffing boxes, transmissions, coolers
    Discussions:
    540
    Messages:
    5,022
    Latest: Best practices for propeller shaft installation? Mark Willoughby, Oct 20, 2025
    RSS

  8. Diesel Engines

    Diesel Engines
    Discussions:
    692
    Messages:
    8,642
    Latest: Problem with Yanmar 2QM15 gonzo, Oct 14, 2025
    RSS

  9. Gas Engines

    Gasoline Engines
    Discussions:
    423
    Messages:
    4,652
    Latest: Anyone need a torque monster 383 SBC? gonzo, Sep 24, 2024
    RSS

  10. Electric Propulsion

    Electric propulsion systems
    Discussions:
    109
    Messages:
    2,176
    Latest: samarium cobalt brushless motors portacruise, Oct 17, 2025
    RSS

  11. Hybrid

    Hybrid propulsion such as diesel electric, hydraulic.
    Discussions:
    211
    Messages:
    5,275
    Latest: Hydraulic Drive for max efficiency Rumars, May 6, 2025
    RSS

  12. DIY Marinizing

    A forum to discuss "do it yourself" marinizing of engines / conversion of automotive engines to marine use.
    Discussions:
    276
    Messages:
    5,578
    Latest: VW/AUDI 3.0TDI marinising Radu Druncea, Jul 2, 2025
    RSS
Page 1 of 25
Sort By:
Title Start Date
Replies Views
Last Message ↑
  1. Willallison

    Trolling valves

    Willallison, Feb 13, 2003 ... 2
    Replies:
    17
    Views:
    36,650
    Willallison
    Feb 27, 2003
  2. 8knots

    Us Distributor For Lister Petter

    8knots, Mar 18, 2004
    Replies:
    1
    Views:
    4,148
    Corpus Skipper
    Mar 23, 2004
  3. fisherman

    duo-prop shaft design

    fisherman, May 29, 2004
    Replies:
    8
    Views:
    7,651
    yipster
    Jul 9, 2004
  4. LKJR

    Fuel Injection?

    LKJR, Jul 14, 2004
    Replies:
    0
    Views:
    4,751
    LKJR
    Jul 14, 2004
  5. vegasss

    1990 60hp johnston motor

    vegasss, Jul 1, 2004
    Replies:
    3
    Views:
    4,686
    pungolee
    Jul 17, 2004
  6. Phosphor

    Motor Materials

    Phosphor, Jul 17, 2004
    Replies:
    3
    Views:
    5,066
    Black Swan
    Jul 18, 2004
  7. Mynx

    Prop vs. Jet on Outboard Lower Unit

    Mynx, Jul 19, 2004
    Replies:
    1
    Views:
    6,039
    Willallison
    Jul 20, 2004
  8. Harrible

    Powering Help

    Harrible, Jul 13, 2004
    Replies:
    4
    Views:
    4,703
    mmd
    Jul 22, 2004
  9. stant1man

    Phase 1: Please help with engine!

    stant1man, Jul 16, 2004
    Replies:
    11
    Views:
    11,179
    TheFisher
    Jul 22, 2004
  10. lake guy

    Water in oil 5.0 stern drive 1985

    lake guy, Jul 18, 2004
    Replies:
    5
    Views:
    8,227
    gonzo
    Jul 24, 2004
  11. woodstockwizzar

    V P 270 sotdrive upgrade?

    woodstockwizzar, Jun 24, 2004
    Replies:
    14
    Views:
    5,599
    woodstockwizzar
    Jul 28, 2004
  12. diversion

    back fire

    diversion, Jul 23, 2004
    Replies:
    6
    Views:
    5,894
    Frans X L
    Aug 1, 2004
  13. horsechow

    Water in Cylinders

    horsechow, Aug 3, 2004
    Replies:
    5
    Views:
    4,416
    Corpus Skipper
    Aug 4, 2004
  14. BIG MAC

    engine suppliers

    BIG MAC, Aug 8, 2004
    Replies:
    4
    Views:
    3,854
    BIG MAC
    Aug 11, 2004
  15. guestCarol

    outdrive water pump on i/o 3.0 alpha mercruiser?

    guestCarol, Aug 5, 2004
    Replies:
    8
    Views:
    18,896
    yipster
    Aug 13, 2004
  16. yipster

    merc diagnose

    yipster, Aug 12, 2004
    Replies:
    2
    Views:
    5,207
    yipster
    Aug 14, 2004
  17. jackb

    Outdrive/Outboard Hydrofoils

    jackb, Aug 15, 2004
    Replies:
    2
    Views:
    7,857
    jackb
    Aug 16, 2004
  18. Tucker

    Manifold Cleaning

    Tucker, Aug 24, 2004
    Replies:
    2
    Views:
    5,652
    gonzo
    Aug 25, 2004
  19. davy jones

    prop shaft read out at packing gland

    davy jones, Sep 2, 2004
    Replies:
    0
    Views:
    4,970
    davy jones
    Sep 2, 2004
  20. wake711

    weedwacker? will it work

    wake711, Sep 5, 2004
    Replies:
    2
    Views:
    3,380
    Dutch Peter
    Sep 6, 2004
  21. Dutch Peter

    Mercury Outboard Info

    Dutch Peter, Sep 10, 2004
    Replies:
    1
    Views:
    6,860
    yipster
    Sep 10, 2004
  22. Monark

    Outboard setup

    Monark, Sep 12, 2004
    Replies:
    2
    Views:
    3,911
    gonzo
    Sep 13, 2004
  23. Steve H

    How much angle can a driveline handle??

    Steve H, Sep 9, 2004
    Replies:
    8
    Views:
    6,333
    Steve H
    Sep 15, 2004
  24. Glasply-Cruiser

    Merc Cruiser 470 - Stern drive type?

    Glasply-Cruiser, Sep 14, 2004
    Replies:
    1
    Views:
    8,466
    Corpus Skipper
    Sep 15, 2004
  25. fcfc

    silly question ?

    fcfc, Sep 16, 2004
    Replies:
    1
    Views:
    3,523
    jehardiman
    Sep 16, 2004
  26. jfc52

    sea ray prop for planing

    jfc52, Aug 24, 2004 ... 2
    Replies:
    20
    Views:
    25,930
    firestorm
    Sep 17, 2004
  27. ted Cichecki

    Fuel tank capacity ,outdrive dependibility

    ted Cichecki, Sep 19, 2004
    Replies:
    0
    Views:
    4,458
    ted Cichecki
    Sep 19, 2004
  28. piping-hot

    Which outdrive?

    piping-hot, Sep 22, 2004
    Replies:
    0
    Views:
    3,683
    piping-hot
    Sep 22, 2004
  29. seacraft23

    mercury 200 1999 bushings

    seacraft23, Sep 24, 2004
    Replies:
    0
    Views:
    3,844
    seacraft23
    Sep 24, 2004
  30. finley

    Shave engine heads

    finley, Jun 15, 2004
    Replies:
    11
    Views:
    15,311
    woodboat
    Sep 28, 2004
  31. jfblouin

    Selfbuilding of a Jet-Drive system

    jfblouin, Sep 8, 2004
    Replies:
    10
    Views:
    6,985
    Tall Timber
    Sep 30, 2004
  32. Pat B

    Engine Torque Curves

    Pat B, May 6, 2004 ... 2
    Replies:
    22
    Views:
    28,322
    Brian Boulter
    Oct 6, 2004
  33. FAST FRED

    Numbers Crunched?

    FAST FRED, Oct 1, 2004
    Replies:
    2
    Views:
    3,776
    MikeJohns
    Oct 13, 2004
  34. Guest

    Alignment Blues

    Guest, Sep 15, 2004 ... 2
    Replies:
    17
    Views:
    9,151
    MikeJohns
    Oct 13, 2004
  35. George Askew

    Diesel Outboards

    George Askew, Sep 12, 2004
    Replies:
    7
    Views:
    7,367
    nero
    Oct 20, 2004
  36. mselle

    2 small waterjets in a 8 m boat

    mselle, Sep 5, 2004
    Replies:
    3
    Views:
    4,362
    hmattos
    Oct 23, 2004
  37. WinFlex

    Engine Replacement

    WinFlex, Jul 2, 2002
    Replies:
    14
    Views:
    15,552
    Jacob Fishing
    Oct 24, 2004
  38. rod fox

    Prop-walk

    rod fox, Oct 31, 2004
    Replies:
    7
    Views:
    8,968
    Eric Sponberg
    Nov 8, 2004
  39. ADRIAN77

    Difficult To Find Book

    ADRIAN77, Nov 10, 2004
    Replies:
    0
    Views:
    3,212
    ADRIAN77
    Nov 10, 2004
  40. Ben Lindenberg

    Offset single prop - which direction?

    Ben Lindenberg, Oct 15, 2004
    Replies:
    7
    Views:
    10,000
    Eric Sponberg
    Nov 10, 2004
Showing threads 1 to 40 of 991

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