Stuart Marine Engine R3M ignition timing question

Discussion in 'Help Wanted' started by Bob Jennings, Apr 11, 2020.

  1. Bob Jennings

    Bob Jennings New Member

    I purchased a Stuart Marine Engine R3M/MC manual from the Museum. It is issue 28 (5th edition) price 2/- and states the ignition timing is set at about 1" from TDC. I also have a copy of the same manual but a later edition 28c , price 3/- which states timing is set at about 1.5". The manuals otherwise are virtually identical. Do you know why there is a difference? Did the design change in any way? My engine runs ok at 1.5" but I am going to test it by further retarding it towards the 1" mark. Thanks for any comments Bob
     
  2. petternut

    petternut Administrator

    The early ones had a Miller flywheel magneto and later one a Lucas SR.
     
  3. Bob Jennings

    Bob Jennings New Member

    Yes mine has a Lucas SR1 magneto - the earlier manual does show a separate magneto exactly as the later one
     
    Last edited: Apr 12, 2020
  4. petternut

    petternut Administrator

    and the Miller was earlier still. I had a manual but lent it out and never got it back.
     
  5. Skankin_giant

    Skankin_giant Active Member

    R3 were fitted with.
    WICO WBC Flywheel Magneto
    Miller Flywheel Magneto
    Lucas N1 (very few)
    WICO A type
    WICO FW Flywheel magneto
    Lucas RS/SR 1.

    So there might be a bit of variation in the manuals. IIRC the ignition timing is on the rim of the flywheel?
     
  6. petternut

    petternut Administrator

    Thanks for filling in the list Steve. I presume that the flywheel mags were larger diameter than the Flywheel and therefore a used a smaller dimension of timing. The Miller I had certainly was.
     
  7. Skankin_giant

    Skankin_giant Active Member

    Yep, the WICO FW was slightly smaller than the WBC and Miller but over all larger than the standard flywheel. The Miller unit fitted inside the WBC outer flywheel which was just a weight on the WICO WBC and didn't hold any magnets. These were on a central hub and from what I can find were unreliable hence the Miller unit were implemented.

    My engine which had the WICO WBC was plated at 1 1/4hp 1450RPM rather then 1 1/2hp at 1500RPM, which I thought was odd.
     
  8. petternut

    petternut Administrator

    Is Mike H still around?
     
  9. Skankin_giant

    Skankin_giant Active Member

    Don't know, but he might come out to correct me soon.... finally compiled my Stuart Turner stuff.
     

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