Acceptable Axial Runout?

Discussion in 'Props' started by Tedd McHenry, Jun 20, 2023.

  1. Tedd McHenry
    Joined: Feb 2020
    Posts: 54
    Likes: 8, Points: 8
    Location: Surrey, BC, Canada

    Tedd McHenry Junior Member

    I dinged my propeller a bit and I'm trying to assess the damage. I've measure the axial runout but, unfortunately, I didn't measure the runout on the blades when I got the prop and I haven't been able to find a specification for it. It's a fine pitch, four-bladed prop on a Suzuki DF9.9B.

    There's 0.0250" (0.64 mm) variation in the leading edge axial positions and 0.030" (0.76 mm) variation in the trailing edge axial positions. Some are in the same direction (i.e., entire blade tip forward or aft) and some are in the opposite direction (i.e., cord line angle greater or lesser).

    This is more than I would have expected on a new prop but I've never measured one. Can anyone provide guidance? I don't notice any particular problem with the prop's performance but the damage happened on my first trip with the boat (d'oh!) so I wouldn't necessarily perceive a small abnormality.
     
    Tedd McHenry, Jun 20, 2023
    #1
  2. jehardiman
    Joined: Aug 2004
    Posts: 3,773
    Likes: 1,167, Points: 113, Legacy Rep: 2040
    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    Those are cast props, so those measurements aren't really that bad. I'd just check the pitch at 0.7r and balance and fix it if it needs it.
     
    jehardiman, Jun 21, 2023
    #2
    Tedd McHenry likes this.
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