Scandy White Tunnel, prop only gets 5300 rpm

Discussion in 'Props' started by Jwil, Sep 10, 2014.

  1. Jwil
    Joined: Sep 2014
    Posts: 3
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Georgia

    Jwil New Member

    Brand new scandy white tunnel boat with hydralic lift and Mercury 150 four stroke, prop is power tech OFX 17p 15 1/2 D 4blade. Can only get 5300 rpm and 41 mph top speed. I was told this boat should do 50 mph easy. I got a 4 blade prop for the hole shot as runing skinny is what it was made for, any help would be appreciated. Motor is rated for 5800 rpm
     
  2. CDK
    Joined: Aug 2007
    Posts: 3,324
    Likes: 148, Points: 63, Legacy Rep: 1819
    Location: Adriatic sea

    CDK retired engineer

    Two reasons:

    The engine needs several hours to run in, running full throttle is not the way to treat a new engine.

    A 4 blade prop has more drag than a 3 blade one. It can push heavier loads at mid range but the top speed is lower.
     
  3. philSweet
    Joined: May 2008
    Posts: 2,339
    Likes: 201, Points: 63, Legacy Rep: 1082
    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

    After motor is broken in, you need to check the timing. I don't know about the new ones, but the old ones were shipped with any old timing, usually delayed a few degrees, probably to stop people from grenading them in the first ten hours.
     
Loading...
Similar Threads
  1. rfleet1066
    Replies:
    5
    Views:
    1,388
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.