Thanks Thanks:  0
HaHa HaHa:  0
Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: not accel as I think it should

  1. #1
    Join Date
    May 2009
    Location
    Kearney Mo.
    Posts
    3,680
    Post Thanks / Like

    Default not accel as I think it should


    Hello. I bought a 99 nitro 185 sport with a 120 2 cycle force mercury. My concern is when I am taking off it revs under load to 3500 then shoots to 5500 with no more thrust. It does not slow down, its still accelerating but just not any different. It does take a bit to plane out. The best way I can describe it if the prop is pulling in air allowing the load to decrease and the engine to rev. Once it planes out the rpm drops to say 4800 and you are running 30 with about 10 more to go before it maxes out. I (not knowing boats that well) was thinking a dolphin tail might help if it is in fact pulling air into the prop. Anyone have any good suggestions? Or what I might do to test it.

  2. #2
    Join Date
    Mar 2014
    Location
    TN
    Posts
    1,371
    Post Thanks / Like

    Default

    Be sure your trimmed all the way down on take off
    PROUD MEMBER OF TEAM GEEZER

  3. #3
    "G"'s Avatar
    "G" is offline Super Duper Moderator - 2012 Crappie.Com Man of the year & 2018 Crappie.com Decade of Exceptional Service Awards * Crappie.com Supporter * Member Sponsor
    Join Date
    Aug 2008
    Location
    Belden, MS
    Posts
    95,225
    Post Thanks / Like

    Default

    May need a prop with a little more pitch
    I have spent most my life fishing........the rest I wasted.
    PROUD MEMBER OF TEAM GEEZER
    PICO Lures Field Rep

  4. #4
    Join Date
    Jun 2009
    Location
    Leslie
    Posts
    4,396
    Post Thanks / Like

    Default

    If it is pulling air, a fin might help. I agree with "G" though, prop with a little more pitch may also help.

    I would also have someone look at how the motor is hung. Trimmed all the way out may not leave the motor at a 90 degree (or proper angle) to the hull. Might be as simple as that.
    I have OCD "Obsessive Crappie Disorder"

  5. #5
    Join Date
    Jan 2014
    Location
    Missouri
    Posts
    48
    Post Thanks / Like

    Default

    Make sure the motor is mounted as low on the tramson as it can be.

  6. #6
    NIMROD's Avatar
    NIMROD is offline Crappie.com Legend - Kids Corner Moderator
    Join Date
    Jan 2005
    Location
    Plainview, / Russellville , Arkansas
    Posts
    16,739
    Post Thanks / Like

    Default

    Sure prop hub not slipping ?
    Moderator of Beginners n Mentoring forum
    Takeum Jigs

    Likes wannabe fisherman LIKED above post

  7. #7
    Join Date
    Sep 2012
    Location
    Dayton Tennessee
    Posts
    39,760
    Post Thanks / Like

    Default

    If it used to run better set up the way it is then I am with Nimrod of the hub may be slipping.
    The love for fishing is one of the best gifts you can pass along

  8. #8
    Join Date
    Oct 2014
    Location
    Lexington,SC
    Posts
    613
    Post Thanks / Like

    Default

    Quote Originally Posted by NIMROD View Post
    Sure prop hub not slipping ?

    This would be my first guess also.........mark the hub/prop with a permanent marker then go for a ride, check marks if they have moved you know it's a spun hub.

    Also I would think a foil would make the problem worse as a foil lifts the stern of the boat.

    Does the boat have a jackplate on it, maybe the motor is lifted a tad too much
    Three can keep a secret................If two of them are dead! (Benjamin Franklin)

  9. #9
    Join Date
    May 2009
    Location
    Kearney Mo.
    Posts
    3,680
    Post Thanks / Like

    Default

    Thanks for all the ideas I appreciate it. I'll mark the hub to make sure. I am stumped on the prop however. I went to Mercury marine and went thru the prop selector as I was curious to see if I had the right prop to begin with, but all it gave me was their recommended replacements. It is a Lazer two and the numbers on it are 48-16990 and the pitch is 20 any ideas?/

  10. #10
    Join Date
    Jul 2014
    Location
    Sibley, Louisiana
    Posts
    498
    Post Thanks / Like

    Default

    Whatever the pitch, it shouldnt be revvin like that...its either the prop hub is spun or your cavitating. the first set of fins right above the prop (anti-cavitation plate) should be level with the bottom of the boat - as a general rule to start. You can gradually raise to give you more top end speed. Until cavitation becomes an issue. Same with trimming - take off with it all the way down, then gradially trim up once on plane till you hear the rpms increase - then back down a hair and youre in the zone. Of course all this varies with different boats.. it takes lots of experimenting and adjusting till you get it right.

Page 1 of 2 12 LastLast

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

BACK TO TOP