28 hp kubota inboard rough vibration

Discussion in 'Diesel Engines' started by marsh trapper, May 26, 2015.

  1. marsh trapper
    Joined: Feb 2015
    Posts: 21
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: maryland

    marsh trapper Junior Member

    Hey guys I have a small deadrise workboat with a 28 hp kubota inboard 4 cylinder diesel that vibrates rough n really bad when throttle is all the way down
     
  2. steve123
    Joined: Dec 2014
    Posts: 59
    Likes: 2, Points: 0, Legacy Rep: 20
    Location: China

    steve123 Junior Member

    Has it always been like that or just started ?
     
  3. marsh trapper
    Joined: Feb 2015
    Posts: 21
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: maryland

    marsh trapper Junior Member

    I just bought boat but guy said its always been like that...as soon as I bump it up some it smooths right out and is normal
     
  4. whitepointer23

    whitepointer23 Previous Member

    If you mean idle is rough just bump it up a little bit on the adjustment screw.
     
  5. steve123
    Joined: Dec 2014
    Posts: 59
    Likes: 2, Points: 0, Legacy Rep: 20
    Location: China

    steve123 Junior Member

    Yeah, whats the idle rpm...maybe need to increase slightly.
     
  6. marsh trapper
    Joined: Feb 2015
    Posts: 21
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: maryland

    marsh trapper Junior Member

    Not sure what rpm is ill che k..and where is the idle screw
     
  7. marsh trapper
    Joined: Feb 2015
    Posts: 21
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: maryland

    marsh trapper Junior Member

    O and this rough vibration happens in neutral and n gear
     
  8. marsh trapper
    Joined: Feb 2015
    Posts: 21
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: maryland

    marsh trapper Junior Member

    I believe my motor is a beta 28
     
  9. whitepointer23

    whitepointer23 Previous Member

    Have a look at the injector pump the idle screw is the the one touching the throttle lever at idle position. Just loosen the lock nut and turn the screw clockwise. You should need less than a 50 rpm increase to make the idle smooth.
     
  10. marsh trapper
    Joined: Feb 2015
    Posts: 21
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: maryland

    marsh trapper Junior Member

    Thank u thats what I was thinking too .it vibrates rough in gear too I noticed yest ..of courrse the rpm gauge wont properly work...would I have to get a kubota rpm gauge or would any work ..? Her mac rpm id 3600 and from reading on forums idle rpm should be 900
     
  11. marsh trapper
    Joined: Feb 2015
    Posts: 21
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: maryland

    marsh trapper Junior Member

    Further looking it it a phasor 28 hp (on a kubota block) and its a 3 cylinder ..
     

  12. marsh trapper
    Joined: Feb 2015
    Posts: 21
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: maryland

    marsh trapper Junior Member

    And today checked oil for first time since buyin it and no oil at all (of course)..ughhh..and the previous owner said they took it out a few weeks ago..tomorrow ima put oil in and hope this guy didnt rip me off..I shoulda checked oil befor hand...and ive been down past few days starting it ..but not letting it run long in slip..what u guys think?
     
Loading...
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.