thru hull exhust
+ Reply to Thread
Results 1 to 8 of 8

Thread:
thru hull exhust

  1. #1
    Junior Member
    Join Date
    Nov 2010
    Posts
    8

    Default thru hull exhust

    Maybe someone might have some advice with this problem! A buddy recently purchased a 1998/99 ulltra Stealth with thru hull exhust, below the swin step and at idle it shakes the whole boat and makes it feel as if it missing. any ideas on how to cure it? pm or call 1-520=444-0487 thanks Al
    Last edited by alboatsaz2; 09-12-2011 at 04:53 AM. Reason: added to post

  2. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  3. #2
    Senior Member EdonShano's Avatar
    Join Date
    Dec 2007
    Location
    Arroyo Grande
    Posts
    2,127

    Default

    Quote Originally Posted by alboatsaz2 View Post
    Maybe someone might have some advice with this problem! A buddy recently purchased a 1998/99 ulltra Stealth with thru hull exhust, below the swin step and at idle it shakes the whole boat and makes it feel as if it missing. any ideas on how to cure it? pm or call 1-520=444-0487 thanks Al
    tune it up....
    Formally know as UNFORGIVEN...

  4. #3
    Junior Member
    Join Date
    Nov 2010
    Posts
    8

    Default

    If it where that easy! If the boat is on the trailer in the water but the swin steps not touching the water it runs perfect, when you drop it in the water all the way in netural or in gear the whole boat shakes, once you bring the rpm up to 1,000/1200 range its almost quites shaking and any higher its perfect. we are going to put hose over the exhust and run it closer to being out from under the swin plate. was checking to see if any one had heard of this or had other ideas. thanks Al

  5. #4
    OBC Gestapo Bullhead Bully's Avatar
    Join Date
    Dec 2007
    Location
    AZ and So Cal
    Posts
    1,208

    Default

    Quote Originally Posted by alboatsaz2 View Post
    If it where that easy! If the boat is on the trailer in the water but the swin steps not touching the water it runs perfect, when you drop it in the water all the way in netural or in gear the whole boat shakes, once you bring the rpm up to 1,000/1200 range its almost quites shaking and any higher its perfect. we are going to put hose over the exhust and run it closer to being out from under the swin plate. was checking to see if any one had heard of this or had other ideas. thanks Al
    Sounds to me like the exhaust is getting trapped under the swim step creating and air pocket. I have seen this on molded swim steps before....as far as what to do.....maybe try to extend the tail pipes a few inches , enough to get the exhaust out.

    Or just get a sawsall and cut off the swim step. Just kidding...sorry couldn't resist.

    Seriously maybe call someone like IMCO who makes tailpipes and get there idea on it.

  6. #5
    Junior Member
    Join Date
    Nov 2010
    Posts
    8

    Default

    thanks for the input bullhead bully (great name) thats was our best guess but never thought about talking to the exhust people and of course the ultra peopl are no longer around. this boat has a couple of hunder hours on it and don't know how in the hell people could stand it. again thanks

  7. #6
    Junior Member
    Join Date
    Sep 2011
    Location
    Buckeye, AZ
    Posts
    23

    Default

    Sounds to me like the exhaust is under water. My jet boat does this too. But once you give her some fuel it blows the water out of it's way.

  8. #7
    Member
    Join Date
    May 2011
    Location
    Cerritos ca
    Posts
    45

    Default

    sounds like its under water like the last guy said...i have through transom exhaust thats half way in the water..it idles fine when its smooth but when a wake sloshes on the transom it does the same thing...

  9. #8
    New here Beer:30's Avatar
    Join Date
    Feb 2008
    Location
    Bakersfield, CA
    Posts
    4,219

    Default

    Nothing is free. Our friends Shockwave has the low-exh option, where large S-tubes snake the exh down below the swim step and thus- below the water line. It has Rex full-time mufflers, but the vibration/rumble is from the water being disturbed and the exh bubbles rapping against the swim step.

    Mine is ABOVE the water line and sound like two cannons - but no vibration from the disturbed water.

    There's not much to do - it's just a matter of hot air being blown into the water.

    The only option is to put a switchable exhaust on it, like "Captain's Call" or similar, where electric (or air powered) diverter valves send the exhaust down to exit from the center of the prop. This his how low-power setups are from the factory. There is a large Y-pipe that collects both exhaust sides and funnels them down to a bellow in the outdrive. It then channels the exhaust down to the hub of the prop and exits quietly.

    With this system, it can either be manual OR automatic. Some guys put a throttle switch on to activate the thru-prop at idle and then switch back when the throttle is advanced. Most just leave it manual on a switch.

    Would probably be $2,000 by the time it's all said and done. If the Y pipe is not in there already (usually removed / not installed when thru-hull is installed), you have to pull the motor to put it in. No choice on that part.
    Quote Originally Posted by gn7 View Post
    EFI is the wave of the future. There can be no denying it. Electronics have been on the leading edge of our entire lives. Not only os the magneto dead, but the standard issue CDI is wavering. Its all about total fuel, air AND spark control. Anybody that thinks its not has their head up their ass.


    2001 SleekCraft 30' Heritage SSB, open-bow mid-cuddy. 496HO / Bravo-I.

+ Reply to Thread

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Tags for this Thread

Digg This Thread

Posting Permissions

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

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93