Page 1 of 2 1 2 LastLast
Results 1 to 10 of 11
  1. #1
    DAGO RACING CREW 97GPSLEEPER's Avatar
    Join Date
    Apr 2006
    Location
    Orange, TX
    Posts
    4,228
    +1
    169

    Gains From Bilge Siphon Removal & Spout Block Off

    In February I will be testing a few new things on my ski. Have any of you removed the bilge siphon tube & blocked off the visibility spout? If so, what kind of gain did this yield?

    I will also be testing the Wetwolf Cone. I am hoping to pick up atleast a 1mph with the cone and another with the above mods, for a total of 2mph.

    I am also going to rebuild the carbs, it runs fine but I am pushing my luck as the carbs have not been rebuilt since 2002. The check valves are known to crease and cause lean seizures.

    Any comments on these mods? Thanks.


  2. #2
    My son (mohawk man) jeffsntx's Avatar
    Join Date
    Sep 2006
    Location
    Belton TX
    Posts
    2,598
    +1
    1
    I would doubt that the siphon tube and spout block offs give you any MPH gain. It will probably give you a few RPM's so if you can repitch just a little it might yield a little MPH. I dont have any experience with the AAT cone. Let us know what you find out. Do 1 mod at a time to see what each one gains.

  3. #3
    Yamaha tow boat RIDEALLDAY's Avatar
    Join Date
    Feb 2006
    Location
    Texas
    Posts
    1,447
    Get that visibility spout off of there, the people that ride with you will thank you. I'm sure you already have it blocked off.
    No speed gains though. Just a dry back.

  4. #4
    DAGO RACING CREW 97GPSLEEPER's Avatar
    Join Date
    Apr 2006
    Location
    Orange, TX
    Posts
    4,228
    +1
    169
    I do not have it blocked off yet. I figure ever little bit helps, why have that water going through the rear deck when it can be going out the nozzle. The bilge siphon tube really looks like an obstruction. If I do not gain anything with removing it, I still think it will be beneficial when combined with the AAT cone because the AAT cone pulls the RPM down about by making the nozzle smaller at topspeed. If removing the siphon tube allows for a 50 RPM gain and the fact this obstruction will be gone, the AAT will have a chance to work more effeciently.

  5. #5
    cheatin' piston popper addicted's Avatar
    Join Date
    Jul 2006
    Location
    north jersey
    Posts
    6,188
    +1
    176
    I've read of a few tenths from blocking off the spout and bilge. I am in the process of doing that , but I won't have any #'s until april or may. The AAT is worth at leat 1mph, depending on your prop. If you are slightly under pitched, you will get better results than if you have the "perfect" prop. It WILL help you get there faster regardless.

  6. #6
    RAIDER RUNNER BULLRAIDER's Avatar
    Join Date
    Nov 2005
    Location
    HOUSTON TEXAS
    Posts
    651
    97.this subject has been debated many times, here is my take, ALL small things CAN add up, i dont think alone one small tube removal will increase you one mph, but a few small things WILL add up, just remember the people that said filling the rideplate holes wouldnt help either, I know on my ski the tubes are removed, and other small things have been done and it has picked up a few more mph than another one like it, i dont think i have a special ski ,I just try and remove all drag...restriction and do all the things to make it eek out one more mph, I say do it.......another alternative put a valve on the spout if you want to keep it for visibility, if not cut that dude off..........

  7. #7
    DAGO RACING CREW 97GPSLEEPER's Avatar
    Join Date
    Apr 2006
    Location
    Orange, TX
    Posts
    4,228
    +1
    169
    I gained 1mph from filling in the rideplate & intake grate holes. Between the AAT cone, removing the siphon tube, and blocking off the pisser, I think a 2mph gain is possible. I am not going to do any additional motor mods, my set up is too reliable. So now I stay interested in this ski by doing the little things and dressing it up cosmetically.

  8. #8
    Blackhardt's Avatar
    Join Date
    Aug 2006
    Location
    Shiloh NC
    Posts
    133
    My question is does it hurt anything to just take the hode that goes through the back deck off and just let that water go overboard sideways without blocking the tube off completely?

  9. #9
    DAGO RACING CREW 97GPSLEEPER's Avatar
    Join Date
    Apr 2006
    Location
    Orange, TX
    Posts
    4,228
    +1
    169
    It does not hurt anything unless someone is riding behind you on your right side, it will spray them.

  10. #10
    Darthraider's Avatar
    Join Date
    Sep 2005
    Location
    Houston TX.
    Posts
    289

    Wink

    It takes HP to pump water, I would plug it or drill an 1/8 hole in a ss set screw and screw it in the deck outlet.

    Also how would you feel about that 3/8 tubing sticking below your rideplate, at any angle? Drag is drag. and it is multipled with velocity,
    Last edited by Darthraider; 01-17-2007 at 04:25 PM.

Page 1 of 2 1 2 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Replies: 10
    Last Post: 05-06-2012, 09:18 PM
  2. Gains from removing resonator
    By Jean-Paul in forum 4-Tec Performance
    Replies: 1
    Last Post: 04-28-2010, 08:16 AM
  3. Blocking off visibility spout & siphon bilge tube.
    By Pale Rider in forum Yamaha How To & FAQs
    Replies: 17
    Last Post: 01-11-2009, 08:16 PM
  4. RPM gain from better air intake?
    By Vern in forum 4-Tec Performance
    Replies: 6
    Last Post: 07-07-2006, 08:00 AM
  5. Is it worth going from Normal OPAS block off to Pro OPAS ?
    By rxp_boy in forum 4-Tec Performance
    Replies: 12
    Last Post: 11-01-2005, 09:18 PM

Posting Permissions

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