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    My name is Sean and I am addicted to STXs smokeysevin's Avatar
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    May 2008

    STX12F STX15F Budget exhaust

    There seems to be a lot of interest in a cheaper free flow exhaust so instead of answering all of the questions individually I would make an informative how to guide


    2.5 inch aluminum 180 degree U bend


    Flat head screw driver
    small bottle jack
    dish soap (not needed but it helps get the pipe on)

    Time 30 minutes to an hour

    1) Remove the seat, both sections if your ski has the 2 piece seat

    2) Disconnect the battery terminals and remove the battery be careful not to lose the battery hardware

    3) Loosen the hose clamp on the primary waterbox that connects to the secondary waterbox.

    3.5) Loosen both the hose clamps on the secondary waterbox.

    4) Remove the exhaust hose that connects the primamry waterbox to the secondary waterbox and disconnect the other exhaust hose from the secondary waterbox while leaving it connected to the stock exhaust exit.

    5) Disconnect the strap holding the secondary waterbox

    6) Inside hull remove foam padding under front of secondary muffler (right water box). Remove rubber padding between muffler and hull (3 pieces total). Move muffler forward and up onto lower ledge of battery tray.

    7) At the battery tray just in front of waterbox place a small bottle jack approximately 1” from end of the secondary waterbox. Expand the jack until it is suspended between top deck and battery tray. (It will creak and moan just go slowly and take your time) watch where you put the jack there are wires and the steering cable near it, you do not want to crush these.

    8 ) Slowly expand bottle jack to allow room for the secondary waterbox to move forward and up on to the upper ledge of battery tray. Once the waterbox clears upper ledge of battery tray retract bottle jack allowing top deck to rest on top of waterbox.

    9) Move bottle jack forward approximately 2-3/4” (3-3/4” from end of the waterbox) and expand until it is suspended between top deck and battery tray

    10) Slowly expand bottle jack until the waterbox is loose. While rotating waterbox pull forward and upwards to remove. Once waterbox is clear retract bottle jack completely and remove from hull.

    11) Now take the aluminum U bend and install it onto the loose end of the exhaust pipe connected to the factory exit. Place all 3 of the hose clamps on the tube so you don’t forget them later.

    12) Connect the other end of the U bend to the factory exhaust pipe you removed earlier and reattach the exhaust hose to the primary waterbox. Tighten all hose clamps.


    13) Reconnect the battery and secure it with the factory straps.


    This modification costs around $30 depending on where you get the pipe from and it really makes the ski sound great. If you wish to you can mod the primary waterbox but it isn’t required.

    I didnt have pictures so I got them from the riva supercharger instruction manual found here

    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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