persons of ordinary skill in the art will realize that the following disclosure is illustrative only and not in any way limiting . other embodiments of the invention will readily suggest themselves to such skilled persons having the benefit of this disclosure . in a conventional craft using a conventional jet pump , water enters the suction inlet ( or intake cavity ) of the craft and is forced towards the jet pump . the engine turns a shaft that operates an impeller that pulls water in and forces water towards the rear of the craft . this flow of water propels the craft through the water and provides a means to steer the craft . in the jet pump , the water flows through the impeller into the next cavity ( i . e ., the bearing hub ). the water entering the next cavity is turbulent . in order to propel and steer the craft , the water must be directed and “ straightened .” conventional jet pumps have stator vanes to straighten the flow of water . the water is forced through the stator vanes and out of the craft through the exit nozzle . the present invention is a jet pump tail cone insert . the intention of the jet pump tail cone insert is to enlarge the center diameter of the jet pump bearing hub . this increases pump pressure which results in better efficiency of the pump . the method of installation includes a three - piece design that is retained by the original mounting holes for the bearing end cone . the jet pump tail cone insert is completely removable . the dimensions of the jet pump tail cone insert are specific to each jet pump model . the diameter of the insert increases if the inside diameter of the pump increases . with an increase of horsepower in the motors , the stock pump becomes inefficient which makes a pump modification necessary . the jet pump tail cone insert part allows the customer to utilize the stock pump rather than replacing it with an expensive after - market jet pump . the present invention transforms the inefficient original equipment manufactured ( oem ) pump into a high performance race pump . the hub diameter of the oem pump has been increased , which creates an increase in pump pressure keeping the pump “ loaded ” in rough water conditions . the increased efficiency adds amazing acceleration , improved handling and top speed . referring to fig1 , 2 , 3 , and 4 , an exemplary jet pump tail cone insert 10 is illustrated assembled ( fig1 ) and disassembled ( fig2 , 3 , 4 ). the jet pump tail cone insert 10 is installed within the jet pump 46 , as will be illustrated and described further herein . specifically , fig2 illustrates an exploded perspective view of the jet pump tail cone insert 10 and jet pump 46 disassembled . fig3 is a side view perspective view of the jet pump tail cone insert 10 and jet pump 46 disassembled . fig4 is a cross section of the jet pump tail cone insert 10 and jet pump 46 disassembled taken along line a of fig3 . the jet pump tail cone insert 10 includes a cap 12 , a body 14 and an end member 16 . in one embodiment , the cap 12 has an interior portion 18 opposite an exterior portion 20 . the cap 12 can be hollow or solid . disposed on the exterior portion 20 are grooves 22 having passages 24 that are configured to receive a fastener . the passages 24 extend through the cap 12 to allow a fastener to couple the cap 12 with the body 14 . the cap 12 has an upper portion 26 opposite a lower portion 28 . the upper portion 26 has a peak 30 extending to a wider portion 32 while the upper portion 26 has a smaller diameter than the wider portion 32 . the lower portion 28 is configured to matingly sit within the inside diameter of the body 14 . the cap 12 is attached to the body 14 using fasteners , as explained further herein . although a cone or dome shape is illustrated for the cap 12 , any shape is contemplated , including square , polygon , rounded , and the like . however , a cone shape is preferred since the water will flow over the jet pump tail cone insert 10 to the exit nozzle ( not shown ). the preferred shape is any shape that allows for the flow of water over the jet pump tail cone insert 10 , while providing the necessary change in flow area through the jet pump 46 . several attachment means are contemplated in order to construct the jet pump tail cone insert 10 and hold the separate portions together . the cap 12 can be attached to the body 14 and the end member 16 depending upon the types of jet pumps to which it is installed . in the preferred embodiment , the separate pieces of the jet pump tail cone insert 10 can be coupled together using fasteners such as screws , bolts , latches , nails , pins , and the like . in another embodiment , the separate pieces of the jet pump tail cone insert 10 can be coupled together using an interior locking mechanism such as rivets , snaps , hooks , clamps , and the like . the attachment means utilized is designed so as to not protrude from the surface of the jet pump tail cone insert 10 , in order to have a low flow resistance of water over the jet pump tail cone insert 10 . the body 14 has an interior portion 34 opposite an exterior portion 36 and a lower portion 38 opposite an upper portion 40 . the upper portion 40 is configured to matingly receive the wider portion 32 and the lower portion 28 of the cap 12 . the body 14 has elliptical shaped forks 42 that extend from the lower portion 28 . the forks 42 have a varying thickness and taper dependent upon the draft angle of the pump housing . the thickness of the forks is dependent upon the diameter of the hub portion of the pump housing . although a curved design is illustrated , the forks can be of any shape , as long as the forks can be received by the end member 16 and can fit within the spaces between the stator vanes 48 . the fastener will be disposed through the upper portion 40 through passages 24 of the body 14 . the body 14 has openings 44 configured to receive stator vanes 48 of a jet pump 46 as illustrated in fig2 , 3 , and 4 . the forks 42 are configured to mount about the stator vanes 48 and be in physical contact with the stator vanes 48 . the body 14 surrounds and encompasses a portion of the stator vanes 48 of the pump 46 . the forks 42 are configured to matingly couple to the end member 16 . in another embodiment , the forks 42 are not in physical contact with the stator vanes 48 . the end member 16 has an interior portion 50 opposite an exterior portion 52 and a lower portion 54 opposite an upper portion 56 . the upper portion 56 is configured to matingly receive the forks 42 of the body 14 . the upper portion 56 has openings 58 that are configured to receive the top portion 62 of forks 42 . the end member 16 has partitions 60 that are shaped to matingly couple to the upper portion 62 and lower portions 64 of the forks 42 . the fastener will extend from the top of the partition 60 through passages 24 through to the end member 16 to the bottom portion 54 . the bottom portion 54 of the end member 16 can have a diameter less than or equal to the upper portion 56 , depending upon the size of the jet pump impeller 66 . the end member 16 is matingly coupled to the impeller 66 of the jet pump 46 . the end member 16 is configured to mount about and be in physical contact with the stator vanes 48 . both the body 14 and the end member 16 have a circular shape , although any shape is contemplated including square , polygon , rounded , and the like . however , a circular shape is preferred since the water will flow over the jet pump tail cone insert 10 . in a preferred embodiment , the jet pump tail cone insert 10 can be comprised of three separate parts that are joined together , as described above . it is contemplated that in other designs , more than three separate pieces may be required in order to fulfill the purpose of the jet pump tail cone insert 10 . the cap 12 , the body 14 and the end member 16 matingly couple to each other . the jet pump tail cone insert 10 may not be water tight . however , the jet pump tail cone insert 10 is designed to fit snuggly to the bearing hub and stator vanes in order to prevent the flow of water between the jet pump tail cone insert 10 and the stator vanes . as illustrated in fig2 , 3 , and 4 , the body 14 and the end member 16 are designed to accommodate any number of stator vanes 48 disposed in the jet pump 46 . the end member 16 is configured to fit inside the exterior side 70 of the impeller 66 . the end member 16 can be designed with an insertable lip 68 that fits inside the exterior side 70 of the impeller 66 . other attachment means are contemplated and depend upon the size and type of the jet pump . the end member 16 does not interface with the impeller 66 . the body 14 and the end member 16 are configured to insert around the stator vanes 48 , thus increasing the diameter of the bearing hub 72 . the impeller 66 attaches to the bearing hub 72 via the driveshaft ( or impeller shaft ) 74 . although a jet pump 46 having six stator vanes 48 is illustrated and the jet pump tail cone insert 10 is designed to accommodate this jet pump 46 , the present invention is contemplated for use in jet pumps having from about three stator vanes to about sixteen stator vanes . it is contemplated that the jet pump tail cone insert 10 can be designed by one skilled in the art to accommodate any size and type jet pump , with any number of stator vanes . the jet pump tail cone insert 10 , and accompanying parts described herein , can be comprised on any material that can tolerate the presence of water and the force of the water rushing through the jet pump . some materials include aluminum ( such as 6061 billet aluminum ), stainless steel , plastic , rubber , fiberglass , composite , or a number of other available materials . as long as the finished part retains its structural integrity , there is no specific material that this design is limited to . as with the many material options there are also many manufacturing options as well , such as computer numerical control ( cnc ) machining , sand casting , investment casting , die casting , permanent molding , extruding , injection molding , vacuum forming , and the like . as indicated above , the dimensions of the jet pump tail cone insert 10 are specific to each jet pump model . the diameter of the insert increases if the inside diameter of the jet pump increases . a preferred overall diameter of the jet pump tail cone insert 10 can be about 70 millimeters ( mm ) to about 80 mm , with about 73 mm to about 75 mm preferred . fig5 , 6 , and 7 illustrate the jet pump tail cone insert 10 installed in a jet pump 46 . fig5 illustrates a rear view of the jet pump tail cone insert 10 installed in a jet pump 46 . fig6 is a frontal view of the impeller and jet pump tail cone insert 10 installed in a jet pump 46 fig7 is a cross section of the jet pump tail cone insert 10 installed in a jet pump 46 taken along line b of fig6 . the jet pump tail cone insert 10 is very easily installed in a jet pump 46 . the end member 16 is positioned to physically encompass and couple to the stator vanes 48 in the jet pump 46 . the end member 16 does not physically attach to the impeller 66 . the impeller 66 , and attached end member 16 are disposed onto the drive shaft 74 such that the impeller 66 is physically coupled to the bearing hub 72 of the jet pump 46 . the body 14 is positioned to fit about the stator vanes 48 , physically encompassing the stator vanes 48 , and matingly attaches to the end member 16 . the cap 12 is then matingly coupled to the body 14 . a fastener is threaded through the three pieces ( i . e ., the cap 12 , the body 14 , and the end member 16 ) of the jet pump tail cone insert 10 ; securing the pieces together and holding the jet pump tail cone insert 10 onto the jet pump 46 . by installing the jet pump tail cone insert 10 , the efficiency of the jet pump 46 is increased since the center diameter of the stator vane bearing hub 72 is enlarged . the principle of this is to increase the internal pump pressure which causes the pump to stay “ loaded ” with water for a longer period of time than is possible using only the standard configuration of the bearing hub . in increasing the internal pressure there is an increase in the vacuum effect that the jet pump maintains with the surface of the water . additional benefits are improved handling characteristics due to the personal water craft “ gripping ” the water more effectively . the present invention can be used in any jet propulsion device and is not intended to be limited to personal watercraft . the present invention increases the efficiency of an original equipment pump preventing the need for expensive tooling changes . while the invention has been described with reference to an exemplary embodiment , it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention . in addition , many modifications may be made to adapt a particular situation or material to the teachings without departing from the essential scope thereof . therefore , it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention .