while this invention is susceptible of embodiment in many different forms , there is shown in the drawings , and will be described herein in detail , specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated . i will explain my invention with reference to jet boats from the yamaha motor corporation . however , it should be understood this invention can be used for other boat types ( jet boats , stern drive boats , etc .) that use two throttle levers . jet boats that are commercially available from yamaha motor corp . typically have two engines and two throttle levers . each lever controls one engine individually . this makes it very difficult for the driver to keep both engines synchronized at all speed ranges . the existing and preinstalled lever assembly on yamaha boats ( but also other boat manufactures ) does not provide for any means to synchronize both levers and “ lock ” them so they act as one . this would allow the driver to keep both engines at the same or nearly the same rpm &# 39 ; s , which can be desired in many driving situations . fig1 shows a dual throttle lever assembly 10 mounted in a cockpit 12 of a powerboat 14 . typically , the dual throttle lever assembly 10 is mounted in close proximity to a steering mechanism such as the steering wheel 16 so that a person operating the power boat can control the speed and direction of the boat simultaneously . the dual throttle lever assembly 10 has a first arm 18 and a second arm 19 that independently control the flow of fuel to separate engines and are generally “ l ” shaped having a first leg 20 and a second leg 22 . in a preferred form of the invention , the first arm and second arm , when each arm is in a neutral position , or equally displaced from the neutral position , extend toward the other along the same axis and are generally collinear with a gap 24 separating distal ends 26 of each of the arms . the farther the first and second arms are displaced from a neutral position the higher the flow rate of fuel to their respective engines and the higher the revolutions of the engine and , when in gear , the higher the speed of the boat . fig2 shows a first preferred form of a dual throttle synchronizing assembly 30 for mounting to the dual throttle lever control assembly 10 . the synchronizing assembly 30 has two housings 32 and 34 each of which define a generally “ l ” shaped chamber 36 for receiving arms 18 and 19 respectively . the housings 32 and 34 can be formed as a unitary part or from multiple parts that are , for example , fastened together about the control levers using fasteners , or snap - fit about the control levers or a combination of the two , or any other suitable means known to those of skill in the art . in a preferred form of the invention , the synchronizing assembly 30 is removably attached to the control levers as is shown in fig1 . the first housing 32 has a synchronizing pin 38 mounted within the chamber 36 to allow for reciprocating translational movement between a first position where the housings 32 and 34 , and their corresponding arms 18 and 19 , can be independently operated ( fig2 ), to a second position where the housings and levers are coupled together for dual or simultaneous control ( fig3 and 11 ). in a preferred form of the invention , the synchronizing pin 38 will have a grasping flange 40 , a bolt 42 and a wall 44 connecting the two ( see fig8 and 9 ). the bolt 42 is mounted in a first slot 50 of the first housing 32 and the grasping flange 40 extends outward from the first housing where it can be manipulated by an operator of the boat . a second slot 52 is positioned in the second housing 34 and is dimensioned to receive a portion of the bolt 42 as shown in fig6 when the synchronizing pin is in the second or locked position . each of the slots 50 , 52 have a bottom wall surface 54 , an upper wall surface 55 and a groove 56 through the wall 54 . the vertical distance between the bottom and top wall surfaces 54 , 55 is slightly greater than the thickness of the bolt 42 to allow for smooth sliding of the synchronizing pin 38 . the groove 56 provides a guide that engages a portion of the wall 44 of the synchronizing pin 38 . the groove 56 terminates in an end wall 58 that engages the synchronizing pin 38 to prevent it from sliding out from the first housing 32 . in a preferred form of the invention , a steel spring and steel ball assembly 60 is positioned in a bore provided on the bolt 42 ( fig6 ). the ball 60 is biased upward by the spring to engage the top wall surface 55 of the first slot . detents 68 are provided in the top wall surface 55 at two horizontally spaced locations . the detents are shown to have a generally triangular shape , but other shapes such as round , oval or polygonal ; could be used without departing from the scope of the present invention . when the synchronizing pin 38 is in a fully retracted , disengaged condition , the ball 60 is positioned within the first detent and provides resistance from further inadvertent movement of the synchronizing pin that may otherwise occur from , for example , movement of the boat or vibration of the engine , and until acted upon by the operator . similarly , when in a fully extended , engaged condition , the ball locks into the second detent and provides resistance against further inadvertent movement of the synchronizing pin until acted on by the operator . fig2 - 4 show housings 32 and 34 that are formed from a first portion 70 that defines the “ l ” shaped chamber and a bottom wall 72 that is removably attached to the first portion 70 . the bottom wall 72 a of housing 32 differs from bottom wall 72 b as bottom wall 72 a provides the groove 56 . to mount the housing 32 to the left arm 18 , the first portion 70 is placed over the arm , the synchronizing pin is positioned in the groove 56 and the bottom wall 72 is attached to the first portion 70 by any suitable means such as snap fitting or by threaded fasteners or the like ( fig1 ). fig5 - 7 show a second embodiment where the first and second housings 32 , 34 are each formed from mirror - image half assemblies . the two half - assemblies have a main body portion 80 and an end cap portion 82 that are snap fit together . the first half and second half - assemblies are positioned on opposite sides of the control lever to capture the lever and connected together by snap fitting or by threaded fasteners to releasably connect the assembly to the control lever . of course , when assembling the first housing 32 one must insert the synchronizing pin into position prior to connecting the first half assembly to the second half assembly . snap features 84 and 86 and alignment fins 88 and 90 are provided in a preferred form of the invention to ensure proper engagement of the parts . it is also contemplated replacing this four piece assembly with an assembly having from two parts to more than four parts . fig8 and 9 show preferred forms a , b , c , d of the synchronizing pin . different pin designs are preferred to allow for a well achieved ergonomic feel to the end user of this invention . other shapes and design are possible to provide best performance of this invention . fig1 and 11 show a bore 85 which is positioned through a wall of each of the housings 32 and 34 which accommodates a threaded fastener for threaded engagement to a threaded hole on each of the lever arms 18 and 19 ( not shown ). the parts of this invention are generally formed from polymeric materials using techniques such as injection molding . suitable polymeric materials include polyolefins , polyamides , polyesters , pvc , polycarbonates , abs , aas and the like . suitable polyolefins include homopolymers , copolymers , terpolymers from alpha - olefins having from two to eight carbon atoms . suitable copolymers include ethylene and propylene with monomers selected from these alpha - olefins , excluding of course those having the same number of carbon atoms . from the foregoing , it will be observed that numerous variations and modifications may be affected without departing from the spirit and scope of this invention . it is to be understood that no limitation with respect to the specific device illustrated herein is intended or should be inferred .