Thank you for allowing me to assist you, my name is ***** ***** I will be happy to assist you with your concern today.
I will always try to reply back to you right away however please understand that I may be busy answering another customer back and thus it may sometimes take time to reply back to you. As soon as I return I will be sure to reply back to you as soon as I am able to.
For this to happen and yet have it seemingly run perfect otherwise usually indicates a throttle cable issue be it broken, the actual throttle thumb part broke (where cable attach's) or when throttle cable attach's to the throttle body and or throttle body issues and thus those are the very first places to start. The easiest by far will be remove the seat, locate the throttle body and watch the linkage/throttle cable as you press the throttle watch if it moves, if not you know the problem is cable or actual throttle thumb portion. You can disconnect the cable holding by hand and see if it's connected as you work it at each end if both ends don't move together the cable is broke. Know that the cable can also come loose from it's mounting inside the hull but for throttle this usually will not cause complete non functional throttle.
Here is a diagram: http://fiche.worldofpowersports.com/wps/showmodel.asp?Type=13&make=seadoopwc&a=239&b=17&c=0&d=-AIR-INTAKE-SYSTEM
Know that you may need to remove the air box for better visibility of the throttle assembly at the throttle bodies.
I can also supply the entire oem service manual for you which I will send an offer over on including a personal email for future reference and help.
Please rate my answer when ready. Bonuses are appreciated.
If for any reason you are not satisfied please reply back to me for further assistance to which I will be glad to help you. The rating system is only to rate me as an expert not the site or the product. If you have any problems for any reason please reply back and let me know.
Thanks again for using justanswer and have a great day!
If you need any further assistance you can reply back at any time for my help.
I'd be happy to answer any other questions you have even if not related.