Hello out there, i have recently purchased a 1995 Tracker pro jet 18, with a 90 hp jet inboard/outboard. runs fine. except only about 20mph. and only hits about 4000 Rpms. but yesterday it jumped to 5000 Rpm almost jumped out of the water doing over 30mph which is what i was told is about Factory , but only did this for about 30 seconds and then back to about 4100 Rpm and was doing a slight surge, . I am not used to jet motors being from so. illinois . only propellers .but boat is in good shape and starts everytime. and paid 3000 dollars so i could not pass it up. would anyone be able to help me on what i have got or at least where to start. Is one cylinder not producing. are the carbs not timed together or is the throttle linkage just not adjusted all the way . Note: before we bought it The fishin hole in st louis rebuilt the Carburaters. any help is good help