i have owned boat for 3 yrs. it will not take off half the time,will act like it runs out of gas.one repair shop overhauled carb,one repair shop overhauled carbs and put more new plugs in it and last shop put new fuel pump and more plugs,still same problem. all shops say compression good,timing good advance good.also the engine has always felt like it has a miss to it at idle,if you get it going it runs fine except when you come down to idle and go to take off. it has a hard jump in the idle like a dead cylinder at idle./have checked compression 8-12-02 and top 2 cylinders have 145 bottom two have 135. have taken carb and plates off and looked at plates and all appears normal. help anyone 