2000 Yamaha 150 hp 2stroke no top end,good compression, good spark, timing right on the money,at idle sprayed fuel down throat of each carb with two plug wires off, each carb bogged like it is supposed too. Ran motor without cowling and flame arrestor, fuel spray thru emulsion tubes looks good and uniform thruout all six cylinders at WOT, but engine wants to race and bog race and bog. Problem starts just before WOT- cam position is about 1/2 before raised knob.<br />Customer had boat for sale - sat in hot sun on a parking lot - August - December, brought back home - sat 6 weeks and now has this running condition. ?