Originally Posted by skiknox
Boat was need to me last summer and only pushed it to 4000 with stock 13x13 oj. Could it be trottle cable ?
Pop off the air cleaner and push the throttle all the way open and you should see the throttle butterflies at perpendicular (90 degrees) or nearly so.
My first guess on an LT1 not getting full power would be fuel pressure. The pump intake screen on the rear passenger side of the motor
tends to clog up if you don't have an inline filter installed before the pump. If the intake screen clogs bad enough it wipes out the pump and you get low fuel pressure. Check the throttle opening and the fuel pressure and if they are good you need to start looking at tps,fuel pressure regulator,clogged injector, ignition,compression etc. Fuel pressure is easily checked at the port on top of the motor. There are a bunch of youtube videos on how to check LT-1 fuel pressure and the indmar lt-1 is the same. Depending on load my 97 205 with the LT-1 pushes at least 45 mph and 4500 rpm on a stock 13x13 prop and the 1 to 1 transmission.