I am just going to throw out everything that is going wrong. Sorry so long! I bought the boat in June and have not been able to use it 1 time. Boat is a 2000 21i 350 Mag. Also has had a ECM conversion kit. Fuel Pressure is good, compression is good. The boat is idling at about 1400 rpms in neutral, and when put it gear drops down to around 1100 rpms. The boat seems to go good for around 45 min to an hour and then will start to spit and sputter some when u try to get on the gas. It will never cut off, it just will not take a load and will not go over 3000 rpms. I dont know if that has anything to do with the idle issue?? (bad gas....I have ran 3 cans of sea foam threw 1 full tank) Back to the idle, Maybe too much air? The small hole on top of throttle body under the cap where air sucks in at, If you cover it about 1/2 way with your finger the rpms drop to where they are supposed to be. It does not cut off which makes me think there is air getting in somewhere else or the ICM. The ICM was replaced. Look at the pic (Is it the correct one?? Part number for the correct one??) Throttle body was cleaned as well. There is a really loud air sound on the engine when in neutral but goes away in moving. Could I be missing a muffler on the throttle body? Every sensor has been replaced on this boat, fuel filter is good as well. Will a CPU diagnosis help fix the problem?? Is it something only a computer can fix? Also, I have included a couple pics of the engine. What is missing?? I know I am missing a cover over the top of the engine and a bracket for alot of the wiring? This is how it was when I bought it. Thanks for any help guys!!
