Okay..23 footer with a Yamaha 5 liter. Supposedly a marinized Chevy small block from what I was told. Starts and runs great up to 3600 Revs, 34 mph or so..push beyond 3600 - sounds like loses power, revs down, but never stalls, then revs up..speed climbs slowly but 7-9 mph off last years top and just sounds weak. If you take the load off the engine - out of gear on the water - you can easily climb over 4400 Revs, and she sounds great - no issues at all.. Tune-up done - month ago before the season - mechanic said sounded like fuel issue - Suggested and I used a water absorber. Used on two tanks of gas - no improvement
Have run two tanks of gas through - emptied water fuel separator 4 times..last time was today and water at bottom of clear plastic cup I dumped it into looked rustier than the others when it settled, plus a few rusty pieces the size of pencil lead. Would think that between the water absorber, and the 4 fuel water seps, the gas would not be the issue - maybe I'm wrong.
Final symptom - may or may not be related - the throttle sometimes is very loose before starting. other times it can be very tight. Doesn't seem to be a rhyme or a reason..not sure if it matters but I threw that in..
Anyone know if there is an inline fuel filter that may have crap in it that I am missing ? Tried to follow the fuel line out of the separator but it gets a bit jumbled plus I'd think that the filter would be in plain view or at least easy to find unless I'm just missing it
Any other ideas ? Secondaries ? Carb problem ? Choke flaps ? Just trying to get an idea where to start..
Thanx - Mrkoj