I have a 2004 17-foot bowrider with a 3.0L Volvo Penta stern drive. Since new it has exhibited a slight hesitation when you drop the throttle quickly (e.g., fast hole shot). I recently had an authorized dealer look into this when I had the boat in for a routine oil change. They advised me that my timing was off (about 6 degrees) and that the accelerator pump was flooding the engine under hard acceleration. They adjusted the timing and accelerator pump settings. They claimed that the idle mixture is fixed on my carb (Holley).<br /><br />When I water tested the boat, it ran terribly. I had trouble starting it and my previously small hesitation was now very big, almost stalling the engine. The top speed dropped from 44 MPH to 38 MPH and constant speeds were no longer constant as the boat would "chug" and vary speed slightly up and down when on plane.<br /><br />Annoyed, I took the boat back to the dealer. They had their most seasoned mechanic look at it who has advised me that the carb is faulty and I need a new one (under warranty). This is surprising to me as I always felt the boat ran fine, with the exception of the slight hesitation during acceleration. The dealer suggested that the timing and accelerator pump settings had been tweeked to try to overcome the defective carburator. Does this sound plausible?
