We just bought a 2001 Fisher pontoon with a 2001 Mercury 125 on it. I haven't gotten the motor model number yet but I do have a question. The gentleman that I bought the boat from said that at certain RPMs that the outboard would run on 2 cylinders and if you move it up a little it kicks in and would run on all 4. I have only had the chance to get it out once so far but there is a certain RPM range, around 2500 that it runs very smooth and at a nice slower pace. Then if I move the throttle just a very little bit the RPM jumps up to about 3000 and it feels like the other 2 cylinders do kick in and it really picks up power and speed. I have never owned a Mercury motor before and can't seem to find any thing on here about this feature ( if it really is a feature) so is this correct or is there possibly some thing wrong? The boat will cruise very nicely at 3800 to 4000 RPMs and will top out at just under 5000. According to what I found in an online manual the operating range for this motor is from 4750 to 5200 so this seems about right to me. I have also found that there is some water in both of the tubes to add extra weight so once that is resolved I expect to maybe run a little faster, correct?