Use a smart level to check the angle of incidence float top to wing bottom. (there are differences in lengths of rear N-struts that can make a big difference in ability to get them out of the water). Any difference? How about the bottom of the horizontal stabilizer to the top of the floats? (saggy tail?)
What do the bottoms look like?
Is one leaking water, not pumping water out?
Look at the lift strut forks- does one plane have them cranked in or out on only one side?
Check how strait the tail is by measuring from the outside of the aileron bay to the outside of the stabilizer on each side, (that is often a speed changer though).
How about the props? Measure the length, and the actual angles of each blade at different stations- how do they compare.
Engines? One making more power than the other? (check exhaust for blockage per A/D?)
Is one running a short mount, the other not?
Just some places to start looking! Have fun:lol:
One more thing to check- float angles- top of each float vs. float on other side, distance variation front of one float to tail of other. Are they parallel and square.
Very small change makes a big difference in them draggy beasts. I ran out of time once so splashed the cub back to the water with the tail of the plane vs tail of floats 1" off to the side. The plane flew 5 mph faster than I ever had!
Last summer they did a part change on wire pulls on the 185, said it was good to go. I brought it back after a couple of landings and asked them to re-set all the rigging on the floats. After a discussion, (pilot vs. mechanic knowledge and linage type
) they decided to at least look at it.
It flew better and faster the next day.
1/2" difference in the square will make a difference. Most planes have been tweaked, floats also, so you might need to experiment to find what works best for that combination.:-? Takes time but worth it in the end.