I have pair of 2003 525 with 250 hrs on them.Merc says to replace valve springs at those hours.Do you do complete valve job our just replace the springs. Thanks

If they are off the engine and all the valves will hold solvent poured into the combustion chamber for more than 10 minutes then springs should suffice. If solvent leaks quickly past a valve it might be a good idea to have them cleaned up and or cut.

Both engines are still in boat.

Oh, well then do leakdowns and if they are around 90 or less just do the springs.