I just pulled some springs from an engine that has been sitting for roughly 3 years. I don't think they have been turned over at all in that time. Once we removed them all and placed them on a tray, there were a few that were at least 1/4" shorter than others. I'm sure that they were the ones that were compressed while sitting, but I can't say for sure. It obviously makes sense that they are the ones. These are Crane's that only have about 65 hours of run time. They were set up with about 150 psi on the seat and about 400 over the nose. The ones that were still the same free length lost about 15 psi on the seat and the ones that were 1/4" shorter lost about 30 psi on the seat. What I'm trying to say is that they needed to be changed. For a set of springs, 10* retainers, 10* locks and seals, you are only talking about $350 or so. It's cheap, cheap insurance.
Eddie

Yes to the pre-lubing prior to starting the first time. Taking it to the next level, install a pre-luber and use it prior to ANY start-up.

1/4" shorter!! NO S#@T!! mine are all out and all of them side by side are visually the same height... i might get them pressure tested just to see what the pressure of them are.. most likely im going to replace...

If they are out - just change them and never have any doubt about it. As Mr. Young already posted, the springs he mentioned had no rebound from sitting - if your's rebound to an equal dimension it doesn't mean they will give the same pressures...

Keep your engine happy & healthy and change the springs, retainers and locks and never look back at it - may keep you away from any down time in the boating months