The 140 FZ was a good engine, but marketing dictates new product all the time, so it was replaced with the 140L. The L made more power but was harder to operate. The 140FZ shares the same plumbing as the L, which is somewhat more complex than the current 140 Sport and your 110. Bear in mind that any YS 140 is larger in both size and weight than your 110.

If you feel that the price is right, and it truly is a new engine and never run, I would buy it. Remember that if it has sat idle since new (maybe 7 or 8 years) it could require servicing before it will run properly due to deterioration of the assembly oil which may cause regulator issues. You won't know until you try running it.