If you are running a 3 blade currently and not getting the hole shot, you could consider going to a 4 or 5 blade of the same pitch. I would not go lower than a 17 pitch due to danger of over-revving the engine. We boat at 6200' with a 2015 Sport 19...
We went from a 3 blade stainless steel to a five blade stainless steel with one notch lower pitch and noticed quite a bit more power in the hole shot. Part of the reason for the drastic change is our altitude (over 6K, and bought boat at sea level)...
Our owner's manual for a 2015 Merc Alpha One 220hp said first change at 20, as did our dealer. Apparently the break-in period those first 20 hours can let a lot of manufacturing crud out into the system. Better safe than sorry.
They never gave any reason, just said it was common for these things to appear during the first year in particular, that it was surface only, and that it did not mean that more would continue to appear. Hopefully, that is true! This is the only one...
