Chris Carson Marine is my go to guy. He told me to do it. My local Mercury mechanic told me to do it.
If the shaft fails, the oil delivery fails and ya' fucked.
I used to worry every time I took out the boat. I used to get sick treading all the posts about blown Mercury motors due to the oil injection system failing.
Not anymore.
I'm care free with tanned buns!
It's up to you.
Best decision of my boating life (second best - Nauticus Auto Tab upgrade from my stupidly expensice Lenco electric tabs; and third best - new composite reeds and crankcase stuffers from Chris Carson marine (engine is smoother and NOTICEABLY more powerful)).
Michael
Call me anytime.
702.336.4552