I see some of the gas guys using square drive at the strut, and a bearing which takes load off the engine bottom end.
I wonder if some of the guys with experience at looking at these stock 260 Zens, with time on them, could chime in?
Does the bottom end take abuse over time, not using a bearing, and what am I looking for in wear patterns?
These motors don't seem to have thrust bearings.
Thanks Tap

I've been using the collet system now for about 8+ years without any signs of excess wear on engine bearings...I really don't think there is anything there to worry about. Granted I don't put as many hours on my boats as some guys, but still, with some of my engines being at least 5 years old without bearing changes, I think that's good enough proof for me.

Square drive has its place pending what your needing out of it ??

Personally out of 7 Active Race class gas boats 3 use square drive and do so for a specific reason each ..

Gas mono, because stinger drive is cartridge type that allows prop shaft, bearing housing, flex ferrel and shaft to be removed as a one piece unit with loosening on a single screw ... really trick !!

MGB Warpath rigger, because felt radio box bulkhead was excessively close to engine collet making tightening collet tough. Had the parts so just rigged it that way.

Scratch Twin Rigger, Because after 3 catastrophic cable failures from prop thrust compressing cable against engine found out a square drive was needed so cable ONLY had to deal with rotational torque and not compression loading too.