Kicker size and shaft length for 620

So I just purchased my new to me 2009 Ranger 620. I would like to add a kicker. I am mainly a musky fisherman and I primarily cast so it will not be used very much. Is a 8hp kicker enough for my rig or should I just go 9.9? What speeds will either produce? Basically I really only troll a few times a year but I would like an insurance policy if my big motor were to fail that I still have a way home. Also I assume a 20” shaft kicker will work? Any info appreciated, thanks.

9.9 is pretty standard. yamaha 9.9 high thrust is what many run even with a black motor. otherwise 9.9 merc.

There’s a difference in a true trolling motor (being high thrust) vs just rated by horespower. I wouldn’t second guess either size for pushing your boat just fine… but don’t assume on the shaft length. Make sure you get the right one…too short isn’t good for performance, handling or the motor. Either by advice from those running one on a comparable boat, or a dealer you trust. Power tilt and trim and steering options are also to be considered.

You did not say what brand your big motor is? I have had 9.9 and 15hp on back. The advantage of the 15hp merc is a larger charging system. My current rig has a 300 merc with power steering and my 9.9 Bigfoot that I s remote steered, after a couple hours the power steering will drain the battery.

My main motor is a 250 etec HO. Not real concerned about the kicker matching. What shaft size are most running on a 620? I already have a kicker bracket installed on the back