first, why do you want to add a kicker? if for trolling, you'll likely need a min. of a 15HP with a bigger prop to push the boat. i doubt the yami T9.9 would work well (it would be working at near full throttle, not in it's better fuel economy band and even a small 4s engine at high rpm will be noisier than the F225 running 6-800 rpm). When i troll 2-4 mph with one F225, i'm usually 6-800 rpm (900 rpm max) and at that low rpm, the yami fuel mgmt gauge doesn't usually even register the low fuel flow).
are you planning to mount the kicker on the port side area with some kind of mount and bracket?
If the kicker is mounted offset in height and distance from transom than that of the main motors, it'll be very difficult to tie the kicker in to the steering with the main motors. Also with both main engines still down and not working in conjuction with the kicker to steer, the steering ability of the kicker will be greatly reduced especially if wind and currents are involved.
i had a campion 622 with O/B and a T9.9 kicker on a tilt bracket and tried to tie the kicker and main together to steer together, but the only decent (but ugly) solution was the EZ-steer which the tie bar would need to be constantly removed when kicker was up and not in use. Needless to say, i avoided the ez-steer and operated the kicker as a tiller.
i'm assuming a 2004 boat has F225's. I would avoid kicker all together.
aesthetically and functionally i don't see it working well.
