I just use my main for trolling, I sit sideways in the helm seat and can watch my pole, control my speed, see where I am going, and check my sonar. I've been running with a E Tec main for 12 years. My kicker is a Tohatsu 6, its the 20 inch standard length. My prop is just touching the the top of the water when the kicker is in the all the way up position.. If I am motoring thru bigger waves with the kicker, the prop will come out of the water sometimes, but if I went to the 25" long shaft, my prop would be dragging all the time when in the up position. My kicker is mounted to a fixed bracket that is mounted to a C Dory swim platform. Between trolling and crabbing and shrimping my E-T gets a lot of time at idle, bit it also gets run hard a lot. Since I switched from Champion to NKG plugs I haven't has any trouble with fouling or burning out the center electrodes. It is an E-T thing.