I have a 2003 Marlin 300 with twin Yamaha F225 4-strokes and I’ve been looking into repowering options. First you have to consider weight and what your hull was designed to handle. Some of my fishing buddy’s repowered their Marlins with Suzuki 250 fly by wire 4-strokes for $35-38k. But their hulls were designed to handle the heavier 4-stroke engines. One of my buddies with an older Marlin designed for the lighter 2-stroke engines had to go with Evenrude G-2’s because they are lighter than 4-strokes and less expensive. Everyone seems to like their Suzuki’s and my buddy likes his G-2’s, but I’ve seen some mixed reviews on G-2’s. The various owner web sites tend to recommend going with 300’s instead of 250’s.