yamaha lists the 4HP as weighting 60lbs (short shaft model). maybe a couple pounds more for the 20" shaft. many folks use the yamaha 4HP on their M17s. reference - http://www.yamaha-motor.com/outboard/products/subcatspecs/5/specs.aspx i was very close to giving up on my suzuki and getting the yamaha 4HP ... but the motor dealer quoted me a nice price on the phone and then changed it when i went to the store. i walked out of the store never to return. the honda 5 is 61 lbs long shaft model. reference - http://marine.honda.com/Products/modeldetail/BF5 suzuki states their 4/6 HP long shaft weights 57lbs. i've not weighted my long shaft 4HP ... but it sure feels like more than 57 lbs! reference - http://www.suzukimarine.com/Product%20Lines/Outboard%20Motors/Products/DF4/2... http://www.suzukimarine.com/Product%20Lines/Outboard%20Motors/Products/DF6/2... to add to stan's (aka, paint boy) comment i know of one Puget Sound M17 that uses a yamaha 2.5HP. the owners have had good success with the motor, and do cruise the san juan islands. the 2.5 yamaha is only available with a short (15") shaft ... think it would be way to short on the older fixed mount (cutout) M17s. :: Dave Scobie :: M17 #375 - SWEET PEA - www.m17-375.webs.com :: Sage Marine