David, I have a Honda 2 long shaft on the stock mount, so I will defer to others regarding the current (short) Yamaha 2.5 on stock mount. Thought you (and others) might be interested to learn that Yamaha *might* produce a long shaft version of this engine in the near future. When I queried several dealers at this year's Pacific Sail Expo, they indicated that this was one of the most requested changes/additions to the line. One dealer thought it was only a matter of time. We shall see. For my use, the long shaft has proven the better choice, but the short shaft seems to work well for many. Indeed, if you don't sail/motor in areas with big seas, or if you don't often go forward while motoring, the short shaft might be preferable. My Honda does drag in the water on a starboard tack, but I find this an acceptable tradeoff. BTW: My Honda 2 is now completely disassembled, as the shaft seal at the bottom of the case apparently leaked and let water into the crankcase. If I am correct, this should not happen with the newer generation of Honda 2's, as I believe they did away with the water cooled exhaust of my earlier (1997) model (the engine/head is air cooled in all 2hp models, but earlier models pumped water to the top of shaft housing to point where exhaust elbow enters). Fortunately, I caught this early (oil turned 'creamy'), and there is no apparent damage. When/if my Honda does die, I will look seriously at the Yamaha 2.5--especially if they do introduce a long shaft. I have heard that it makes considerably more power than my generation of Honda (that is, more than the 0.5 hp difference would suggest). I too would like to hear from those who have them on M15's. Scott M15 #478 'bebe' PSC Flicka <<I'm considering the Honda 2HP or the Yamaha 2.5HP motors to replace the electric troller on my M15. It has the fixed engine mount and I'm therefore leaning toward the long-shaft Honda, since Yamaha doesn't offer the 2.5 with a long shaft. Is there anyone with a fixed mount on their M15 who has experience with the Yamaha? Is there a cavitation problem in chop or when going forward to raise and lower sails? I've searched the archives, but can't find any info about that. Any ideas? David>>