Thanks,
I am not replacing the engine due to power concerns, although we will be glad for a little more power, as the old one was somewhat underpowered for us. Our 5411 blew a rod, so must be replaced. We are on Lake Erie, so currents have not been a problem. Only considered the M18 after we learned it would be equivalent in size, and supposedly will not require any modifications to install the M18. If you are selling your M-18, please post it on the classified ads, and we might be calling, if we have any more delays getting the one we anticipated.