It is time to replace the 24 year old Evinrude Sailmaster (4hp). A worthy engine that still fires up after the first pull or two. But it would be nice to have a reverse gear and here in CA (and other parts of the world i am sure) you cannot take 2-stroke motors on some wonderful lakes and Lake Tahoe, in particular, is calling my name! So here's the deal. I own an M17 and the current 4hp has been enough power for me. Should i stay with 4 or move up to 5? And here's the biggie... what brand? I think it's Nissan that has the internal tank. Do others? Should i install an outboard motor mount or mount it on the transom cut-out as i have done with the Sailmaster? Inquiring minds want to know... and i have to make this purchase before my wife finds the money and buys something frivolous like food or clothing! Jeff