Bigger Powerhead, Merc 650?

[River Rat 01]

Hi, everybody. I've got a 1971 Merc 650,runs<br />great. Someday we're gonna get a bigger boat.<br />Right now it's on a 14ft Shell Lake, and if I<br />do anything with this 650, I've got a 50 hp<br />to put on this one. How big hp can I go and<br />how new in yrs? and still fit under the cowl. Will the carbs work on larger pwrhd?<br />Can I use distributless ignition, w/out a lot of trouble? Thankyou for any help you can<br />give me.<br /><br />River Rat 01