Which engine to repower a 717 Broadmoor?

[mbezzlr]

Hi Guys,

I got a Broadmoor 717 electric start. All stock (actually, the hood says 707 even though it's a 717. Is that normal?). The engine is bad (cylinder wall is destroyed). So, I'm looking to repower it. What engine do you recommend, and what kind of modifications will it need if any?

Thanks!