1995 speedster engine swap

[Awesomeghost23]

Situation: I was able to get a 1995 speedster for $800. One engine is bad and the other is questionable. I came across a deal for 2 engines shafts, props and housings Including the control computer for the pair for $1000

The replacements are 711cc off of a 97 speedster.

What issues will I run into, Im worried about cables needing to be replaced differences in line routing etc.
I already plan to purchase the SBT alignment tool to install them properly and I am looking into carb rebuild kits to refresh them.

1) what issues will I run into?
2) are there any more specialty tools needed?
3) what else should I refresh or look at while the engines are out?

 

[Sandman251]

Don't know if the 720's will work with an MPEM designed for a 657x. Don't know if the motor mounts will work. Wondering about shaft length and impeller compatibility. It's an interesting idea, though. I'll follow along. Please post your progress. If it was possible, I think we would see this happening, which I haven't yet. Good luck.

 

[2strokeboy]

What are the current engines that are bad