As for riding a scooter - I could care less - it has two wheels and that's all that matters - more power to you for doing it on something unusual!
Re more power:
There is up to a 40% loss of power at altitude that is NOT recoverable, (depending on the altitude of course.)
First understnad the problem - there is a lot less air, therefore the engine is running very rich. So you have to lean out the carburetion.
Standard things to do for high altitudes:
In order to ensure you have the max amount of air getting into the engine in the first place, make sure the air cleaner is very clean, even remove it if needed - just don't do any dirt roading.
Put in smaller jets/lower the needle in the slide. Since on a 50 you will be at full throttle all the time, just a smaller main jet is all you need. Bigger engines benefit from lowering the needle a notch or two in the slide.
And that's about all you can do. Be VERY sure you reverse the changes BEFORE you get to a lower altitude or you WILL destroy the piston and cylinder. Take note of the altitude you had to change settings at and switch at about the same point, or as soon as you notice an increase in power.
For Panama to SA see the shipping section - loads of info there, link on left.
Basically you have to fly the bike and you to SA from Panama. No big deal. DON'T try to save money and ship it. You won't, and you could end up in big trouble with smugglers.
As for Colombia, there is lots of info here on Colombia and safety. A search will find tons of info.
Also, have you thought about doing a blog of your trip? See the Travellers Stories pages - link on left - about having your own page here on HU.
------------------
Grant Johnson
Seek, and ye shall find.
------------------------
One world, Two wheels.
www.HorizonsUnlimited.com