Originally Posted by Rangerz

Fyriza, the go pro records as mp4. I assume you imported the footage inot the go pro studio software which takes the mp4 and converts to avi. I think you may have either skipped the 3rd export step or exported as avi. Avi is uncompressed and is very large. You will want to use the youtube pre set in the software or export as a mpeg2 or .mov file to get the best results.

Youtube accepts a bunch of different codecs the mpeg2 and .mov have worked well for me.
Hope that helps