Since you are planning to leave within 2-6 months for Colorado you obviously don't have time to build any sort of home business that would take time to get rolling or have longish term obligations. Pizza delivery was a good idea. I'll throw out some others off the top of my head.
Since it seems you are mechanically capable you could do day-work for farmers/ranchers on the weekends, assuming you are in an agriculture based area. They are always looking for good help, hard to find these days. You would have to be proactive about searching since it's usually just a word of mouth type thing. Something always needs to be done on a farm/ranch and the owner can create a job for you to do if he is so inclined.
While you are searching for other options, you could scrap metal on weekends, I did it for extra cash in summer while in HS. Most people in the country have a bunch of junk they need to get rid of. Usually you get "unprepared scrap" steel that pays $180 or so per ton. Occasionally you will get a lucky find of brass or copper that pay better. A quick google search found this
http://recraigslist.com/2013/10/how-to-make-money-selling-scrap-metal/
Craigslist and word of mouth is the best way to find it.
I'll come back later if I think of anything else.