If the prop is about 6 inches in diameter then it is an .049

I've got an hold one and the tank is full of gunk. You might want to take the tank off and clean it all out. Make sure you oil it well if you clean it with water.

The first step is to attach it to something and try to run it. Normally they have a spring starter such as you see here:

http://www2.towerhobbies.com/cgi-bin...?&I=LXB440&P=7

You'll need some fuel, a big 1.5 battery, and a glow plug clip. Like these:

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXB465
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXL368
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXEPD2

If you can get it to run you could put together a control line model for little money. Might be a good place to start. e.g. :
http://www.sigmfg.com/cgi-bin/dpsmar...FV3.html?E+Sig