Your best bet is to get someone with experience to help you. You can't beat having someone there to show you exactly what does what and how to go about doing it. If you don't belong to a club, then that would be a excellent start. As well as joining the AMA for the insurance.
Back to your engine, what brand and type of glow plug are you using? Most four strokes tend to like the OS four stroke plug. Also, check your fuel. If it's old or been left open, it will absorb water from the air and go bad. Get some new fuel tubing from a hobby shop and replace the old line with the new. And are the lines hooked up right in the fuel tank? Make sure the line with the clunk is the line going to the carb. It's easy to forget which line is which once you put the stopper on the fuel tank.

Jesse