Nick,
I posted this a while ago for someone else. It may help. Ignore references to decomp if you don't have one and any other comments that don't fit your ped.
Ron
Spark plug. This is the bane of all 2 cycles. Spark plugs can appear to work fine in open air, and never fire in the cylinder. The problem is that air is not as good an insulator as a compressed fuel/air mixture. Often, when the plug tries to fire in the cylinder, the additional resistance of the mixture and the plug being wetted will combine to cause the spark to leak across the surface of the insulator around the center electrode.
Buy another new plug or two. They do not need to be platinum, even if they are not the exact number, if the threaded portion is the same diameter and length, they are fine for testing. Just set the gap to your ped's spec. Each time you have tried to start your ped, take the plug out, if it is not bone dry, wash it with carb or brake clean and blow dry it with compressed air or shake it and set it aside to dry. Replace it with one of your clean, dry plugs. Just for laughs, take any spark plug and gap it at about .030", laying on the head, this should produce a good fat spark. and tell you your spark is good.
You obviously know where the points are. Turn the engine slowly until the points just break contact. Using a pencil through the spark plug hole, make sure the piston is near the top of it's stroke (closest to the plug). If you are ambitious, 1 to 2 mm before top dead center is where the points should break. This does not have to be perfect to run, if it feel like you are near the top of the stroke, this is ok.
Trying to start the ped.
Turn off the gas and drain the carb if it is easy to do, it will save pedalling time. Now, using the decomp to get the engine turning, pedal like hell for way too long. Change the spark plug for a dry one and repeat. When the plug comes out dry, you have pedaled enough.
It is possible that while doing the above, the ped will spontaneaously start. You should be so lucky!
The purpose of the above exersize is to clean all the excess fuel out of the engine. Once a 2 cycle is flooded, you have two problems, the plug gets wet and leaks, and your mixture is not easy to lean out again. The above exersize solves this.
Now, check for spark using the "plug on the head" trick and install a clean, dry plug.
Turn on the gas, set the choke and pull the decomp. Pedal. As soon as the engine turns ok, drop the decomp, keep pedalling and slowly roll on throttle. Any more than 1/4 throttle is too much.
If the ped does not start, immediately turn off the gas, because we do not know if the carb is flooding yet.
Begin again at "Trying to start the ped.", but this time, do not use the choke and make sure that the last plug you use is not the same one.
One of the above methods should at least make some smoke and noise. Post the results.