We're almost there. The parts look right. If you look around the rim of the flywheel, you should find a little bump of steel that doesn't match the rest. Kind of like a banana stuck to the center tread of a car tire. Take a picture of that part.
All the parts look like what should be in there, so I'm stumped. I still think it's a basic running issue; the fact that it putters over backwards is probably one that should be ignored.
Back to basics. You've cleaned the carb; can you see light through the idle jet?
a random thought that probably shows my lack of knowledge on how these things work, but could it be that the cylinder started in a weird position, causing it to fire backwards and got stuck like that? Another thought being that someone forced it backwards while the engine was running, forcing a backwards rotation on the cylinders. Again, this is probably showing my inexperience with two-stroke motors, but it happens sometimes on a one-stroke.
Why, it's simple. The piston will be forced down after the fuel is ignited, but will not go back up. It is only useful for brief bursts of power.
Maybe, he means, one cylinder. I know, that a model aiplane engine (looks like about 1cc) can be started backwards. In fact, one I have laying around has a feature that makes it not possible to be started backwards. It is also a 2 stroke, but operates like a diesel.
1982 Volkswagen Rabbit 4dr 1.6l diesel (5 speed)
1987 Honda Elite SE50p with drilled out main jet, shaved head, UNI filter
1985 Kawasaki Bayou 185 ATV
1984 Yamaha IT200 enduro
1974 Piaggio/Vespa Ciao moped, pocketbike exhaust.
yea, almost all nitro modle engines run "like" deasels, and they do have a one-way bearing (nice name for it) to prevent them from running backwards, cause it could happen easily with those.
Spark timing isn't adjustable. The little metal tab that you took a pic of passes the pickup and ignites the spark. Since you appear to have the stock parts here timing should be fine.
You could check it with a timing light. I'm guessing, at cranking speeds, advance should be anywhere from 5 to 0 deg BTDC.
Somebody mentioned in an earlier post that reversing the wires on the pickup would advance the timing. I do not think that should make any difference, but just in case have you traced the wiring to the source.