Ok so I bought an in-line tester hooked the long end into the boot, the other end to the spark plug seated in the cultivator. I could not see any light or anything from the tester. So does this mean I need something like this? When I did pull the plug it was wet and smelled of gas.
http://www.boxstoreparts.com/Stihl-Ignition-Module-Coil-4140-400-1308-4140-400-1308.htm
The "Wet" plug should indicate that you Are getting fuel to the piston, so Ignition is the most likely culprit. The picture you posted is the coil, and at a reasonable price. Since you say you felt a "jolt" when you held the plug wire, you might try the tester you bought on another motor...lawnmower, etc., to make sure you didn't buy a defective tester. If the tester checks out ok, and you still get no light, then the coil is a good bet. However, I would still check the position of the flywheel on the crankshaft...those flywheel keys do break....and while you are there hold a metal feeler gauge or small screwdriver near the flywheel magnet to see that it still has good "magnetism", and attracts metal strongly. If the flywheel checks out ok, then the coil is your best bet. Oh, and one more thing....you could have a bad "Start/Stop switch, which is shorted such that you are on "stop" all the time. There is a wire on the side of the coil which comes from the switch, and you can remove that wire to see if the switch is shorting out the coil, and keeping you in Stop mode.
Another tip on small Stihl engines....they do tend to "flood" quickly. I have the MM55, two Stihl trimmers, and two Stihl chainsaws, and they All flood easily. After sitting for some time, I have found that I can only pull the rope once or twice at full choke, then release the choke to get the engine to start with one or two more pulls. If I leave the choke on for more than two pulls, I usually wind up flooding the engine, then I have to pull the plug and let the engine "air out" before trying again.
That's about all I can think of...If none of this helps, you may have to take this rascal to a shop, and let someone who does this for a living, take a look at it.