Suzuki 2 Strokes

Hello, just put the front sprocket back to standard and noticed the old and new are a bit wobbly on the shaft. I've used both washers (the toothed and tabbed ones) and yes the locking one rotates in the groove and locks behind spline when screwed to the sprocket.
So thats it? I cant see that it would ever come off and I guess the chain helps keep it fixed, just a bit disconcerting having it wobbly!
The shaft spline is a little worn for the front sprocket but the overall method of locking doesnt seem fantastic? Would I be OTT to put two lock washers on and longer screws!?
thanks!
Steve

The front sprocket on those is meant to wobble a bit on the shaft, it helps reduce chain wear by allowing the sprocket to move slightly as the chain tension changes with suspension movement etc. As you point out, the bolts cannot come loose so there's no danger.