Upgrading my Coleman Bt200x minibike

[hickory n Steel]

I found my original gas cap so now I have a spare.
I also discovered that it wasn't my fault I lost the gas cap, it turns out the kill switch ground nut was loose ( came off on the way home today ) and since that nut attaches to one of the tank mounting studs Thomas tank was loose rattling the gas cap loose.
I guess it maybe was my fault for not regularly checking to ensure all the fasteners are tight.

I had an appropriate nut, in fact I had two so I added the 2nd one as a lock nut.
If I find a lock washer in my Bucket- o -stuff  I'll put it between the two.

[hickory n Steel]

The new gas cap doesn't really fit right, but that's fine since I found the old one.
It turns out the gasket in the old one was bad though which was probably the biggest cause of it coming off.
I was loosing gas out the cap and didn't think it was the cap because it was even doing it with the new one.
I tried everything I could think of to no avail, then I decided to try swapping gaskets and that did the trick.
I guess the new one just didn't seal because the fit wasn't great, but the gasket is a little thicker than the original on top of being good of course.
In the process I adjusted the carb a bit and eliminated some of the major vibration at idle, I'm not sure if I've got the fuel / air ratio where it should be but nothing I've done has effected how it runs so I may not have anything to worry about there.