What is the check valve for?
Edited to add: It is part of the fuel tank system. Part #50. Hopefully they found Part #60, because that piece looks like it could easily get sucked up to the pickup tube and causing a loss of fuel pressure until the engine is shut off.
Only thing I can think of that it might be is the spider pin bolt. If the end that threads into the other side of the carrier had come out, you'd have bigger issues. Heck, getting the rest of the bolt out will be a fun time. A left handed drill bit will be your best bet.
Part 15. Called a...
If using wood, bury the legs for extra support.
I made mine from steel and cement. With just three legs (not buried), it is rock solid.
Adjustable seat heights if you plan for others to use it.
How do you know there is a leak?
Is there a frost hydrant that you use for watering? I'd bet the hydrant is leaking before the actual pipe unless it was poorly installed or in rocky ground.
Stick your ear on the hydrant pipe.
Alright, I'll tell you.
12345678
1(2)3(4)5(6)7(8)
When some asks what your password is, you can tell them 12345678, but you really mean 1-Two, 3-Fours, 5-Sixes, 7-Eights.
I hope I'm spelling it right....
Menthol Camfer is what my mother would go to for any cuts. It come in a 3" or so round tin canister. In fact, she had 2 or 3 different "treatments" in different colored containers.