If your process worked OK on the exhaust valve, it should work exactly the same on the intake valve. I'm a little concerned that you said no matter how much you turn the adjustment nut, that it doesn't make any difference. That might imply a stripped nut or perhaps the rocker stud in the middle of the rocker, has loosened or pulled out. Check that to be sure.
Also, examine both valves to be sure that all the parts are present in both. Observe the valve actions by rolling the engine over by hand. Sometimes you can see what is wrong by comparing the actions of both valves in slow motion.
I might suggest that if you haven't already, you search YouTube for "small engine valve adjustment" videos just to confirm that what you are seeing and doing is the suggested process.
Sorry you are having these issues, I know it can be frustrating, but there IS an explanation. Just a matter of careful review of your engine's parts to see what might be wrong.
Yea the video I watched is how I found out how to do it.
Its someone on here who has it up but I forgot his name, its a real simple procedure on the video and is anyway as long as everything works.