Re: Need help!!! Asap!!!
It's possible it came that way from the factory, also on your manual, did it say valve seats or spring seats? The engine will definitely have 2 valve seats which is what the valves close on inside the cylinder, then there's spring seats that the springs sit on outside the cylinder.
It's usually typical practice to have some kind of seat for the springs to sit on when installed on an aluminum head, most the time it's just a really thin washer that sits under the spring to prevent direct contact with the spring and the aluminum and it's put there to prevent abnormal wear. Without it you'd never know the difference and it could run for years trouble free or the spring could start to dig into the aluminum after a few thousand miles.
It's possible it could have left the factory like that and it could run for years undetected but I'd keep asking around to see if anyone else knows more about this. as far as getting replacement parts, these engines are Honda clones so maybe look at a Honda small engine service catalog or look for some online shops that sell small engine parts since these engines are fairly common and the Honda parts should fit them.