Wow how about instead of criticizing it would be nice to see comments that point out mistakes & give advice. Give him some credit for trying. Most of us learn from our mistakes & appreciate any help we can get from others, that's how we learn to do it right.

So, long story short, I read 10 years old Threads online, watched a lot of rebuilding engine videos, download info about my small engine, tear down apart my engine thinking the piston rings were the problem, and no, thanks man. It's the valves

Just done one of these....to refit the springs I compressed the spring in a vice and held them in that position with two small tie wraps....put the caps on with snipe nose pliers then cut the tie wraps with snips...releasing tension....easy Peesy.....😂

If the valve is not out to much you can file it in there and not have to remove head OR spring. Just lift the spring up with a big screw driver to get a small file in.

Thank you for taking the time to video this. I’m having a timing issue with a lawnmower (horrible snap back on the recoil). There’s plenty of videos on how to adjust OHV but none of the older automotive types that I could find. Much appreciated!

Can’t beat the old flat head but harder to keep value adjusted for most folks and they just junk them
Scared of learning how to fix it

Nice job, that seal is the head gasket.  Also that air filter is a crankcase breather.  It vents the crank case kind of like a pcv valve.  (Positive crankcase ventilation.).  Good job setting your valve stem clearance.

Really appreciate this video.   Not many on YT to see for a novice like me.  Going to give this a try; understand 1/4” from TDC and liked the one guys comment about not needing to remove the head; just file in place with thin file.  Getting 18psi on a 12hp B&S.  Took a long time to start, now won’t start so gotta try something.

You just got to it on time as the valve seat will burn , your compression will be poor as well look at the soot as the engine is not running effeciently , its a good time to grind the seats with some paste  to give it nice clean seats , also if you have a bench grinder it will remove sight amouts off the stem just to get your twelve thou for the exhaust valve clearence as its imperitive to have the proper clearence for proper engine running and tuning , thanks alot for your video its good for folk to see whats going on in the engine , all the best Post 10  and happy christmas folks

My dad worked on lawn mowers about all his life and I seen him hold a valve shaft up with screw driver and use a file in there to take off so the valve closes properly.You did a great job.You are a smart guy.Wish I could do all the stuff you do.Plus you have such a good personality wow.

Although you may have a leaky valve, it is normal for the exhaust valve to start to open at bottom dead center. You should be inspecting the valves at top dead center.

LOL, just did this today on an old B/S from the 80s. Put it back together and now I have a self-propelled brush hog that I got for free out of the garbage!
Interesting to see the "drainage guy" doing the same thing I just got done doing.

Cheers man 👍 I was wondering Where to get in to the valves on that kind of engine because I've got more experience with 2 stroke engines than 4 stroke other than car's that usually have ohc engines and now I know 👍💚💛❤️

The exaust opening a little like that is by design to make it easier to pull over from my understanding. That's why you can't get a proper compression reading on these engines.

Every helpful I'm about to try the same thing with my engine thanks for taking the time out to share

The part you called the air filter is actually the breather/PCV

This is also a good time to lap the valves. Easy to do and the tool and lapping compound are pretty cheap.

It will also BURN either exhaust or intake valves  if it runs long enough like that. It doesn't take very long on the exhaust side.

Very helpful. Thank you.

Why did you reinstall the spring couldn't you just push down on the valve with your finger while you check the clearance.😊 This is considered constructive criticism
I want to be watching your video if I didn't think it was interesting it's very informative and I thank you