Although your explanation is perfect. The saying has always been that loose valves are better than tight valves because tight valves can be bent due to excess forces and loose valves are less detrimental.

I believe every person on earth needs teachers like you. Imagine if everyone had someone like you to explain situations explained on multiple levels. I now understand the motions, use and how valves may present themselves working and or not. Thank you

This is really nicely explained. Many people have no idea what is going on inside their four stroke engine. I love the model.

Great job, with good model demonstration!... except for a few mistakes if you don't mind them being noted... But first, the main reason to limit valve lash is because a valve with excessively loose clearances will not be pushed open far enough by the cam to flow the amount of air required for full power. The result would be the same if the cam lobes were worn down. Now for the mistakes. While you did admit that tight valve clearances will prevent the valve from sealing properly at the seat, you said at 4:58 that it will "not create any damage to the motor." Wrong. Tight valves are far more damaging than loose valves because the seats will quickly become burned and ruined due to being held open during combustion (especially in diesels). The hot gasses pass through the gap, overheat and erode the seats. On the flip side, at 7:20, you said that a valve that is only "resting on its seat" in the head and not on the cam, is a problem. You said that the springs will place all their force into pulling the valve into its seat, and this will cause the valve and seat to wear prematurely. Sorry, but this is completely false. The springs pulling the valve into its seat completely every time it closes, is the only way a valve system can work properly. The valve and seat wear is part of the design. OEM's have found that if they make the valves too hard so they don't wear, they just break. Intake valves are normally softer than exhaust valves though, so the intake valves will sink into the head sooner and the intake lash will the first to get too tight. Having "a loose gap" as you say, is not one of the worst things for your engine and it will not increase valve and seat wear. The only thing you can do to prevent valve wear is to make sure your thermostat is working ok and at the highest temp range allowed by the OEM. This will keep heat levels up and dissipate carbon. Carbon is what wears out the valve guides, which in turn causes premature valve and seat wear, because the valves wobble around at odd angles in the seat. Yes, loose tappets are what makes that rattling noise under deacceleration and this needs to be corrected by adjusting the valves, but it is not as bad as tight valves. Loose tappet noise should not be confused with detonation rattle which will be during acceleration. Next, you reiterate the whole flawed theory of the cam needing to contact the tappet at all times by referencing a very small problem and making it out to be a large problem; that is, valve lash causing tappet and valve stem wear from the bucket being too loose. Yes it is true that valve components are more easily harmed by excessive valve lash and the hammering effect of any bucket movement beyond clearance spec, but the fact is, that there must always be some movement there. In other words, the wear you mentioned is always happening even when the clearances are set to spec. It is just easier for bucket-float to exasperate the hammering effect when the lash is excessive. There will be an increase in the wear rate like a hammer smashing a nail, as you rightly said, but you cannot get rid of that motion or you will have the much worse issue of burnt valve seats from the valve not fully seating. Keep in mind almost all these principles are the same with the the adjustable rocker and push-rod engines as well. Lastly, while it's true that cold engine spec clearances are designed to account for the expanding metallurgy in a hot motor, the gaps are not completely taken up by the temp changes. Some proof that the lash never gets completely tight when hot can be seen in this: many engine manuals list the valve setting specs for a hot engine, as well as a cold engine, and those specs are only slightly different from each other. There is always still plenty of gap, even with a hot engine in operation, so that may simply be another misunderstanding. Also, no one should confuse the above system with hydraulic lifters. They do indeed always place some pressure on the cam or rocker, thus there is no lash clearance and no adjustment needed. However, when the cam profile is not in position to move the valve, the oil pressure in the lifter is never more than the valve spring force. The valve always fully seats in the head properly as mentioned above. Thus the lifter system is just slightly different. Thanks for reading.

Awesome video. Even my 2stroke brain was able to understand that.

So many veteran mechanics have no clue why there needs to be a gap. Thermal expansion. Congrats to you for knowing how valve gaps really work.

You made a good visual representation of why valve clearance checks and adjustments are very important. I hope those that think valve clearance is not important find your video. Valve clearance adjustment is one of the first maintenance items I do on any new to me motorcycle.

Thank you very much for all your videos. I have a hard time comprehending the manual, but your explanations always make sense to me and make working on my bike less intimidating. Thank u again

Thank you for taking the time to do this! I'm in the middle of re-shimming my F4i and this really helped me understand exactly what is happening with the engine and why. Your comment about Honda was spot on! Almost all of mine were tight...

This is an awesome explanation and it helped me to better understand exactly what's going on with valves and shims. The model helped out a lot too! Thanks!

This is absolutely the best explanation on valves I've seen. Thank you!!

Great vid bro! I've been trying to understand this valve stuff. Now I know why I'm hearing the noises I'm hearing. Thanks! 🤙🏿🙏🏿👌🏿

I already knew this, but this video explains it so well that I will recommend it to friends or acquaintances who need to learn. Congratulations!

Thank you! Extremely informative!

Thanks, it makes sense to me and was helpful, appreciate it! It's much easier to understand with visuals like this as well.

HOLY CRAP thank you for explaining this with these descriptions. When my engine gets hot, the engine started ticking LOUDLY. Adjusting the valve clearance did the trick!

Awesome description! Thanks for putting this together and explaining this for us who a visual learners. Brilliant!

I have been looking for so long! so many videos of people trying to explain it but they use actual motorcycle engine in the video. This doesn’t help me understand what is happening. Your model has helped immensely and I have so grateful you took the time to put it all together and explain everything fully. I just bought a honda and like you said, the exhaust valves are too tight. (spec for .011”, it is currently at .004”). I have never replaced a shim before, so I am anxious about doing it. Because of your video, I understand how important it is to have the correct clearances. I look forward to your other videos.

Very well explained. Finally understood what’s happening with my bike. Thanks a bunch.

Awesome! This is the one of the best and very excellent way of demonstration i ever seen like this. You are a genius & i just love it. Well done! I highly appreciate your exceptional ability & thinking this idea behind tappet/valve clearance. Thank you so very much for all this explanation & visualization.

Best Explanation and display so far. i'll do my cbr 250r now. thank you

The best explanation of how valves work I ever came across that I can follow and understand, great job bro

Thank you so much for explaining so clearly. This video is awesome!

Awesome video for explaining what shims do and how it works. I now understand!

The best explanation I've seen on this. Checking my valves!

This was the best visual demonstration I’ve ever seen

Amazing, thank you!

Thank you for making this video. Now I appreciate the necessity of adjustment even more.

Very nice explanation. Thank you so much for putting this together. Makes complete sense.

Such a great video! Thank you so much for passing on this knowledge!!!

This was a great explanation! Thank you!

Perfect explanation, thanks for the video!

Best description of valve clearances I've found. Like the three bears, not too big, not too small, just right.

Epic Video Man! Thanks for taking the time and making the model :)

VERY VERY well explained, that was a great way to explain that. great job

Great video! Thank you for posting. Appreciate your efforts!

A superb and thouroughly explained video - thank you very much. Have a great day.!

Awesome video man, thank you

This is an amazing video, thanks very much for making it!

just explained perfectly. thank you for the efforts ❤

masterful explanation. thank you kindly!!

Thanks for making this. Made it clear as day to me!

Thank you for a really simple clear video. Excellent

That was a great presentation and description of shim function and why taping noice happens. Awesome demonstration

Hats down, this is the best way that you can explain this component on a motorcycle. \m/

you are a fantastic instructor. i have a 1979 gs850 suzuki ..it has some weird part rattle part jangling sound coming from the engine...i am sure it is the valves needing adjustments [shim changing] . but now i realize what all is going on and and the urgency of fixing thie cause of this warning sound. thanks a billion

Amazing explanation. Thank you

Such a great video and visual. Thank you and I wish more people watch this.

Excellent presentation. I understand it much better now. Thanks

Great video. Good info and descriptions!

Brilliant explanation. Thank you!

Thank you! I never understood this until watching your video.

Great Video..... Excellent demonstration!

Thank you, never understood how that worked until now.

Thanks for the explanation, I've had some advice to only change the oil and leave the valves. But today I've checked and aligned my exhaust valve because it was a little tight.

An absolutely superb explaination using a really cool and simple model! Thank you so much! 😎👍

super good informaion! well done thanks!

Fantastic illustration, well-done 👍

Excellent info! Nicely explained!

This is probably the best explanation about valve clearances on the internet :D

Perfect Explaination!!!

God bless u sir. Very well explained! I learned more than what I intended to.. Tq!

Brilliantly explained mate enjoyed it

thank you for sharing this very useful knowledge. i always like to understand how things work before i do adjustments or anything.

Nice job maniac you did a pretty masterful job explaining this all of you kids out there that's never touched a valve in your life pay attention because this is how it actually works.☺👍🔧

Great explanation man, very informative thankyou!!! Subscribed!

Great video.thank you for your time

Thanks Bruh awesome 3d modelling and explanation first class 😎

Great video!! thank you@!

Outstanding explanation!

mulțumesc pentru explicație

Beautifully explained - thanks!

This is the best explanation I've ever got! So - no more questions - whats the difference between 0.15 or 0.25, who cares... If the manufacturer said it has to be IN 0.15 and EX 0.20 it has to be like that! If not - expect motor not starting (this is the best scenario, because it just prevents owner to kill the motor) if gap is too low, or if rattling noise - turn off your bike immediately and make clearence lower!

Nice effort thanks man

Same issue. I corrected mine with proper torqued spark plugs. This fix high engine temperature issue and die with throttle when bike is hot.

👀👂🤛🏾 awesome teaching...I learned valuable information. 🏁🏁🏁🏁

Good explanation and easy to understand,God bless u.

Good job. Thanks for the effort

Great video! Thank you!

Really well explained!!! Thanks!!

Foarte misto explicat!

Brilliant explanation 👍

Wonderful explanation, thank you!

Thanks. All super clear-ances.

Excellent explanation, many thanks 👍

thanks, I've never understood how all that works until I watched your video. nice one. :)

Great explanation! My 2001 honda cbr 600 f4i really needs valve adjustment. Very hard cold starts. Currently 24k miles.

This is amazing!

Veeeery gooood explanation 🙂 Thank you.

Amazing vid mate

Did an awesome job explaining that bravo 🤗

thank you so much for the info.

Great video. One caveat to potentially add is I've read that tight valves can sometimes be a huge problem with exhaust valves, because they get much hotter than intake valves, and dissipate most of their heat when they contact the valve seat, so there's the potential to burn exhaust valves if they don't fully close. Not sure if this happens much on motorcycles or not, but it could be a factor.

the crazy model is great!

Great explanation. Even as someone who knows a bit about this kind of stuff it was very helpful.

THANK YOU.. Well Done.

Great video mate,very well explained 👍

awesome! well explained.

Very nicely done. I am working on a Kawasaki Mule that has very tight valve clearance and very poor compression. I can't wait to see if I can get the old girl to start, once I set the valves back to spec. Thanks for the very clear explanation!

Perfect explanation