Hi guys I just wanted to Introduce to you my other Channel "Kirkman's Academy" - which i'm just getting started. It's a go-to channel for simple explanations for hard to grasp subjects such as physics, maths and chemistry etc. Here is the link: www.youtube.com/@kirkmansacademy/videos . Thank you so much for looking, and if these topics interest you then I hope to see you the there. Many thanks indeed. Craig 😊👍
I cant Thank You enough for taking the time to make this video!! I can say that shamefully after roughly 5 hours of my life that I'll never get back trying to adjust the valve clearance on my 2005 Honda Recon ATV, God led me to your video!! What an ABSOLUTE answer to Prayer!! I just could not grasp the understanding of TDC on the "compression" stroke!! I was at my wits end..... I adjusted the valves I dont know how many times, but on the wrong stroke. With the help of your video, I was able to adjust the valves with NO Issues!! Thank you again SO VERY MUCH for the clear and conscise explanation, and the engine prop you used REALLY brought it home!!! Definitely downloading and bookmarking this video :) May The Lord Bless you and your family Brother 🙏
This was the most comprehensive explanation of how valve clearance works. Much appreciated the effort put in to explain for a newbie like myself. Instant subscriber
Just want to say that as your video title states- this is the only video I'll ever need to learn 4 stroke tappet clearance. 100% TRUE!!!!! After watching this video all my doubts and queries are cleared and the explaination with this model , amazing work man. Just AMAZING!!!!! I do hope you make such videos in future as well. And i request everyone to just watch this 11 min video with patience and all your queries will go away. Thank you again for making such simple video explaination.
Great job my friend. I have a 22 year old Peugeot 206 1.4i which has had a persistent misfire (P0200 and P0300) for several months (I have not driven it), I have replaced the sparks, the fuel injectors, the coil pack, the knock sensor, the camshaft sensor, done compression tests, tested the continuity and voltages across the ignition circuit, I have just replace the timing and drive belts (they were old anyway) and all that I have left is the valve clearances...I do get an occasional 'ping' during a misfire so I'm pretty confident it's the valves after watching this video....
What a great detailed explanation of what too loose and too tight valve gap adjustments do! I knew they needed to both be correct, but now I know why and the consequences. For your adjustment procedure, I know this was just for explanation, but you didn't mention loosening the adjustment locking screws before adjustment, tightening them after and double checking that the adjustment did not alter from tightening them enough to make a difference. Potentially, anyone who sees this for the first time could do it wrong and have an issue shortly after. You know I love your work, but I just wanted to point that out, as I'm sure others have as well. I hope you don't get bombarded too badly over it. Mine is meant as a friendly comment. Thanks for the detailed explanation, Mr. Craig. Always so informative, detailed and the arrows really help.
I had a good general idea of how the valve terrain operates, but after watching your video It's clear to me. Great video and very educational. Thanks, mate.
If the exhaust is too loose it will be difficult to start, the comp release won't hold the valve open enough. The compression release is a small tab on the camshaft that holds the ex valve open just a small bit to allow easy starting, when the RPMs reach a certain speed the tab slings out of the way and allows the engine to operate normally, so if the gap is too much the tab will only take up the gap and not hold the valve open.
This is a superb video. I've not seen such good - concise, yet thorough - training since I was learning to be an aircraft technician in the Royal Air Force. Thank you very much, God bless, and let's hope the algorithm pushes this out to many more people. Chris 👍
I bookmarked this video. Emailed it to myself. Texted it to myself. Sent it to my wife's email just in case I manage to lose it. This is gold. Thank you for this OUTSTANDING tutorial.
There aren't many folks like you mate, just aren't. This is a class A rating masterpiece. I won't say much let me enjoy your thread of videos. Hishia, Africa - Zimbabwe.
That was a very good instruction. I would like to add, because I got fooled once, that Briggs and Stratton Vanguard engines in the US call for an indicator stick, and they specify 1/4” lower after TDC on compression as the set point. I’m not sure why, but that’s their spec.
I use a multimeter with a “frequency” function to set idle speed. Put an antenna on the positive input terminal, place the antenna just close enough to the spark plug wire to get a reading, not too close. i.e: 1000 RPM= 16 2/3 RPS, or 17 hertz (rounded up). This assumes a lost spark system, whereas a distributor spark would be half that. Ok last Heloise Hint, don’t want to be a pest, but just to give back a token to repay all I have gleaned from watching your videos.
Great video Craig. I have always wondered why they went to the overhead valves. These engines having more parts seem to have more problems. I have a Techumse flat head on my 1974 Sears Rototiller and I run it every year 5 or 6 times, drain the gas from the carb, and put it away. The flat head seems like a more reliable engine. If you would, compare the flat head to your model here and note the differences between engines. Thanks
First of all, thank you for your kind feedback. I really appreciate it. And yes, you have given me a very good idea for a near future vid. I do have a flat engine somewhere in my pile of engines. I will pick out one and do a vid on the comparison, just as you said. I do have a list of a few vids to get through first but I will get round to then. Thanks again. Craig 👍👍👍
I love my flatheads, FLATHEADS FOREVER. But the OHV engine is better in practically every way possibe. Yes it sucks to admit it but it is no contest. Unfortunalty
Great video, gf was asking questions that i couldn't explain very well. Your concise and thorough video (and that cutaway engine) made everything crystal clear. Thank u kindly sir! Instant sub!
Great job! another great video for , all of us to view. I only wish I would have had those video's when I was 14-15 yrs & just getting into small engines, those video's & your information would have made A World of help for me. Keep them coming.
Thanks for sharing your knowledge! Great video I’m working on a dead 4 wheeler think it jumped time so I’ve been playing with the timing and was getting tdc but wasn’t sure it was on the compression stroke now I do thank you!
Hi! I've been following your channel for a few years now. I do small engine repair work in Lithuania. I'm learning from my father who is an experienced repair specialist. I rely on your videos for the theoretical part of the job as many situations I encounter seem like magic if explained with no theory and only by experience and observations. I couldn't wrap my head around the saying that valves 'burn out' if the clearances are too tight. I have observed it, but couldn't figure out the cause. The same goes for the problems explained in your ignition coil videos. Thank you! Have you got experience working on ridable mowers and their electrical components? I still struggle with troubleshooting that
Excellent. And if the valve gaps are correct and there is still poor compression it means that you have other problems, such as damage to the valves as you describe. (Hope that's not so in my case, but I guess you may have another video covering that :) )
Thank you so much for your generous words! 😄 I'm absolutely delighted to hear that you found my explanation on 4-stroke valving to be the best you've come across. Your appreciation means a lot to me, and I'm here to provide more insights and explanations whenever you need them. Keep that curiosity alive, and I'm grateful for your support! Craig
This is an amazing video. I'm very visual and learning how it all works together while trying to adjust my Ural valves is priceless. Thank you for explaining it so eloquently, easy to understand. Cheers!
How can you til if the valves should be offset when manual shows either or or doesn't say? Like .004 to .008 intake & .006-.008 exhaust. Or mfg manual says .004-.006 inch on both. But doesn't say if it should be offset for a 208cc generator. I only hear offset the valves from the technicians by example of operation. So offset or not?
Great cut away engine! Instead of going for top dead center, I rotate the engine until one valve is completely open (on the top of the cam lobe.) This tells me the other valve is completely closed. I adjust the closed valve, rotate until that one is completely open and adjust the other valve - which is now completely closed. This also takes the compression release mechanism out of the equation because it will not be in place with one valve completely open. I wonder if my practice is sound (it seems to be and seems to work?) So many folks do the TDC on compression thing that I wonder. Thoughts?
First of all, thank you for your kind feedback. I really appreciate it. As for the way you adjust your clearances, I also adjust the clearance this way myself. I too have never had an issue with. I find it just as accurate as the method I showed in the video. I think it’s just a case of preference really, and it seems that the more experienced mechanics among do it the way you mentioned. I think it’s also a generation thing to a degree. When I was taught how to set clearance back in the late 80’s, it seemed to be the old fashioned way of doing it. I have some old Honda engine service manuals and in them is the method you explained. I think it’s just become a little more popular in recent years to adjust them as I showed in the vid. But in my opinion your method is great 👍
you are a genius man i have a bike gs150 and it has 133000km on it my tapped sounds like tik tik and now i adjust tapped according to the theory you present and my bike engine is running smoothly and acceleration like boom on 2nd gear the wheely happens you are genius bro 👍👍👍👍👍👍👍👍👍👍🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹
Great video and explanation; thank you very much. I tried to set the valves on my 250 (OHV motor) and there was no way I could loosen the valve adjusting locking nuts.. They just would not loosen... I was afraid I might strip them... The motor was on the F timing mark and both valves were closed, but even then I could not feel any "looseness" I`ve got no idea why? 😕
Thanks for your teaching. Had no idea how it works. Question: is having the piston to its highest position is what matters to start adjustment. Correct if wrong. Again thanks and Gob Bless.
Thank you so much for your kind comment. I really appreciate it. Is your engine a small single cylinder like this? and could you tell me of any parts of the video that needed more clarification? I really appreciate your honest comments. Thanks again. Craig
That was an amazingly detailed video. I haven’t found it explained better anywhere else. Curious if you think that setting an intake valve .01mm over spec would cause an issue? I know some engines give a range, but my particular one on a motorcycle does not. I had it set to spec and it seems to have tightened prematurely after only 1500 miles causing performance issues. I don’t know if this is a feature of a new engine, or if I should set it slightly looser to extend the time between service. It calls for .08mm and I’m thinking of setting to .09 next time. There isn’t a lot of information about things like this. I would greatly appreciate your or anyone else’s opinion. Thanks.
Hi. First of all, thank you for your really kind and thoughtful feedback. I really appreciate it. Now to answer your question, in my opinion of course, . When it comes to valve clearances, precision is key, as even a small deviation can affect the performance of your engine. Setting your intake valve clearance at 0.01mm over the specified measurement may seem minor, but it can indeed have an impact. However, valves can tighten over time, especially in new engines as they go through a break-in period. This tightening is often due to the valve and seat wearing in and finding their fit, which can cause the clearances to reduce. If you've experienced a premature tightening after only 1500 miles, this could well be a sign of normal settling. Setting the valve clearance to 0.09mm, a slight increase from the specified 0.08mm, could provide a buffer against this premature tightening. However, just be mindful of the potential for increased wear over time, which could lead to a larger than intended clearance if it's set looser from the start. If you feel that you had no issues though and so are comfortable carrying on setting your valves this way then that's absolutely your choice. Every engine is unique and how it wears in can vary, I personally would just keep in mind that regular maintenance and checks are crucial for the longevity and performance of your motorcycle engine. But anyway, thank you for sharing your experience with you motorcycle here. Thank you Craig
@@TheRepairSpecialist I really appreciate you taking the time to respond. I think based on your opinion I’ll chalk it up to extended break in and stick with the spec for now. The issue it was having was that after an hour or so the engine would start to hesitate, sputtering as though it was running out of fuel although it wasn’t. After checking other things I checked the valves. I don’t guess they were more than .005 tight, but it seems that it caused the issue when it got up to full temp. I wouldn’t have thought the tolerances could be so slight. Thanks again.
Thank you! Great explanation indeed. One question though: is my understanding correct that during a one full cycle the magnet on the flywheel passes by ignition coil twice? If so it appears to me that we get on spark at the end of compression and one more on exhaust? I'm not very sure how that works and everybody seems to say there is just one spark, and that is reasonably.
Thank you for kind comment. I really appreciate it. Secondly, you are absolutely correct about the spark firing twice for a full revolution of all four of the engines strokes on these small single cylinder Engines. Other people who have told you they do not fire on the exhaust stroke are confusing themselves with larger engine that use a battery to charge the sparking system to generate the spark. These systems have more advanced spark timing. These small lawnmower engines, however, are not that advanced. They do not use a batter to charge the sparking system. Instead they use the magnet on the flywheel and the ignition coil pack. Every time the magnet passes the coil pack it will generate a spark, as you correctly said. This means that after the magnet has passed on the compression/power stroke, it's one full turn from this will indeed be the exhaust stroke, which is where the spark plug fires again. Why does it do this? Well simply because of the design of the magnets positioning on the flywheel making for a simple and easy functioning sparking system function. Of course, the side effect of this system when it was developed was that the spark plug would fire on the exhaust stroke as well, but this was to NO detriment to the engines function what so ever. On other larger engine types where the spark plug fires on the exhaust stroke, it is known a wasted spark system. Take a google search and search for this: Wasted Spark System. I hope this helps Craig
Excellent video. I wonder if it is safe to use a rope to lock flywheel of lawn mower so that I can remove nut? I saw in one video guy said it is not safe to use piston stop tool on large engines like lawn mowers. Some guys using rope, but some saying could be issues with valves. I have a feeling it should be safe to put a rope in the middle of compression cycle as the both valves will be closed. Am I right?
Hi. In my opinion, using a rope to lock the flywheel of a lawnmower can be a useful method for preventing the engine from rotating while you work on it. However, it's important to use this method correctly to ensure safety and prevent any damage to the engine. Your understanding is correct: When you insert a rope into the spark plug hole and position the piston in the middle of the compression stroke, both valves should be closed. This is a safe position to lock the engine because it prevents any potential interference between the valves and the piston. It's a common practice among mechanics and DIYers for performing maintenance tasks like removing the blade or working on the crankshaft nut. The key is to ensure that the rope is inserted far enough into the cylinder to provide adequate resistance when you turn the crankshaft nut. This resistance effectively "locks" the engine, preventing it from turning while you apply force to loosen or tighten the nut. Using a piston stop tool is another method, but as you mentioned, it may not be suitable for larger engines like lawnmowers. Using a rope is a practical alternative, and as long as you follow the correct procedures and ensure that the rope is properly inserted to stop the piston, it can be a safe and effective way to work on your lawnmower engine. Always exercise caution and follow safety guidelines when working on any machinery, and consult your lawnmower's manual for specific recommendations related to maintenance and repair procedures. Thanks Craig
I always adjusted the valves of my motorcycle myself, but only because it is part of the normal maintenance checks, and never really understanding the underlying reasons. Now I finally have a much better picture of why we sould keep good track of it. However, I wonder why we have to do the adjustment at exactly top dead center, since both valves are completely closed during the whole compression stage. Couldn't we do it at just any point of the compression? Also, I often hear that if the valves are not correctly adjusted, there is a risk of one of them falling inside the cilynder, causing the complete destruction of the engine. How would this happen?
I'm delighted to hear that you found the video on adjusting 4-stroke valve clearances informative and that it provided you with a better understanding of this crucial aspect of motorcycle maintenance. Regarding your questions, let me clarify: Adjusting Valves at Top Dead Center (TDC): Adjusting the valves at top dead center is a common practice because it provides a known reference point where both valves are fully closed during the compression stroke. This makes it easier to set the valve clearances accurately. Working at TDC ensures that you're adjusting the valves when they are in the correct position relative to the camshaft lobes and lifters/tappets. While it might be possible to adjust the valves at other points in the compression stroke, doing so at TDC simplifies the process and minimizes the risk of errors. Risk of Valves Falling into the Cylinder: The concern about valves falling into the cylinder if not correctly adjusted typically applies to older engines with certain design characteristics, such as non-interference and interference engines. Non-interference engines: In these engines, the piston and valves have no overlap, meaning they cannot physically collide even if the valve clearances are significantly off. Adjusting the valves in such engines might not result in catastrophic engine damage, but it can lead to poor performance. Interference engines: In contrast, interference engines have piston and valve overlap, meaning that if the valve clearances are not correctly adjusted and the valve timing is significantly off, there's a risk of the piston hitting an open valve during the engine's operation. This can result in severe engine damage. It's crucial to identify whether your motorcycle's engine is an interference or non-interference type and follow the manufacturer's recommendations for valve clearance adjustments accordingly. Adjusting the valves within the specified tolerances helps prevent the risk of valve-to-piston interference and ensures optimal engine performance and longevity. Thank you for your thoughtful questions, and I'm here to provide further clarification or assist with any additional inquiries you may have. Safe riding! I hope this gives a litter more insight Craig
@@TheRepairSpecialist That was the best answer anyone has ever given me about any topic, thank you! I will feel a lot more confident next time I adjust the valves of my motorcycle
The video is very interesting. In your experience, is it possible that all 6 rocker arms on the right cylinder bank break and not a single valve is bent? Thank you for your feedback and best regards from Austria.
Hi guys I just wanted to Introduce to you my other Channel "Kirkman's Academy" - which i'm just getting started. It's a go-to channel for simple explanations for hard to grasp subjects such as physics, maths and chemistry etc. Here is the link: www.youtube.com/@kirkmansacademy/videos . Thank you so much for looking, and if these topics interest you then I hope to see you the there. Many thanks indeed. Craig 😊👍
I cant Thank You enough for taking the time to make this video!! I can say that shamefully after roughly 5 hours of my life that I'll never get back trying to adjust the valve clearance on my 2005 Honda Recon ATV, God led me to your video!! What an ABSOLUTE answer to Prayer!! I just could not grasp the understanding of TDC on the "compression" stroke!! I was at my wits end..... I adjusted the valves I dont know how many times, but on the wrong stroke. With the help of your video, I was able to adjust the valves with NO Issues!! Thank you again SO VERY MUCH for the clear and conscise explanation, and the engine prop you used REALLY brought it home!!! Definitely downloading and bookmarking this video :) May The Lord Bless you and your family Brother 🙏
Thank you so much. Bless you to 👍👍👍
This was the most comprehensive explanation of how valve clearance works. Much appreciated the effort put in to explain for a newbie like myself. Instant subscriber
Just want to say that as your video title states- this is the only video I'll ever need to learn 4 stroke tappet clearance. 100% TRUE!!!!! After watching this video all my doubts and queries are cleared and the explaination with this model , amazing work man. Just AMAZING!!!!! I do hope you make such videos in future as well. And i request everyone to just watch this 11 min video with patience and all your queries will go away.
Thank you again for making such simple video explaination.
Wow. Thank you so much. I really appreciate your kind and very encouraging comment. Craig 👍👍👍
I am an Electrical Technologist, and this video has been very helpful in understanding engines. THANKS!
I just understood something I haven't understood for like 29 years. Awesome video
I watched it as a marine engineer cadet and helped a lot to understand the principle even tho there are some differences. Thank you!
Thank you so much 👍👍
Great job my friend. I have a 22 year old Peugeot 206 1.4i which has had a persistent misfire (P0200 and P0300) for several months (I have not driven it), I have replaced the sparks, the fuel injectors, the coil pack, the knock sensor, the camshaft sensor, done compression tests, tested the continuity and voltages across the ignition circuit, I have just replace the timing and drive belts (they were old anyway) and all that I have left is the valve clearances...I do get an occasional 'ping' during a misfire so I'm pretty confident it's the valves after watching this video....
I should add the P0200 was fixed by replacing the knock sensor...... it had cracked wide open.... was the original 2001 sensor.
What a great detailed explanation of what too loose and too tight valve gap adjustments do! I knew they needed to both be correct, but now I know why and the consequences. For your adjustment procedure, I know this was just for explanation, but you didn't mention loosening the adjustment locking screws before adjustment, tightening them after and double checking that the adjustment did not alter from tightening them enough to make a difference. Potentially, anyone who sees this for the first time could do it wrong and have an issue shortly after. You know I love your work, but I just wanted to point that out, as I'm sure others have as well. I hope you don't get bombarded too badly over it. Mine is meant as a friendly comment. Thanks for the detailed explanation, Mr. Craig. Always so informative, detailed and the arrows really help.
Thank you so much. I always appreciate your kind feedback. Craig 👍👍
Great explanation and the cut-away motor makes it so much easier for visual learners to see what's happening, when and why. Very well done.
I really appreciate your kind feedback. Craig 👍👍👍
I had a good general idea of how the valve terrain operates, but after watching your video It's clear to me. Great video and very educational. Thanks, mate.
If the exhaust is too loose it will be difficult to start, the comp release won't hold the valve open enough. The compression release is a small tab on the camshaft that holds the ex valve open just a small bit to allow easy starting, when the RPMs reach a certain speed the tab slings out of the way and allows the engine to operate normally, so if the gap is too much the tab will only take up the gap and not hold the valve open.
You are the only one I have understood now. I thank God that I managed to watch this video. I wish you all the best, God bless you.
This is a superb video. I've not seen such good - concise, yet thorough - training since I was learning to be an aircraft technician in the Royal Air Force.
Thank you very much, God bless, and let's hope the algorithm pushes this out to many more people. Chris 👍
I bookmarked this video. Emailed it to myself. Texted it to myself. Sent it to my wife's email just in case I manage to lose it.
This is gold. Thank you for this OUTSTANDING tutorial.
Mate, many thanks. Timing has always been intimidating for me. This definitely helps alleviate that fear a bit.
There aren't many folks like you mate, just aren't. This is a class A rating masterpiece. I won't say much let me enjoy your thread of videos.
Hishia, Africa - Zimbabwe.
Wow. Thank you for the awesome feedback. I really appreciate it. Craig 👍👍👍
You're the engine's boss! The best explanations ever about small engines. Greetings from Colombia.
Thank you very much! I really appreciate it. Craig 👍👍👍
This the first time I have learnt how an engine works clearly. Thanks for clearing my confusion. Explained professionally.
Thank you so much for your very kind and motivating feedback. I really appreciate it. Craig 👍👍👍
That was a very good instruction. I would like to add, because I got fooled once, that Briggs and Stratton Vanguard engines in the US call for an indicator stick, and they specify 1/4”
lower after TDC on compression as the set point. I’m not sure why, but that’s their spec.
Great tip!
I use a multimeter with a “frequency” function to set idle speed. Put an antenna on the positive input terminal, place the antenna just close enough to the spark plug wire to get a reading, not too close.
i.e: 1000 RPM= 16 2/3 RPS, or 17 hertz (rounded up). This assumes a lost spark system, whereas a distributor spark would be half that. Ok last Heloise Hint, don’t want to be a pest, but just to give back a token to repay all I have gleaned from watching your videos.
Probably the only gold star explanation of valve clearances on UA-cam. Thank you for this content, liked and subscribed👌
Thank you for kind and motivating feedback. I really appreciate it. Craig 👍👍👍
Underrated channel. Great explanation for a newie home mechanic to watch, learn, and understand! Thanks, Craig!
Awesome! Thank you! Craig
Great video Craig. I have always wondered why they went to the overhead valves. These engines having more parts seem to have more problems. I have a Techumse flat head on my 1974 Sears Rototiller and I run it every year 5 or 6 times, drain the gas from the carb, and put it away. The flat head seems like a more reliable engine. If you would, compare the flat head to your model here and note the differences between engines. Thanks
First of all, thank you for your kind feedback. I really appreciate it. And yes, you have given me a very good idea for a near future vid. I do have a flat engine somewhere in my pile of engines. I will pick out one and do a vid on the comparison, just as you said. I do have a list of a few vids to get through first but I will get round to then. Thanks again. Craig 👍👍👍
I love my flatheads, FLATHEADS FOREVER. But the OHV engine is better in practically every way possibe. Yes it sucks to admit it but it is no contest. Unfortunalty
Clearly explained, easily understood, concise & accurate. A well presented tutorial.
Thank you so much
Great video, gf was asking questions that i couldn't explain very well. Your concise and thorough video (and that cutaway engine) made everything crystal clear. Thank u kindly sir! Instant sub!
Awesome, thank you so much. Craig 👍👍👍
Probably the best ever vid on valves?
Wow. Thanks so much for that awesome comment. Craig
That was one of the best explanations I've ever heard. Brilliant. Thanks for sharing.
Wow, thanks!
What a great teacher you're sir keep it up
Best one, I shall recommend to anyone need it.
Thank you for the post.
I would give you 100%
Very well done video, now i understand how to set my lawn tractor valve clearance... Keep up the good video educational work !!!
Thank you so much for your kind feedback. I’m really pleased you can now set your value clearances. Craig
Your video is very helpful for a novice and very much appreciated.
Amazing video. So much good information. The engine cutout was extremely helpful to visualize what is going on. Bravo!
Thank you so much 👍👍👍👍👍
Great job! another great video for , all of us to view. I only wish I would have had those video's when I was 14-15 yrs & just getting into small engines, those video's & your information would have made A World of help for me. Keep them coming.
Thank you very much! I really appreciate your support. Craig 👍👍
Thanks for sharing your knowledge! Great video I’m working on a dead 4 wheeler think it jumped time so I’ve been playing with the timing and was getting tdc but wasn’t sure it was on the compression stroke now I do thank you!
This is a wonderful. So clear and concise. Very academic in presentation and explanation.
Craig another outstanding video with an excellent overview of how the internal 4 stroke engine works. Great job👍Artie
Thank you Artie. I alway appreciate your kind feedback. Craig 👍👍
Really detailed explenation... You forgot to say that there is a mark for top dead center on almost every engine...
Hi! I've been following your channel for a few years now. I do small engine repair work in Lithuania. I'm learning from my father who is an experienced repair specialist. I rely on your videos for the theoretical part of the job as many situations I encounter seem like magic if explained with no theory and only by experience and observations. I couldn't wrap my head around the saying that valves 'burn out' if the clearances are too tight. I have observed it, but couldn't figure out the cause. The same goes for the problems explained in your ignition coil videos. Thank you!
Have you got experience working on ridable mowers and their electrical components? I still struggle with troubleshooting that
Excellent. And if the valve gaps are correct and there is still poor compression it means that you have other problems, such as damage to the valves as you describe. (Hope that's not so in my case, but I guess you may have another video covering that :) )
Precisely explained.
Thank you so much! Craig 👍
By far the best explanation I have seen. Thank you very much 😊
Thank you so much for your generous words! 😄 I'm absolutely delighted to hear that you found my explanation on 4-stroke valving to be the best you've come across. Your appreciation means a lot to me, and I'm here to provide more insights and explanations whenever you need them. Keep that curiosity alive, and I'm grateful for your support! Craig
Just the right amount of information and an outstanding format for learning 👍
Thank so much. I really appreciate your kind feedback. Craig 👍👍👍
This is an amazing video. I'm very visual and learning how it all works together while trying to adjust my Ural valves is priceless. Thank you for explaining it so eloquently, easy to understand. Cheers!
You are a very good teacher.
So insightful!❤
How can you til if the valves should be offset when manual shows either or or doesn't say?
Like .004 to .008 intake & .006-.008 exhaust. Or mfg manual says .004-.006 inch on both.
But doesn't say if it should be offset for a 208cc generator.
I only hear offset the valves from the technicians by example of operation.
So offset or not?
Great cut away engine! Instead of going for top dead center, I rotate the engine until one valve is completely open (on the top of the cam lobe.) This tells me the other valve is completely closed. I adjust the closed valve, rotate until that one is completely open and adjust the other valve - which is now completely closed. This also takes the compression release mechanism out of the equation because it will not be in place with one valve completely open. I wonder if my practice is sound (it seems to be and seems to work?) So many folks do the TDC on compression thing that I wonder. Thoughts?
First of all, thank you for your kind feedback. I really appreciate it. As for the way you adjust your clearances, I also adjust the clearance this way myself. I too have never had an issue with. I find it just as accurate as the method I showed in the video. I think it’s just a case of preference really, and it seems that the more experienced mechanics among do it the way you mentioned. I think it’s also a generation thing to a degree. When I was taught how to set clearance back in the late 80’s, it seemed to be the old fashioned way of doing it. I have some old Honda engine service manuals and in them is the method you explained. I think it’s just become a little more popular in recent years to adjust them as I showed in the vid. But in my opinion your method is great 👍
You're the best teacher
Wow, thank you so much. Craig
you are a genius man i have a bike gs150 and it has 133000km on it my tapped sounds like tik tik and now i adjust tapped according to the theory you present and my bike engine is running smoothly and acceleration like boom on 2nd gear the wheely happens you are genius bro 👍👍👍👍👍👍👍👍👍👍🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹🌹
Wow/ thank you so much. I really appreciate it. Craig 👍
Brilliant video , I finally now understand how it all works, thanks for posting 😊
Thank you for such a great explanation of adjusting valves! Well done!!
Thank you so much for your crystal clear explanations, I have learned so much from your videos. Keep up the great work:)
You're very welcome! Thank you for your very kind feedback. Craig
Great video, i finally understood how it works. thanks.
Very easy to follow!! Thank you for taking the time to make this video.
Love this love to learn more about engines this was fun watching learning new thing I never knew about a car engine ❤🎉😊👍
Awesome. Thank you for watching and for your kind feedback. Craig 👍👍👍
Brilliant explanation. It cannot be made any better.
Thank you, very clearly and well explained,love it.
Thank you so much. I really appreciate it. Craig 👍👍
Great video and explanation; thank you very much. I tried to set the valves on my 250 (OHV motor) and there was no way I could loosen the valve adjusting locking nuts.. They just would not loosen... I was afraid I might strip them... The motor was on the F timing mark and both valves were closed, but even then I could not feel any "looseness" I`ve got no idea why? 😕
Great video!!! Now do I set the clearance on both valves on the compression stroke,? Thanks again!!!
Thank you so much I really appreciate it. Craig
Excellent explanation. Thank you for the content.
Thank you so much 👍👍
Hi Craig, best explanation I've seen!
Wow. Thank you so much. Craig 👍👍
This was really brilliant, excellent job!
Thank you very much! I really appreciate it. Craig 👍👍
Excellent demonstration
purfect explained and showed
Thank you so much. Craig
Thank you very much Master
Thank you so much 👍👍👍👍
Awesome video. Great job explaining valve lash!
That made my morning coffee!!!
Awesome 👍👍👍
Very thorough. Thank you!
Wow the title of this video is true thanks for making the video
Excellent explanation, very helpful. I just subscribed for more content. Thank you.
Awesome, thank you do much. I really appreciate it. Craig
Thanks for your teaching. Had no idea how it works. Question: is having the piston to its highest position is what matters to start adjustment. Correct if wrong. Again thanks and Gob Bless.
Excellent teaching!!
Thank you so much for your kind comment. I really appreciate it. Is your engine a small single cylinder like this? and could you tell me of any parts of the video that needed more clarification? I really appreciate your honest comments. Thanks again. Craig
That was an amazingly detailed video. I haven’t found it explained better anywhere else. Curious if you think that setting an intake valve .01mm over spec would cause an issue? I know some engines give a range, but my particular one on a motorcycle does not. I had it set to spec and it seems to have tightened prematurely after only 1500 miles causing performance issues. I don’t know if this is a feature of a new engine, or if I should set it slightly looser to extend the time between service. It calls for .08mm and I’m thinking of setting to .09 next time. There isn’t a lot of information about things like this. I would greatly appreciate your or anyone else’s opinion. Thanks.
Hi. First of all, thank you for your really kind and thoughtful feedback. I really appreciate it. Now to answer your question, in my opinion of course, . When it comes to valve clearances, precision is key, as even a small deviation can affect the performance of your engine. Setting your intake valve clearance at 0.01mm over the specified measurement may seem minor, but it can indeed have an impact. However, valves can tighten over time, especially in new engines as they go through a break-in period. This tightening is often due to the valve and seat wearing in and finding their fit, which can cause the clearances to reduce. If you've experienced a premature tightening after only 1500 miles, this could well be a sign of normal settling.
Setting the valve clearance to 0.09mm, a slight increase from the specified 0.08mm, could provide a buffer against this premature tightening. However, just be mindful of the potential for increased wear over time, which could lead to a larger than intended clearance if it's set looser from the start.
If you feel that you had no issues though and so are comfortable carrying on setting your valves this way then that's absolutely your choice. Every engine is unique and how it wears in can vary, I personally would just keep in mind that regular maintenance and checks are crucial for the longevity and performance of your motorcycle engine.
But anyway, thank you for sharing your experience with you motorcycle here.
Thank you
Craig
@@TheRepairSpecialist I really appreciate you taking the time to respond. I think based on your opinion I’ll chalk it up to extended break in and stick with the spec for now. The issue it was having was that after an hour or so the engine would start to hesitate, sputtering as though it was running out of fuel although it wasn’t. After checking other things I checked the valves. I don’t guess they were more than .005 tight, but it seems that it caused the issue when it got up to full temp. I wouldn’t have thought the tolerances could be so slight. Thanks again.
Muy buena esplicacion gracias Good explanation thanks
Thank you very much for your kind feedback. I really appreciate it. Craig 👍👍👍
Beautiful matey,Absolutely Terrific!,good onya cob,thank you!
Thank you kindly, I really appreciate it. Craig
Excellent video, thank you!
Fantastic explanation.
Thank you. I really appreciate it. Craig 👍
Excellent video!!
This is a great explanation.
Great information.
I'd like to see how you do valve job too.
Great suggestion!
Thank you! Great explanation indeed. One question though: is my understanding correct that during a one full cycle the magnet on the flywheel passes by ignition coil twice? If so it appears to me that we get on spark at the end of compression and one more on exhaust? I'm not very sure how that works and everybody seems to say there is just one spark, and that is reasonably.
Thank you for kind comment. I really appreciate it. Secondly, you are absolutely correct about the spark firing twice for a full revolution of all four of the engines strokes on these small single cylinder Engines. Other people who have told you they do not fire on the exhaust stroke are confusing themselves with larger engine that use a battery to charge the sparking system to generate the spark. These systems have more advanced spark timing. These small lawnmower engines, however, are not that advanced.
They do not use a batter to charge the sparking system. Instead they use the magnet on the flywheel and the ignition coil pack. Every time the magnet passes the coil pack it will generate a spark, as you correctly said. This means that after the magnet has passed on the compression/power stroke, it's one full turn from this will indeed be the exhaust stroke, which is where the spark plug fires again.
Why does it do this? Well simply because of the design of the magnets positioning on the flywheel making for a simple and easy functioning sparking system function. Of course, the side effect of this system when it was developed was that the spark plug would fire on the exhaust stroke as well, but this was to NO detriment to the engines function what so ever.
On other larger engine types where the spark plug fires on the exhaust stroke, it is known a wasted spark system. Take a google search and search for this: Wasted Spark System.
I hope this helps
Craig
Wow this is a fantastic video... So much information.. ta mate
Thanks mate. I always appreciate your kind feedback. 👍👍
thank u sir was waiting for this ,you made it so easy to learn
Wow thank you so much very interesting and educational 👍
You are very welcome Thank you
Great tuition Video, Keep up the good work
Well explained 👍👍👍👍
Thank you 😃
Very well illustrated, ❤❤❤😊
Excellent video. I wonder if it is safe to use a rope to lock flywheel of lawn mower so that I can remove nut? I saw in one video guy said it is not safe to use piston stop tool on large engines like lawn mowers. Some guys using rope, but some saying could be issues with valves. I have a feeling it should be safe to put a rope in the middle of compression cycle as the both valves will be closed. Am I right?
Hi. In my opinion, using a rope to lock the flywheel of a lawnmower can be a useful method for preventing the engine from rotating while you work on it. However, it's important to use this method correctly to ensure safety and prevent any damage to the engine.
Your understanding is correct: When you insert a rope into the spark plug hole and position the piston in the middle of the compression stroke, both valves should be closed. This is a safe position to lock the engine because it prevents any potential interference between the valves and the piston. It's a common practice among mechanics and DIYers for performing maintenance tasks like removing the blade or working on the crankshaft nut.
The key is to ensure that the rope is inserted far enough into the cylinder to provide adequate resistance when you turn the crankshaft nut. This resistance effectively "locks" the engine, preventing it from turning while you apply force to loosen or tighten the nut.
Using a piston stop tool is another method, but as you mentioned, it may not be suitable for larger engines like lawnmowers. Using a rope is a practical alternative, and as long as you follow the correct procedures and ensure that the rope is properly inserted to stop the piston, it can be a safe and effective way to work on your lawnmower engine.
Always exercise caution and follow safety guidelines when working on any machinery, and consult your lawnmower's manual for specific recommendations related to maintenance and repair procedures.
Thanks
Craig
Excellent teaching moment. :)
Thank you 👍👍👍
Mr good simple description
Great illustration👍
Great video. Thanks!
Excellent video
Thank you very much!
Top video mate 👍
Great video.. thanks
You're welcome! Thank you 👍👍👍
Just the video I wanted to see
Great video love learn alot
I always adjusted the valves of my motorcycle myself, but only because it is part of the normal maintenance checks, and never really understanding the underlying reasons. Now I finally have a much better picture of why we sould keep good track of it.
However, I wonder why we have to do the adjustment at exactly top dead center, since both valves are completely closed during the whole compression stage. Couldn't we do it at just any point of the compression?
Also, I often hear that if the valves are not correctly adjusted, there is a risk of one of them falling inside the cilynder, causing the complete destruction of the engine. How would this happen?
I'm delighted to hear that you found the video on adjusting 4-stroke valve clearances informative and that it provided you with a better understanding of this crucial aspect of motorcycle maintenance.
Regarding your questions, let me clarify:
Adjusting Valves at Top Dead Center (TDC): Adjusting the valves at top dead center is a common practice because it provides a known reference point where both valves are fully closed during the compression stroke. This makes it easier to set the valve clearances accurately. Working at TDC ensures that you're adjusting the valves when they are in the correct position relative to the camshaft lobes and lifters/tappets. While it might be possible to adjust the valves at other points in the compression stroke, doing so at TDC simplifies the process and minimizes the risk of errors.
Risk of Valves Falling into the Cylinder: The concern about valves falling into the cylinder if not correctly adjusted typically applies to older engines with certain design characteristics, such as non-interference and interference engines.
Non-interference engines: In these engines, the piston and valves have no overlap, meaning they cannot physically collide even if the valve clearances are significantly off. Adjusting the valves in such engines might not result in catastrophic engine damage, but it can lead to poor performance.
Interference engines: In contrast, interference engines have piston and valve overlap, meaning that if the valve clearances are not correctly adjusted and the valve timing is significantly off, there's a risk of the piston hitting an open valve during the engine's operation. This can result in severe engine damage.
It's crucial to identify whether your motorcycle's engine is an interference or non-interference type and follow the manufacturer's recommendations for valve clearance adjustments accordingly. Adjusting the valves within the specified tolerances helps prevent the risk of valve-to-piston interference and ensures optimal engine performance and longevity.
Thank you for your thoughtful questions, and I'm here to provide further clarification or assist with any additional inquiries you may have. Safe riding!
I hope this gives a litter more insight
Craig
@@TheRepairSpecialist That was the best answer anyone has ever given me about any topic, thank you! I will feel a lot more confident next time I adjust the valves of my motorcycle
Good lesson, but I wonder how to find the TDC in a multicylinder diesel engine fitted with prechambers and not externally marked with some indication.
The video is very interesting. In your experience, is it possible that all 6 rocker arms on the right cylinder bank break and not a single valve is bent? Thank you for your feedback and best regards from Austria.
Very very thanks... Sir
Thank you 👍👍