"First, I love you" You don't even know how much a lot of us needed that...

Compression issues? Maybe it's finally time to buy that WinRAR license...

0:05 As a wise man from the north once said “Tappy Tap Tap...”

Just chuck the cylinder head in the freezer for a bit and that bore measurement will be proper good :)

Apparently regular maintenance on a trials bike is every 25 miles.

“Just to be sure, I changed both brake rotors.” Classic!

Watching this totally qualifies me to fix someone else's bike now.

For future endeavours Tony, A leak down test is arguably more important than a compression test with two stroke engines. Basically you plug the intake on the carb, and the exhaust on the head, and pump it up through the spark plug hole to around 7 psi or so. It should hold for a few minutes. If pressure drops some over a few minutes, or bleeds off entirely, you can use soapy water to find the leak. This checks for seals on the crank, reeds hanging open, case damage, reed block gaskets etc. I havent seen the reveal yet so i dont know if you were right or not, but its a good test to keep in mind. Especially if you find its running lean and cant fifure out why. Also, as im sure you know, every bike has a service life for the top end, X amount of hours.

“...kick this thing like it owes me money...”’ I always suspected ToT was a loan shark for the mob.

For the curious: the reverse audio part was, "The only thing I'm changing are the piston and the rings."

After watching my European heroes contest an Inter-Am motocross meet, I went out and bought a 1970 CZ 250 MX. I had never ridden a dirt bike but assumed I would be an instant Joel Robert on such a mount. The owner's manual did not expand on the terms of the factory warranty (Both Halves Are Yours), but rather gave instruction on how to win races. Before each contest, it suggested, I should fit a new piston and ride the bike hard to see if it seized, repeating the process until satisfied that the piston would last the race. It also recommended a new chain for each race. CZ chains had individual bronze sleeves between each roller and pin, and were priced accordingly. Being used to torquey street bikes, I stalled the CZ several times before getting it moving for my first ride. Broke my collarbone twice the first year I had it, and never had so much fun in my life. Every once in a while I watch a VHS copy of On Any Sunday to relive the thrills.

I wasn't believing my compression tester one day, it was saying my perfectly running car had 0 psi of compression. Turns out the adapter side had a wasp nest in it and the schrader valve on the other side was rusted. Cleaned those out and it worked perfectly. Even with little use, just checking and spraying with WD40 every so often works wonders.

So, just to mess with you Tony. Pistons are not machined perfectly round when cold. They are machined to grow to circular when at operating temperature. Even el cheapo pistons. Forged race pistons have full 3d machining for growth at temp. The piston bore is also not checked or bored just sitting free air. It should be torqued down with torque plates to simulate the stresses of the head and block in place, which changes the bore shape due to the elastic deformation of the clamping loads. On your trials bike, you found it's a thousandth or less. Hard core race engines are bored at operating temp with torque plates installed to simulate the head, accessory, trans and block deformation and are effectively seized when not clamped together to create the clearances.

3:35 “and the kill switch is on” don’t forget that, don’t want it starting with that compression tester in the spark plug hole

Excuse me TOT, there are at least 3 of us who wanted to see the inside of that cylinder bore.....thanks for sharing.

I'm starting to get that twitch that I get when I'm coming down off of TOT, pretty soon I'll be breaking into my grandmother's house, rifling through her VCR collection to see if there's any TOT on there, hanging out on street corners, offering favors for just a little fresh TOT. I get chills every time I walk past my local machine shop, they won't let me in anymore... I got so excited yesterday when a guy sold me a USB stick for $20, he told me there was some fresh TOT on there, but it was just some Abom79. But in all seriousness, I hope you and your family are safe and well and I hope you're back with a video soon.

This Old Tony existentially essential in these here difficult times.

809k subscribers 15 years from now: "There's no way I'm paying someone else to do what I'm fully qualified to do myself since I watched that video fifteen years ago."

I've heard that if you use a green marker instead of blue, and go arround the edge of the piston, you get better sound.

What's a magazine article?

Nothing's out of spec here, you just happen to have a B cylinder now.

I feel like the old this old Tony was hardcore enough to have made that piston.

If ToT is an amateur, I’d be terrified to know him in his professional capacity. 😍

Tony, I’m baked and this feels like high school shop class. That was 25yrs ago, lol. Thanks so much for the memories. Keep it up.

4:16 AM wife sleeping Me: watching This Old Tony Life is good. For now!

Tony says "hone the bore" I heard the h and b get swapped, but then again, I've been in lockdown for too long.

If ToT can feel ridges is the piston with his finger nails, that scoring must be deep. Just kidding TotT :)

Tony, do you ever think, "A quarter of a million people watched this in a day?" You deserve it and more. Baby, you're gorgeous!

When the "Emergency Alert" went off, my cat, who was sleeping next me. Woke up freaking out, looking all around. Was pretty funny. Thanks for reading!!!

AWWWW This Old Tony, I love you too 🥰

I’ve been waiting for a decent LONG upload for so long now. Aghh , nothing on Netflix compares to your educational antics 🤣

20:28 dying looking at that B on the piston head

This is a truly memorable moment, I don't think you've ever told us you love us before 👊

9:18 As you can see, the piston is pregnant and wearing a tank top.

This Old Tony, it's always worth watching to the end. As always, great content! I'm a land surveyor & woodworker and just from watching your videos, i now know i need to stick to those things. HA. Kidding! Thanks for the awesome videos, I always get excited when i see the new ones pop up in me feed...I don't use the bell icon, i like to be... Thanks for reading.

This was just a random KZfaq recommendation but i have never been so entertained by a KZfaq mechanic lol amazing content

*shows the old ring gap Me: DEAR GOD

Quite enjoy your mechanic videos! On a sidenote: pistons and cylinders aren't necessarily meant to be cylindrical when they're cold, they're often manufactured to account for different heat expansion due to their geometry, so a measurement of roundness might not always be super meaningful.

Thoroughly enjoyed that, like the humour and the technical content. Amazing how watching someone else work can create so many experts!

Well it is a dirt bike, it’s supposed to run on dirt, right?

AvE Aaaand This old tony on the same day. What a treat!

You can make anything look or seem interesting, ty for the content

this is the struggle of building engines at home. You make it seem hilarious and fun. I miss the honing machine I used to run along with all the other machine tools that made it look easy. Good job!

I've rebuilt many 2-smoke bikes in my time and you did everything right. You are exactly on the money with the Nikisil coating, the only thing I ever do is light clean it with a Scotch-Brite pad. The new rings will take time to bed in. I first rebuilt a 1977 Honda MR175 Elsinore 2-smoke, I borrowed a book on rebuilding 2-smokes from the library and did it in my dad's garage. Great video!

HE SAID HE LOVES US!!! Ughm, i mean... we love you aswell, Mr Tony

Well, atleast 30 minutes of my day was enjoyable. Thanks Tony.

Those markings you made on the piston, pure art baby!

Man, Tony, I knew nothing about combustion motors but I do now (and I am just half way in your vid!) You are explaining things like every teacher and howto-vid should. Love your vids, keep it up, keep the fun it makes your videos worth to watch. Even if the thematic isnt even close to interest. I learned so much about stuff I never had interest in. You rock!

0:50 thank you for also displaying the cup size for the imperial folks.

TOT: "for the two curious people out there..." Me: "I'm A Wild PIiiig!"

Another great video. (As always!) 🤙 As a lifetime dirtbike rider/racer and a hobby machinist, I really enjoy when you bring the two subjects together. Ps. To really get the most performance increase out of doing a top end you might want to throw in new clutch plates and clutch springs (or in a pinch stack an extra washer on the clutch springs) to ensure that the horse power increase is making it all the way to the ground. You’d be surprised how a slightly worn clutch can keep you from feeling the full performance increase.

Awesome as always Tony! brought back memories of machining window ports in Hodaka pistons for reed valve setups. ATB, Robin

(3:35) - "Now I'm gonna kick this thing like it owes me money..." I had to crawl back up off the floor to just type that. >

Dyslexia got the better of me with "hone the bore" read backwards.

dude i love your videos, your humor is too good. keep making these, love them so much.

I want to say thank you. Your channel is great, The special effects and the humor are the best!

"Great, now I've got the hiccups". That line caused me to spit beer out my nose. Thank you so much for another wicked smart and funny video.

Always my favorite KZfaq channel TOT. Haven’t seen a TOT video that hasn’t put a smile on my face or a laugh yet. TOT for president 2020. GW

This channel is just ridiculously good. The quality of production and information do not deserve to be free. Much appreciated Mr. Tony.

Love your vids! Been binge watching. You’re like Ave but your jokes and humor are actually funny!

As I logged on to KZfaq I thought to myself “ I could really do with a ToT video now” - and would you guess what...an half hour video. I love this channel 😫

Your wit is indubitably the best on KZfaq that I've found so far.

Learning lots and having fun. I really love your channel, Tony. Cheers.

Thank you for making it! Although I do only basic maintenance on my bikes and would never attempt such a repair, it was an entertaining video. Thanks!

I'm not an engineer, and In know little of engines. So i can definitely tell you that an engine like that does indeed require PSI to start. Good luck!

"That was long" -- please more ~30min videos, i enjoy them

I really like your videos Tony. They are funny, good looking and i every time even learn something :D

Hey, man. JUST discovered your impressive collection of work. You are providing such a fun service here for guys like us. Used to think I was "handy", but after viewing many of your collection, I stand corrected. Would enjoy having you as a neighbor! I mean, really, what can't you figure/fix/improve? Impressive work, sir. Keep it up!

1:07 Haha hiding going the wrong way by changing the battery :D Good one!

You can make your video's an hour long if you want. Always enjoy them so much!

man, ToT, you never miss a beat. All them jokes are superb. Don't mind waiting months for your videos. Even years, you'd just a finer aged wine!

I stuck around. Your welcome bro. I get entranced watching your teaching tutorials bud. Keep em comin

I honestly didn't notice that it was a "long" video.

The easiest way to fix the problems with your bike is to buy a new house that comes with a new bike in the garage.

Fantastic video TOT - as always, I learnt something, and it was entertaining & fascinating! I was suspecting / hoping you were going to machine your own new piston matching the bore precisely, with tight tolerance on all gaps, multiple measurements at different temps to bring it from slightly oval to perfectly round, or to perfectly oval matching your bore . . . but what I saw was good enough! Please get yourself a high quality compression measuring tool, you know you want one, we need you to have one, and calibrate your air compressor and tools etc. I'll buy a shirt to support these purchases . . . thanks for everything & stay safe!

I’ve rebuilt hundreds of two strokes over the years, you didn’t make a single mistake I wouldn’t have. Great work.

Mr T, 90 is a bit low for a 150psi cylinder - with new rings. I normally see closer to 135psi on a new rebuild of that size, and it'll quickly tighten up and make its way to 150psi over a little bit of running time. Also, check out a leak down tester for the cylinder vs a standard compression tester. You to put the piston at TDC (or crank in the case of a 1cyl), and put compressed air into the cylinder to your desired pressure. You then wait. The leak down tester has a gauge on it, and you watch it with exuberant anticipation... and it slowly leaks down, crushing your soul, or not. Anyway, they're great for getting a better idea of cylinder and ring wear on a 2 stroke. The leak down will show wear that a compression test will not.

Tony: Pistons, the tarot cards of the engine world Mazda doritos: 🙄

actually those tips you pointed out @9:12 was very important. its details like that(+ snarky sarcasm comedy) that keep me coming back and watching(re-watching) your videos.

Doing the exact same thing with my bike except it is a 4 stroke 250cc inline 4. Learning a lot of lessons (the hard way) and this video taught me even more.

7:28 Confirmed. This Old Tony and ProjectFarm are neighbours.

"All over my bullets and everything!" Hahahahahaha!!!! I think I need some tacos now.

I enjoy your sense of humor. I look forward to it in every video.

Thank you! Yes! I stuck around till the end, and I thought it was most definately worth it! Yes, ofcourse I would have liked to see you hone (also own?) it! But, I stand by your decision, and I would have done the same. Again, you are truly a fountain of wisdom and good humor. Thank you so much. Alicia from Sweden.

When you pulled out the second piston I was waiting for the “I hope you can hear what I’m seeing”. Love you too Tony. I hope that intro wasn’t a jab at blondihacks... still waiting on the video of you straightening out her parts...

I did not just "stick around". I thoroughly enjoyed every joke and reference. Especially the tootsie roll one!

Just an aside, thank you for properly calling this an ENGINE!!! The entire world can't seem to get this right (motor),,, I've been screaming (it's not a motor) about forever and here you go out of the gate and call an apple and Engine! Seriously, I couldn't be more proud of humanity then I am of you right now!!!

Really enjoy these longer vids. I learned a lot from that, thank you.

Was kinda shell shocked, after an unfamiliar sentence, so I had to rewind a few times. What's next? A hug?

Speaking as a mechanic I was taught and have found that most engines won't run under 100 psi (at least not well) and wont run great under 120 psi. That is kinda a good reference to go with I have found

As always, most entertaining, & informative. A nice digression.

I had a side-gig in a motor shop for a Motocross race team for a little under a decade. I'm not going to go into any "advice" as well, as you said a dozen mechanics, a dozen answers. To answer your question on compression to draw fuel. We found that smaller motors usually around 80 on the gauge and it was only starting when hooked to a tow vehicle. Considering you went to spec on everything, your compression is more than adequate. The only other thing to say is when you checked the piston crown height at the top of the bore, you can get different thickness of base gasket to adjust your "squish" to make the most of the explosive forces in the cylinder. "Squish" is exactly as it sounds. Take a couple of pieces of the softest solder available, put it in through the spark plug hole and allow TDC to squish it flat. do both intake and exhaust side. measure the squished solder and boom bobs yer... [jump cut]

I'm a 39 year old man, and I have to admit, when I saw this is said "a new TOT, and it's 28 minutes! Sqweeee!!!!"

Still waiting on that surface gauge build ;) Love your videos Tony. Easily my favorite channel on youtube.

Not gonna lie, when I see a new video from TOT in my notifications, I legit feel giddy. Like I get to open a present. Thanks, This Old Tony. You truly are essential.

I love you too, Tony! I'm planning to get a 125cc trials bike and learn some engine maintenance on it, so a video like this is basically invaluable. As well as very entertaining :D

20:39 Thanks Tony, I really needed that 😢

Sounds like you need to compression test the compression tester.

I have watched several of your videos and determined that if you are not an instructor you have missed your calling. Great videos .

Oooops , gearbox oil, that'd be a four stroke engine chap, great channel, great humour! Love it! 🇬🇧