I spent 17 years in the industry building two-stroke expansion Chambers and loved every minute of it.

When I was a teen I used the spare time teens have wisely. I used to buy crate bikes that nobody knew about or had long forgotten. Jawa, CZ, Penton, Bultaco, Montesa, Ossa - and make them absolute museum pieces. New or better than new. Then make a fitted cover and my mom would embroider the logo and sew, my dad would waterproof them. Buyers came from far away and NEVER haggled on price. These machines are works of art and should be treated like precious treasures and rode into the ground like ya stole it. When you ride one and it gets the wind in your face and you and the bike become one and you find your pace, that happy place where the two of you just tick: replace THAT! When you look deep into it's paint work so rich and deep and flawless...see the sun blinding you off the chrome...You jump back on it to ride it LOTS more! It's a love affair, man. I could NEVER be happy with factory new being "good enough".

Я просто в шоке! Сколько проделано работы😐 Титановый труд. Я ремонтирую явы, посмотрев это видео, я понял что я не ремонтирую явы, я их протираю от масла! Автор просто проделал очень серьезный путь👏 Красава

Dear Mr von Stern. Thanks for sharing another extreme masterpiece of skill & mechanical beauty. There won‘t be many people on the planet who invest such a level of endurance and passion for their vintage bike. Keep up your wonderful work.

Nur wirkliche Liebhaber beherrschen einen solch perfekten Job...sehr gut👍

Просто великолепная работа👍 Парень, ты просто гениальный мастер, прими искренние слова с уважением

As a fabricator and welder of 30+ years I can truly appreciate the skill and craftsmanship in making these. Excellent job, I bow down to you. Beautiful pipes. In a future project I suggest tack welding your entire pipe together then filling it with a constantly replenished supply of argon (back flushing). It will give a cleaner weld on the inside and a stronger weld for resistance to metal fatigue.

Уважаемый мастер, похоже Вы до 100 лет будете увлечённым своей страстью к качеству исполнения и к полёту мысли!🎉❤😊😊😊

I've watched every video of your jawa tuning, this work is absolutely brilliant and well done , in each detail. I'm a two stroke lover since childhood and i completely agree with what you have done. Decreasing crank weight, converting the piston port to reed valve... everything made respecting the original look of the Jawa. Very pleasant to watch till the end, i hope you make more videos for a good listening to this singer! It runs like later ari-cooled cross with many rpm and a lot of torque at low. As i expected you had issues with gearbox and clutch system, but you solved brilliantly. I've recently got a spare cylinder for my californian 250 and i was thinking to work on the cylinder, not something so radical but definetly they have good potential. Still thank you for sharing these brilliant work, have a nice road :)

Siegfried, You have amazing talent and patience for that matter. Great to see tuning work on a Jawa for a change.

beautiful work as always ...looks stunning

Ein Meisterwerk der Handwerkskunst👌

For man, who was born in the same country, where this bike was produced, is this project something special... Amazing work 👋👋 Always great to watch your videos

Erstaunliche, super professionale Arbeit. Noch dazu in einem sehr sympthischen Video verpackt - dankeschön!

Evil sound! Perfect job! My first bike was the Jawa and now I'm thinking about it again, thanks a lot for the video!

Your level of craftsmanship is unreal , great job 👍

Diese ganze Arbeit,der Wahnsinn absolut 👌

About 12 years ago, I designed & built the entire exhaust system for my 1988 Jawa 500-826 500R Mk.II. I ran the numbers and deliberately made one of the headers 8cm. longer than the other, which causes the Rotax 504 engine to ease into "coming on the cam" at 6,000 RPM, fully light up between 7,000 to 9,000 RPM and rev out at 10,000 RPM. The silencer is a cut shorter 638 silencer (for the megaphone effect) with the innards of a Micron race can with added adjustable backpressure tubes (because 4 stroke singles hate straight through pipes / need backpressure). Top speed was up from the strangled stock 95 MPH to just over an indicated 115 MPH.

Sehr geile Arbeit Siegfried, viel Liebe zum Detail und am Ende ein perfektes Ergebnis! Habe dich heute erst entdeckt weil ich krank im Bett liege aber davon möchte ich gerne mehr sehen, mach weiter so. 👍

schöner Sound und super gute Arbeit!

Оно этого стоит Грамотно и красиво получилось 👍👍👍👍👍

Ale masz fajny przyrząd na prasę do małych stozkow 😀 piękna robota.

Excellent work done.State of the art!

Damn, I am envious of all the skill, money, time and equipment you have.

Freaking cool work, well done 👏

fantastic- waiting for a video on speed checks with this setup !

Absolutely amazing job 👍

Beautiful work bro those are some amazing looking and sounding pipes 👌😎

Enjoy watching your work ♥️

Absolutely superb, many thanks

Excelent tunning jawa...great work and badass sound 😎

Εξαιρετική δουλειά, φρεντ!! Μα άξιζε τον κόπο, το μηχανάκι αυτό ειν αργοστροφο, κ λίγη δύναμη να πάρει ακόμη δεν θα του φτάνουν φρένα, αναρτήσεις, λάστιχα μετά... Μπράβο, πάντως!! ❤️

The out come is beautiful

Great video love the sound of it

pěkná práce, motor jde krásně do otáček

Sound Amazing ! Again,again...

Unbelievably good !!! UNBELIEVABLY GOOD. AMAZING AMAZING LOVELY WORK, MAN !!!

Beautiful!!!

Sounds nice, a lot of work for something that might work or might not. there is so many variables in to making a 2-stroke exhaust pipe that its almost always hit or miss :D

Cool great done

very good work - perfekt sound!!

Sounds lovely...

Beautiful Sound ♥️♥️♥️💨

nice job, compliments👍

looks Realy NICE

Wow, great work 🔥

Delightful.

Well that's a beast right there😏

It is brutal 😮

Просто шедеврально!!!!!!)

Very cool

Sehr schöne Arbeit 👍

Respekt! Du hast was drauf!

looks very professional to me. great welder

min 4:56 ingenius tool, Good job!

Absolute Meisterarbeit!

tolle arbeit mein freund... respekt

Instant subscription. Amazing work

Прекрасна робота .

Super video

Mega Handwerk so was habe ich noch nicht gesehen ich bin schon 63 Jahre top genial

Perfect work.. 👌👌👌👌👌

Optisch eine Wucht. Prima!

If it’s faster- then it’s better! Great 👍 work

Hut ab! Richtig schön gemacht, genau so muss das aussehen . Ist schon sehr lange ein Traum von mir einen Resoauspuff wie deinen, komplett selbst zu berechnen und zu fertigen. Hab für meine Ktm comet einen Leovince ZX Resonanzkörper mit dem Endschalldämpfer einer Zigarre verschweißt. Sieht deinem Schmuckstück ziemlich ähnlich. Respekt und Anerkennung aus Wien 😉

nice job 😍

Building my rezonator on my 60/4 S51 (with a 21mm Dellorto carb and factory 4 speed gearbox) was the single most huge powerup step of all the things I did to it (to reach a stable max speed of 100kmh)

Дуже гарно все зроблено) мотор працює неймовірно добре...

Саунд божественный!

Sehr schöne und präzise Arbeit. So einen Auspuff könnte ich auch gut für meinen Berlin Roller gebrauchen 😁

That's good!!!

great!

Мне одному не звучит? Руки золотые,моё почтение.

Легенда просто!

My first bike in 1975 man was it fast 😮

Those pipes would look awesome with fins!

Hammer Arbeit 👍 Wobei eine RAW Optik mit den Schweißnähten auch ganz witzig gewesen wäre. 🤣 Natürlich nur Spaß. Sehr schön!!

I'm curious about power gain..is it gave you the expected performance? More top end power or bottom to mid?

Waooo!! I need this

Highly appreciated work. 👌👌👌👌👌👏👏👏👏👏👏. Happy to see this video. Please let me know if there any possibility to buy this kind of similar calculated expansion pipes of same quality.

Bravo👏👏👏👏👏👍

👍👍👍

С ума сойти Вы кто? Уважение зашкаливает

Amazing work and awesome welding! Can I ask what settings you were using on your welder to prevent burning through such thin metal?

Hi, Mister Sieg. :) i'm just wondering do you have any plan's for tho exaust's? or even better question... would that exaust wor ok. on Jawa 350 TS 2 cyl.? I would like to make some better exaust for mine... so I would be happy if you would help me... thank you very much in front...

Sensacional 👏👏👏👏👏🇧🇷🇧🇷🇧🇷

Geile Scheiße, eine feine Anlage! Und auch ein schönes Video!

👏👏👏👏👏👏

👍

wow😎

Great build, top. Any more news on the project?

great skills and sound ! congrats! how does the TÜV guy react?

Impressively colossal amount of work. I made many pipes without having to consider smoothing and chrome plating so your job is way harder. I am curious how you generated your flat patterns for the sections?

Beautiful job!! I am going to build exhaust for my Jawa 50, but i have a question. What material were you using? What steel grade should i look for?

Oh my fu*king gosh! That is beatiful work. Are you from Germany? Lets arrange some small trip in the spring! :)) I have to see it with my own eyes.

I came across your video series on my fathers' phone. On his last days he was watching these video's. Begging for time to begin tuning his personal CZ250 Sport. Now that'll be up to me. However, no parts are available, only to be crafted. So that'll be a long journey. However, I also was thinking to transform it into electric powerhouse, which is more my thing and is readily available. But... Two strokes man... The memories are amazing. Racing together with my father, so that'll be first choice. You know any place where I can get old spare engines or parts for some more power?

It looks amazing, how much s Would a full engine and setup cost?

Do you grind the inside surface? Do the welds negatively affect the flow and turbulence inside the exhaust?

You're well on the way to joining the very small exclusive club of Jawa CZ riders that have managed to do the "Ton" (100 MPH / 159 KPH) on a modified 2 stroke production Jawa CZ motorcycle.

Hey there,nice work man I love it, ❤❤ I need to contact you man, cause I want to build a pipe but I don't have the book ,is there any chance I can get a pdf file?