Kawasaki Estrella エストレヤ RSx360 (1996) Cafe Racer vs. home made engine parts

In 2015 I had chosen to make the Kawasaki Estrella - also known as BJ250, or little W650 - a bit faster and slightly more sporty. A little bit of wind from the front and it would hardly reach 100 kmph in original condition. What a pitty for bike I really like for its beautifully clean engine an its overall simplicity. But when I started the project quite quickly I had to realise that there are hardly any custom parts on the market and basically nothing for a „hotter“ engine.
In the end it took a couple of hundred hours to fit the engine with a home-made titanium con-rod (small end Pin 18 instead of 16 mm), a customised piston and cam shafts which went through many hands to get developed. Bore is 79.2 mm now which results in 360 cc given the stock stroke of 73 mm. The power output of the bike has almost doubled relative to stock which is why secondary transmission is now 18/35 instead of 15/38.
After all, it makes a lot of fun to ride this little 135 kg / 35 HP fun bike. And I think it looks quite good considerring that only smaller modifications were made to the base of it.
Thanks for your positive comments.

[@1978JonBullock]

A true labour of love. Outstanding engineering and design, she really is a true one of a kind.

[@Q.L.Engineering]

Thank you, Sir.

[@hanksplanksproductions6454]

Fantastic work Seigfried , I've been looking for some tuning ideas a 250TR engine and couldn't find any at all apart from noisy mufflers . You've certainly pushed it to the limit with superb ingenuity. Great job 👏

[@Q.L.Engineering]

Thanks. In case you are interested in a plug & play 300 cc kit: [e-mail]

[@mrmoto2715]

Die Estrella meiner Träume... Danke für das Video!

[@Q.L.Engineering]

Danke für das Feedback!

[@brandonevans9252]

I have an Estrella. I live in Vietnam. They're very good looking bikes!

[@Q.L.Engineering]

Indeed Mate. All the best!

[@mattiasgruebe1112]

Wahnsinn! Präzision in Perfektion und schön noch obendrein!!!

[@Q.L.Engineering]

💪🏼💪🏼💪🏼👊🏼👊🏼👊🏼

[@АлександрНовоселов-ж3т]

Проделана коллосальная работа,нигде подобное не видел,если ещё что то снимешь буду ждать, твои видео вдохновляют....

[@Q.L.Engineering]

Привет, Александр, большое спасибо за поддержку!

[@Tiff-Toff]

Junge du bist einfach nur krank und das meine ich aus vollstem Respekt! Absolute Spitzenarbeit und eine hinreißende Beau die du da gebaut hast!

[@Q.L.Engineering]

Danke Kamerad. Ich werd’s meiner Frau weitersagen 😅

[@s.a.f.r.a6403]

fantastic workmanship

[@Q.L.Engineering]

Thank you, Sir.

[@kuikukui5077]

Brother, make full video blog about customizing. Slideshow is not enough. Great job although !

[@Q.L.Engineering]

Sorry Brother. At the time of making this bike I never though to bring it to KZbin one day. Hence not enough video material captured. Anyways, I’m far from being a professional and that’s not a problem for me. And the slideshow still is some fun for the one or the other. 🤞🏻🤟🏼👍🏼👌🏻

[@doctordapp]

What a fantastic finished project, good job!

[@Q.L.Engineering]

Thank you, Dr. Dapp.

[@ИгорьЮрьевич-м4д]

Спасибо, очень интересно, живу в Сибири имею Kawasaki 250TR,для нашего региона это очень редкий мотоцикл и я им доволен,но Ваш проект просто потрясающий, браво!!!

[@mathiaskling6154]

I think most people (me included) follow you mostly for the 2 stroke Jawa, and don't care about the 4 strokes. But that's too bad, because this really shows off your amazing still as an engineer. Especially when you made that custom conrod i was absolutely amazed!

[@Q.L.Engineering]

Thanks for the compliments, Mathias.

[@immedal8618]

Menuda sobrada de trabajo.. Alucinante!! Espero que sigas subiendo más videos!

[@Q.L.Engineering]

Thanks. Yes, there will be a few more. Mainly about vintage 2-stroke bike modifications.

[@grando75713]

I watched a Estrella improvement video. Meanwhile, my Estrella is sitting in a parking slot and can't even start. Good job to you and i have to so much to learn from you.

[@Q.L.Engineering]

Welcome, Sir.

[@mebeasensei]

I have a w650 i have messed with majorly, and a beautiful little Estrella solo seat style with fron t and rear disks ('95ish?) model. I have to sell one and restore and beautify the other. Having a hard time deciding which one

[@Q.L.Engineering]

Difficult. The W is the faster, professional but much heavier bike. The Estrella almost as easy to ride as a bicycle (with engine).

[@mebeasensei]

@@Q.L.Engineering Yeah, and i live in Japan. The Estrella being a 250cc bike doesn't need to pass a two-yearly inspection. The W does, and each time it costs 80,000 yen (Works out as being about 3000 yen (about 30 US dollars a month) a month just to keeo it registered. My W is also a bit of a mess, having chopped and changed a lot of parts. Nevertheless! It is a glorious W.And being a 650 has a kick-start! Which the Estrella doesn't. The W is way more powerful and feels like a Concorde compared to the Esty which is a Dc3. But the Esty is gorgeous as is, and being largely untouched, would come up like a gem. Also, touring over here is either boring freeway or low speed back roads. So 40-60kmh is a common speed.

[@Q.L.Engineering]

That‘s expensive! Unbelievable costly. We have such a check for every motor vehicle on the road here every 24 month, but is way cheaper still. I love the Estrella with 30+ HP. It‘s the ideal bike for me.

[@alexbut9487]

Очень красивая пушка!!!! Объём работ колоссальный, в итоге- Зверь красивый 👍👏😊

[@Q.L.Engineering]

Thanks Mate.

[@cornuclaude1646]

waouh, superbe travail magnifique .

[@Q.L.Engineering]

Thanks for the positiv feedback!

[@philsmith1087]

Fantastic project, love it. The music made my head hurt!

[@Q.L.Engineering]

Thanks for the comment. Many people like the sound. Different taste, different preferences…

[@lazyloyz3380]

Just speechless. GREAT!!!

[@Q.L.Engineering]

Thanks for the friendly feedback!

[@svenwalleck5566]

Was für eine Fantastische Arbeit. Ich bin sprachlos. Könnte meiner W beinahe Untreue werden..😉 Wenn Präzision und Herz zusammen kommen, kann nur gutes daraus werden! 💓👍👍

[@Q.L.Engineering]

Danke Sven. Sehr freundlich. Die W bietet im Grunde sogar noch mehr Potential in vielerlei Hinsicht. Mir ist sie aber schon wieder zu „groß“ und schwer…

[@svenwalleck5566]

@@Q.L.Engineering An dem Gewicht habe ich schon gearbeitet( Original Gewicht hat Sie nicht mehr ) Nächste Stufe : 855 ccm Kit. Schöne Feiertage!

[@2000NRJ]

Hey, Can you please let me know if you have the wiring diagram of this bike? Thank you

[@Q.L.Engineering]

Please check German web page: Estrella-forum.de. You need to issue a personal post. They may be able to help by means of a scan of it…

[@2000NRJ]

@@Q.L.Engineering Thank you. Appreciate it.

[@aroundus7408]

Cool, love your job. I wish can make it like you.

[@Q.L.Engineering]

Thanks Mate.

[@francismbaabu1959]

Fantastic. I have the same engine but can't even source the parts. CDI, magneto rotor, for example. I wish I was born there. I would pay you to work on my Estrella

[@M.V.1]

Beautiful. Very good works. 👍🏻👍🏻👍🏻🇮🇹🖐️

[@misterwoodl]

a genius bike 👍

[@Q.L.Engineering]

Thank you.

[@joerggrossmann5375]

Great Work !

[@Q.L.Engineering]

Thank you, Sir.

[@-_-PUM_PUM]

Очень классный подход к работе, не подскажите какой САПР программой пользуетесь?

[@Alexander_937_]

на pro engineer или creo похоже...

[@artisanbp]

Отличная работа, мне захотелось повторить вашу работу, можно у вас заказать руль, сидение, крыло?

[@pat-ko8888]

Thanks for watching, thanks for die Arbeit

[@Q.L.Engineering]

You are welcome, Sir.

[@riptwan]

Nice, doing a sympathetic resto on one currently

[@Q.L.Engineering]

Thank you for the friendly feedback, Sir.

[@kalebjayden9744]

How can I contact you?! I am looking for such modification on vintage motorcycles.

[@Q.L.Engineering]

Hello Kaleb Jayden. You can contact me via [e-mail]

[@АлександрНовоселов-ж3т]

Спасибо за видео,молоток!

[@Q.L.Engineering]

С удовольствием. Приятно, если понравилось. С уважением S.v.S.

[@jameswithey8536]

The Ton mate!!!

[@Q.L.Engineering]

💪🏼💪🏼💪🏼👊🏼☄️💥

[@milanzdrahal5691]

1000% 🛠️

[@Q.L.Engineering]

Thanks! 💪🏼🤟🏼🤟🏼👍🏼

[@arturasstatkus8613]

Vundeba👍👍👍👍👍

[@-_-PUM_PUM]

И как рассчитывали шатун

[@Q.L.Engineering]

Google Translator says: Привет. Программа САПР была студенческой версией устаревшего программного обеспечения, название которого я не хочу здесь упоминать. Если бы мне пришлось сделать это снова, я бы использовал SOLID Works или NX. Шатун был рассчитан по методу аналогии и сделан более жестким. Все поперечные сечения валов на 30-40% больше. Кроме того, толщина стенки глазка значительно увеличена с целью большей эластичности титана и за счет гнезда.