I got my father's first CZ250 sport in my garage. He passed sadly, so I promised him the bike would come back to life and Imma ride it forever. Can't wait to be building and developing my own engine. I might go for an I2 layout and make it a crossplane.

Glad to see you back to it.

I should be asleep now, it's 2.30 am, your craftsmanship is beautiful so im going to keep watching. Thank you. 😊

I love all the work. Who would though that somebody try to make Jawa actually usable 😄. And the wheelies are amazing!

Krásná práce😊

The Jawa 350 & CZ 250/305/350 twins always needed a 5 speed gearbox, as it was very easy to redline the engines in 4th (top) gear. The only solution I found was to change my tuned 1976 CZ 350 motor's sprocket ratio from the stock 16:52 to 19:52 and replacing the original 13 tooth output sprocket shaft with the later 1978 CZ 250's 14 tooth version. Another issue with 1970's CZ350's is that of one identifies and removes all the restrictors limiting the power output to 22 HP @ 5,250 RPM, one soon discovers why they were installed when the increased performance rips the weld apart that attaches the bolt to the chain adjuster, also bending the swing arm chain adjuster lug.

A lot can be learned from your videos. Kudos to you for your effort, knowledge and care for every detail. Very interesting content and channel. Greetings from a Jawa driver

Fantastic work, lovely to watch. Wish we had more riding in the end, it runs so sweet!!

Awesome work!

New follower, nice machine work. I'm a machinist too and only a hobby moped tuner. I have a Tomos engined moped so I feel you when you need to make parts for yourself! :D

Buen trabajo, esa moto es una belleza

Шикарно!

Hi, this working is perfect congratulations 🎉

Woow 😍... such a great video ❤❤

Great work 😍😍😍 i am from india..

👍

Great video. Reminds me of the days I designed 5 speeders for racing outfits. More tricks in gear making than meets the eye. Just one question. What sealant did you use?

Crazy 👌👌

"There's not much out there can beat a well sorted Jawa" Overheard, 1970s

Well that got technical.. 👍

I want to build a bike with a snow ❄️ sled engine on it, possibly use a gear box from a CBR 750-1000 or so, maybe find a damaged case cut the engine away from it, and weld up the gap, use a chain or belt to connect the two, a CVT between the two maybe interesting. It would likely need to be limited, the wide gear ratio difference isn't needed with 5-6 gears . Having the option to throttle and GO🤜, would be cool, if it could be managed, the ability to lock out the CVT variable drive ratios. Ot click into 4-5 gear and throttle and go! Anyway, a decent size engine, 440cc +, with expansion chambers. And a chambered muffler, kind of a cross between a muzzle supressor and a performance car muffler on a miniature scale. For a some what quirt engine, while maintaining flow. Possibly creating a low pressure to scavenge the cylinder, start by splitting a decent wall thickness of 2.5' tubing, possibly flatten it out a bit. To about 1.75-2.0" cut out bulkheads, for chamber walls, with. A hole 1/4 the distance from the top, saybits 2" x 4.35" tube the hole center being just over 1" from the top. With the exhaust tubing being approx. 3/4"-1" drill out the holes, use a press to dimple the holes . Creating sbout a 1/4" dimple so the hole flows with reduced eddy currents. Weld a 2" long piece of tube, that the expansion chamber will fit into. To one of the the plates. With the dimple being 1/2" larger than the hole. The exhaust inlet be ring welded into the dimple. Possibly make it a cone shape and bore out thr hole slightly. Weld in the exhaust tube plate to one side of the 2.5" (or 2"tubing) and align all the otherplates with the dimples pointed side about 1/8" from the flat of the next leaving about 5/8" to 3/4" from flat to flat of the plates. With the 2"-2.5" tubing being about 12"-16" long and the final plate having approximatelyg 1" tube with a slight recversed funnel shape to it, going from 1¹/⁸" to 1" as the outlet. The final 3" bring a chamber with a 5/8"-3/4" tube running from the chamber back to the inlet disc with 1/16" Holes drlled on 1/2" centers. Then fill the chambers with ceramic wool except for the last 3": chamber, the remaining half of the tubing, gets a series if 1/8" hole drilled where the plates fit ?to allow the plates to be plug welded to outside tubing. To keep the disc secure without rattles. The exhaust should flow freely, with reverse flow being very poor, it should flow as if it were a check valve. The final chamber should create a low pressure to scavenge the tube, the hole filled to tube should add a deep tone possibly add two additional 1/2" tubes. This also relives any pressure in the chambers. The aluminum material should should also keep the sound inside the muffler. The frame , built similar to the 70's street and trail. Only built from aluminum. With a modern mono shock in the rear, with a tubular swing arm. Fabbed from 1.75" tubing with super moto spoked rims powder coated a brass,/bronze color with black spokes. The forks matching. With a black frame. And with brass swingarm. Carbon fiber fenders, an aluminum fuel snd oil tsnk, with carbon fiber cover to simulate the fuel tank. And theseat being a flat cafe style with diamond tuck stitching, a micro fromt farring and headlight. With a pair of projector, with LED's and a center hi/low headlight the normal headlight being a running light, the high low projectors bring both bright or high beams. Running light / normal low beam ,then norml high beam. Then the added projectors being 160 watt leds in two colors daylight white, and ice blue white, the normal headlight having a amber hi/lo, and daylight white, with the switch allowing either normal headlight or projectors cant be off. But they can all be on. With a pair of small projector driving lights at the bottom of the frame. In amber to operate as fog lights and the whole backend of the seat and a 1" thick strip under tge fender being stop /tail and turndignals with the license plate mounting. On the swing arm under the muffler it bring just above the rims axel. The muffler outlet simulating a 1.75-2" outlet and quiet for a screaming 2T! Even a 440 would be awesome. Port it a bit, get about 2k rpm from it. Possibly add a supercharger and efi. Attempting to keep it the size of a 125-250 cc,with a much lower suspension the belly him height barely higher than a CBR, with 17"-18"rims and 240-260 rear rim 160 front. And gauges above the headlight and possibly clamp on's sory to ramble, i have had this in my mind soo long, im about ready to sell it and buy something else!😅, either a snow sled engine or a Ninja engine about 600 - 750cc no largervthan a 900, the 2 cylinder is the reason for ninja engines. Even a 250 ninja would be cool in a super moto style bike. A semi super moto meets a cafe bike. Something light and somewhat small but definitely not undersized or underpowered. What kind of power could a supercharged 440cc 2T EFI engine produce at .8-1 bar boost??😮. Have a great day!

👍👍👍👍

это просто нереально круто - привет из России

Keby takýto ľudia pracovali v jawa od začiatku, nemuseli by teraz made in china motory dávať a boli by jednotka na trhu. Skvelá práca od začiatku po koniec 👍👍👍

А вы не делаете тюнинг комплект шестерен для Явы 350 634?

Any gair box For sale price please gair

Ostra 250 🤌

21:56 why u changed the exhausts

Oooo original škoda gear hobber, might be equipment that cut the original gears just the operators are more motivated. :D

what is its maximum speed?

Weren't you thinking about 5 speed gearbox?

I think, that JAWA need 5 gearbox.

FİNALLY

české ručičky v praxi

was sagt der tüv dazu ? 🤔😂