Jawa 350/639 final engine mounting Part 2 (NO Guide)

This is the 7. video from a series of Jawa 350/639 engine renewal videos. This time we are going to put the whole engine together and move forward to the motorcycle chassis. Please note:

THIS IS NOT A GUIDE ON HOW TO DO IT!

Toto je 7. video zo serie o renovacii motora Jawa 350/639. Tento krat zmontujeme cely motor dokopy a premiestnime sa k ramu motorky. Prosim berte na vedomie, ze:

TOTO NIE JE NAVOD AKO NA TO.

Video after:

Engine into the frame and Start

Videos before:

Mounting deadmass compensating panels

Removing the crank, comparison btw. serial and sport crank

Dismounting pistons and cut the engine in halves with a selfmade tool

Dismounting primary gear and clutch

Dismounting some basic parts, cleaning the engine

Engine out of frame

#motorcyclevideos
#motorcyclerepairing
#motorcyclerestoration
#motorcyclerepair #jawamotorcycles
#motorcyclemaintenance
#motorcycleromance

[CZtuner]

7:02 Securing the gear shifter pawls (pegs) with cable zip ties will make it easier to insert the mechanism. Once the mechanism is in place, cut and pull out the cable ties with pliers. Makes the task a 10 second job.

[CZtuner]

11:50 For the past 40 years, I've always used a piece mahogany placed across the right hand case and drifted engines back together using a lump hammer.

[juergenfreiberger]

1a Arbeit ! Mir sind in den frühen 80ern im 360er mit 1:11 und 30er BVF oft die beschi..enen Pleuellager und Blech- Schaltgabeln verreckt,
heute nat. kein Problem mehr.
Mit den originalen Töpfen war nix zu gewinnen, mit denen von 150er ES / TS ging die Post dann richtig ab, 250 Emme im 3. kein Probem
und das im -schweren- Pannonia Fahrwerk zu zweit.

[CZtuner]

27:40 WRONG!! Carb manifold MUST be attached and bolted into place on both cylinders BEFORE tightening down the cylinder heads, otherwise the carb manifold will not sit correctly with the cylinders and cause the carb manifold gasket to fail, allowing (false) air to leak in.

[martinhudzik]

Po osadení hláv ich len zľahka dotiahni, namontuj prírubu karburátora, s válcami sa bude dať hýbať ( určite bude pasovať aj tesnenie 😀) a hlavy dotiahni.

[CZtuner]

6:20 if the gearbox keeps destroying the 4th gear selector fork, it is caused by this bearing being misaligned & damaged by riding the bike with an over tightened chain. The only remedy is to change the bearing otherwise all replacement selector forks will also be destroyed within 100 kilometres of riding.

I've repaired 9 engines with this fault.

[CZtuner]

34:00 Not a legend but fact!! The original 1986 - 1987 Jawa 350-638.0 produced 34 HP @ 6, 500 RPM (redline at 7, 000) and was capable of 155 KPH / 95 MPH fuelled by 99 RON leaded petrol (9.2 million calories of energy per litre). I've owned a 1987 638.0 and a friend owns two 1986 638.0 at the moment. Modern 98 RON E5 unleaded petrol contains only 8.5 million calories per litre so obviously they don't perform as they did in the past, but they're still a lot faster than the later restricted 638, 639 & 640 models.

[MiraHusqvarna]

Je to tak napřed dotáhni přírubu karburátoru a pak dotahuj válce a hlavy jinak ti to bude dělat problémy, jinak pěkné video.

[TomBartram-bc]

Hi. Have you come across this problem? On my 2015 Jawa 640 oil is leaking from the gear box and collecting in the compartment where the gear box sprocket is. Some of it is entering the chain case too so at least I have a well lubricated chain! I've changed the the sprocket shaft seal and neutral switch seal to no effect.
It'd not a huge amount but annoying all the same Does oil leak around the clutch pushrod?
Any ideas? Thanks.

[CZtuner]

6:15 Jawa 250-623 & Jawa 350-633 engines don't feature the bearing securing washer & screw. It didn't appear on Jawa engines until 1976, along with a few other internal evolutionary changes, on the Jawa 350-634 engines.

[grahamfrancis]

Can anyone tell me what PSI I should be getting on a compression test? I did a test on my engine when cold and I’m getting 130 PSI on the left cylinder and 135 on the right. I’ve done a bit of research on line and it’s hard to get an answer. It seems that two stroke twins typically have 170 + PSI, so I’m guessing that if it’s similar for a 350 twin, my compression might be a bit low

[CZtuner]

12;48 Before fitting the pistons, derestrict them by widening the skirt openings so that the transfer ports are completely open when the piston is at TDC in the bore, as with the original 1986 34 HP & 6, 500 RPM 638. After 1987 the engines were restricted down to 25 HP @ 5, 500 RPM via the piston skirt openings being narrower (partially blocks 2 of the 4 transfer ports at TDC), shorter silencer bodies and restrictor collars on on the baffles (no gasket collar at the tail of the baffle).

I've been derestricting 638 engines for decades.

[grahamfrancis]

These videos are very, very good. Thank you! I have a 1986 638 TS350 that has a problem with hot starting which after checking every possible cause, I am thinking that the problem is due to lack of sufficient vacuum to suck through the fuel/air mix into the crankcase chamber. I can get it started by removing one spark plug and pouring some neat fuel inside. Someone has said that the problem is most likely to be the centre crankcase oil seal, but I cannot work out from these videos whether there is a centre seal or not. If there is no centre seal, I am wondering how the fuel/air mixture in one crankcase cycle does not escape into the other, or alternatively, there is not enough 'fuel/air charge' sucked in through the carb to enable combustion. i don't want to strip my engine down unnecessarily if the problem is due to something else. If you are able to help with any suggestions, that would be great :-).

[tombartram]

I got a 7 year old Jawa, engine never been touched. So I've got this shit still to come. Oh gee. So much bloody work. Should I add extra oil in the tank or trust the factory setting on the oil pump?

[kirillpaliev]

Добрый день. Почему не грели картера??

[jozefbircak]

Hm, čo dodať?
Ako som to už spomínal, videl celý seriál.
V podstate demontáž je jednoduchá. Cielené násilie dovolené.
Montáž ma zaujala, už len preto, že cez leto som absolvoval.
K tomu nahrievaniu:
Ja som dal do mrazničky, ale kartre som zohrieval teplovzduškou.
A neseklo ho pri vkladaní.
Druhá polovica bola zaujímavejšia.
Nesťahoval som, ale tiež nahrieval.
Detaily nebudem rozpisovať.
Inak sú tam nejaké komenty na motoride.sk, v príslušnom vlákne.
.
Farebná kombinácia tituliek je príšerná. Príliš sýte farby, nečitatelný výsledok(slovenské)
Bude aj test drive?

[CZtuner]

DON'T USE SILICONE SEALANT IF THE ENGINE WILL BE USING ETHANOL CONTAMINATED FUEL (E5, E10, etc.)!!

Ethanol dissolves silicone around the crank bay very quickly and will cause a leak to the gearbox, outside air, etc.

Always use sealants stated to be ethanol resistant, such as Blue Hylomar. I've had to rebuild many Jawa & CZ engines because ethanol had dissolved the silicone sealant around the crank. CZ singles are affected the worst and will burn all the gearbox oil out through the crank. I've had 3 x CZ 125 engines, rebuilt & sealed with silicone, start burning gearbox oil within 200 kilometres, when E5 was first introduced in the UK. It took a while to figure out what was happening.

[pazdzior]

Bardzo dobra robota:) jak się nazywa taki zestaw do jawy, czy to Pana autorski projekt pozdrawiam serdecznie

[سلاممحمد-جر]

هاي. هل موجود. بساتم. مال الجاو. ردلي. خبر. رجاء

[سلاممحمد-جر]

هل موجود. جميع. أغراض المحرك. ردلي. خبر. رجآء