Jawa / VVM [dieselmaster]

[vincentyeager]

Hi all,

firstly: i wanted to wish everyone a jolly ol' christmas

the rear brake fixation rod turned out be sitting too loose around the rear fork.
therefore decided to go in the more original way, like a Jawa normally has its rear brake ankered.

rear brake anker

rear brake

the chain tensioners are kept original.

and the koni spring adjuster. damper adjuster is on top of the spring.

[vincentyeager]

Because the rear brake/hub is not jawa anymore, but kawasaki (250), the chain casing didnt fit well no more.

the tunnel, to accomodate for the rear fork therefore, has to go.

kettingkast oud

you can see some scratch marks from turning the rear wheel, made by the sprocket bolts scraping the surface.

with the help of a paper template, cutted out a new piece of sheetmetal.

kettingkast nieuw

mark the gap is evenly all around, ready to fill with tag welds.

[vincentyeager]

Here is another new sophisticated piece of VVM work, the (6*** aluminium) front brake disc spacer;

from scratch on the laith

set, shiny and done


This bike woulndt be worth the 'racing' in VVM if it would never see a circuit, better be well prepared;

and finally, the overal front-end;

[vincentyeager]

It appears that a diesel engine dictates the need for a separate dieselpump overflow fuel line, in order to keep the pump from surging (leading to inconsistant idling/running of the engine).

Jeroen (from VVM) soddered a brass 6mm (about 1/4'' O.D.) line, that practically runs to the top of the tank.

in the meanwhile i've painted it again, and we are now working on the front fender.
Jeroen has hand beaten/rolled one out of aluminium (or 'aluminum' as they say in the united states of 'bankrupcy').

to be continued.

[alexanderfoti]

Looks good. I had the same problem with mine, I ended up running the injector leak off back to the fuel supply line with a T

[vincentyeager]

Looks good. I had the same problem with mine, I ended up running the injector leak off back to the fuel supply line with a T

we wanted to do this as well, since the tank was already painted.

however with a T, you could run the risk of getting the mentioned surge, air bubbles that circulate through this by-pass all the time.
so we did it properly just to be ahead of this possible issue.

[alexanderfoti]

Looks good. I had the same problem with mine, I ended up running the injector leak off back to the fuel supply line with a T

we wanted to do this as well, since the tank was already painted.

however with a T, you could run the risk of getting the mentioned surge, air bubbles that circulate through this by-pass all the time.
so we did it properly just to be ahead of this possible issue.

That is true, I had this problem.

Luckily, due to my pipe layout, any bubbles make their way back to the tank, its kind of a double U layout.

[coachgeo]

There are inline fuel filters for petrol vehicles that have a third port. In, Out and Out. They are used to bleed fuel vapor back to the tank to prevent vapor lock.

would suspect one could put one of these inline with the IP / Injector bleed fuel line before you "Tee" it to the fuel feed line. Mount it so it the bleed OUT port is the upper most port so air will bleed up and out of it. Run a tube from this into top of your tank as alexanderfoti did or heck even to top of your Fuel cap like the old Dirt bikes did.

[vincentyeager]

We decided to use an original diesel dynamo, below you see the reworked and assembled flywheel to accomodate for it.

A side view of the bike with the dynamo flywheel fitted. The belt groove on the outer side is now free for other things

[vincentyeager]

Here we see the primary chainwheel being reworked to fit on the diesel crank;

and the primary duplex chain fitted on the bike;

as the chain is now longer, Jeroen made it by joining two original jawa chains.

[Tetronator]

Man, that really is beginning to look good... Kudos.

[alexanderfoti]

Agreed, looking excelent. Very good attention to detail!

[vincentyeager]

Here we see a glimp of the revised electrical system, whereas Jeroen made a whole new ''cable tree''
The battery still sits in its original housing.

And the side view upon the delrin fusebox that Jeroen made.
He has divided the electrical system into four as displayed.

And here we have the revised throttle system, because we added the shut-off solenoid later on.

[vincentyeager]

the exhaust system with megaton damper;

do take notice of the finished engine cover;

[vincentyeager]

Here we are measuring the point of injection

with an angulair measuring device that Jeroen designed, and produced himself.

[vincentyeager]

Good news and some other news;

The bike has made its maiden ride and we are now handling the 'child deceases'.

It turned out that the kickstarter wasn't able to start de diesel, for its not a four stroke kickstarter. It's lacking stroke.
So ordered a brand new dieselengine with an electric starter, because pushing the bike was a total crime. yeah we've lost a few stone there.

Because the electric starter sits in front of the engine, and the jawa vvm has slightly a longer assembly than you'd have with a (comet) vario, the front end had to be changed almost fully. The frame also abit.
A kawasaki kz750 fork was fitted for it has an offset front axle. Yokes are still paoili, however Jeroen reworked the holes from 35 to 36 mm in diameter.
Caliper of this fork replaced the brembo, and the guzzi disk was changed for a gsx1100 disk which is now on the other side. Brakes well and linear. Pump's still brembo.
The fork had a WP rebuild but still needs more adaptation to make it more sporty. After all a kz is a semi chopper. The Jawa isn't (a worn out flying carpet). It does must impress when challenged by crotch rockets. Even when not challenged at all.

The frame tube we've made on the right side, had to go in order to make room for the electric starter. Jeroen solved this by having the dieselengine make part of the load bearing frame. stiffness is still good.

Than there's the dynamo/stator of the dieselengine, for we've let the flywheel be as is on the new engine (need the starter teeth). We know u guys have little issues with the stationairy character of it, in combination with a vario, but the Jawa VVM doesn't have a vario.
So Jeroen rewound the copper spools (increasing the amount) and it now always charges the 14 ah battery. Obviously the battery is now more important for us then it used to be. And alot bigger too.

Also the primary drive is changed by Jeroen (small sprocket), from a spline which kept breaking (when driving off in fourth gear dieselbike only ) to a conical friction-like connection.
It has a conical sleeve so the crank can stay as is.

last but not least, the hand beaten and hand rolled aluminium front fender made by Jeroen (VVM) as well, check it out;

[Tetronator]

Looking good Vincent! Hope to see it on the road soon.

Are you building it at VVM racing in Spaarnwoude?

[vincentyeager]

Indeed Jeroen is situated in the idyllic village of Spaarnwoude.

[Tetronator]

Sweet, that's really nearby for me. Might come over and take a look at it! If that's OK of course.

[Tetronator]

Well then, I went to see the Dieselmaster today at VVM Racing and boy does it live up to its reputation. The way its built and put together looks like it could've come from the Jawa factory itself and the bike is not even done yet! We can expect to see a really well build machine coming from Vincent and Jeroen. Its even going to be featured in a dutch motorcycle magazine called "MotoPlus". Jeroen also told me he accepts custom machine and/or build work for other diesel bike builders, at the moment he does a lot of custom machining for bike builders in the Netherlands and has shown me some impresssive work pieces.

I had a good chat with Jeroen and was impressed with his work, and finally got a place for me to get the machining done for my build...

[vincentyeager]

Today we finished the bike, ready for the state roadtraffic test.

proud owner;

while driving i realized what 'the big knock' means.
this really is 'big knocking'. 'turns more heads then a harley'

greetings fellow bigknockers.

[Tetronator]

Congratulations on finishing it!

Now lets hope the RDW people aren't to harsh. Looking forward to the motoplus article and seeing it on the road.

[alexanderfoti]

Really looks to be an excellent build!

[coachgeo]

really sweet. Much congratulations.

[Dan J]

Absolutely beautiful bike

[pietenpol2002]

Very very nice work. And can't wait to see your next build.

[Bj-torb]

Nice work. Look forward to see a video of it running

[vincentyeager]

Thanks lads

I hereby present you this sneak preview;

https://www.youtube.com/watch?v=FfhL43AcSLg

ps. top speed thus far; 97 km/h

the speed-o-meter's precision is 1 km/h

[coachgeo]

look forward to your report of its comfortable cruise speed

[Eddy Wane]

Very impressive. It has that Café Racer look.