DDK - Die Deutschen Klassiker

There’ll be enough of it left for the nightmares to continue.

A blast furnace is required and a brain transplant.
Never have I done anything so bloody annoying as this French bike.
I want to do another Honda, infinitely better and then some.

911hillclimber wrote:A blast furnace is required and a brain transplant.
Never have I done anything so bloody annoying as this French bike.
I want to do another Honda, infinitely better and then some.

They were designed and made at a time when Most of Europe was completely broke and for anything to sell it had to be super cheap. It was the same in the U.K. There were hundred of rotten two strokes available and luckily most have decomposed now.

Not one to give us on these things...

Made some progress today.

Tried various timing setting using the small new carb off a Chinese something or other, around 50cc engine.
It has never run or even popped or farted with this carb, but it now regularly fires on kicking the engine over and several times has run for over 8 seconds!

I tried 3mm BTDC and to 5MM BTDC, 5mm being the spec from Magneto France in the day.
Changing the timing makes no difference at all, so it is now at 5mm btdc.

I have changed the jet hole (there is only one jet) by soldering up the jet the carb came with and using my range of BOC gas nozzle cleaning wires to set the fine hole.
The finest is 0.36mm dia.

The engine is so very close to running correctly, just not close enough, but progress!

As to post war quality across France and Europe? Guess all countries struggled to do the same as Terrot, BSA most notably, James, Villiers in general etc.

To be fair the bike as a whole is quite well done, just the car is crap.

The carb is a French made AMAL, a very British Carb!
Fingers crossed for Sat at the bike show autojumble.

Best of luck!

Crap show.
Won't go again.
No parts.
Tried to start the engine this afternoon to vent my frustration…
No start just the usual burps and a few seconds running.
miffed off with it, cannot think of what to do next except break the bike for parts or sell for a low number to one who likes to tinker.

How low a number do you have in mind...

Last year I tuned down £1750 as it stood back then with a very non-starting original engine.
I guess (stopped counting now) I have 2 x that in the bike.
It would be sold with this engine/carb re-installed.

Going to try one more action on the carb tomorrow if my lathe can machine finely enough.

The engine floods and I need to stop that first before getting into finer detail.

911hillclimber wrote:Crap show.
Won't go again.
No parts.
Tried to start the engine this afternoon to vent my frustration…
No start just the usual burps and a few seconds running.
miffed off with it, cannot think of what to do next except break the bike for parts or sell for a low number to one who likes to tinker.

Set fire to it!

TOO rare to do that and it will still be a heap staring at me! Mind you with Nov 5th looming might be an opportunity!

Nice winter project for another tinkering home mechanic aged over 65 I think, wives would love it, husband tucked away for endless hours in the shed, wait! That's me!!

All very frustrating but it has to be fixable. Have another plan for today.
My custom hi-tech engine stand has made the thing very easy to allow working on the engine and getting a comfortable kick start action when on the floor.

Tried to modify the original carb to stop it giving a hugely rich mixture that is killing combustion.

I soldered a thin cover of brash sheet over the top of the nozzle and drilled it 3mm, the diameter of the nozzle tube in general (the hole the needle moves in).
Tried several needle diameters but not a noticeable improvement, just a few firing combustion cycles and dead.

So, went back to the 50cc carb from China for £7. The throttle bore through the body is small, even looks too small to common sense but it is rated for 50cc to 80cc modern moped engines that probably rev way more than this 1950 lump from France, so I think flow might be OK.

Anyway it ran. Started quite easily (10 ish kicks) and no choke.
It ran for about 30 seconds and gave the occasional backfire through the carb and out of the exhaust port in the head the latter scorching my jeans. Combustion was not even but it kept going and then stopped. It had run out of fuel.

I reset the timing of the magneto to 3deg BTDC (was factory spec 5mm). Many many modern 2 strokes use 3mm.

It started and ran again, a bit more evenly and with no backfires, again for about 20 seconds, seemed to run about a month in comparison to last week.

Bit late on a Sunday afternoon with an unsilenced motorbike engine farting about so called it a day until this coming week when all are out at work.

Feels a massive step forward, but, always a but, the engine does not throttle well. It is unresponsive to the throttle to the carb and would be un ridable I think.

Now, could this be the bore diameter being too small?

I have the copy Dellorto to try again, and this has the same inlet/outlet bore dia's of the original.

During these runs the compression 'feel' on kick over feels far better which can only help.

Been given permission to sell at £1750 if anyone really wants it.

Backfiring through carburettor suggests a weak mixture (retarded ignition) or cold engine weakness. I’d say you’re close with the Chinese device. Presumably it’s designed for an 8500rpm and the vicious frog 5000 max.

Not sure!
But they seem to rev to a 1,000,000 rpm as they frantically wirrrrr to 30 mph!

I've advanced the ignition to 3mm. If this works well enough I will try the big (by comparison) Dellorto.

A year ago it actually started 3 times with this carb, 3 times in about 50 attempts, so not holding my breth.

I know to the same design of bike running in France with this Dellorto design, but she has to bump start the bike, it will not start using the kick.

By design, the number of revolutions you can get with every kick is only 5 or 6 depending on how angry you are with it. I can get it to spin a lot more than that!

My Monet & Goyon started by paddling it along with your feet - which is what most owners do/did. The kickstart was almost a cosmetic item more than something functional.

Not sure if this has been covered earlier and frankly I cant be bothered looking but does it have the correct piston fitted?
This is absolutely paramount for the port timing to be correct.
As a slight aside you would be far better to keep plugging away to get it running correctly as they are a labour of love and worth less than half of the equivalent British bike.
Best of luck!