Hi all, i used the search function, but can´t find the answer.
Due to my 3 years attempt to get the bike running smooth, i already replaced every mechanical part, so the last remaining suspicious thing is the VAPE, i installed long time ago. Bike at decelleration is bucking and under constant driving, it sometimes rattles, like a marbles in a can. To crosscheck, i bought a complete used engine with nice looking ignition and flywheel. Mounted it to the bike, set the points to 0,35mm connected a bulb to the black wire, then a battery, then cable to ground.
Didnt see any change in bulb light intensity.
Also no spark, connecting the black wire to the ignition coil.
What could be wrong ? Did i mix-up, the motor could spark, just connecting the black wire to ignition coil?
Is it possible to check resistance of the both ignition coils, while soldered as they are?
This bike drives me crazy, but to beautiful to sell it
Is it possible to che

Clean the points.

Not sure where to start after reading that.
Man you've not been having a good time of it.
When you said bucking & stuff i though i was reading a 400 story.
Ball bearings clanging around in the head sounds like very lean detonation--but why--is another can of worms.
Anyway, as MarkT said, clean points & see if she sparks then runs--then start again & see how it performs.

Thank you very much for your input.
Sorry, took me some time to check you suggestions

Unfortunately still no spark, after cleaning the points and replacing condenser.
All cables on stator seem ok and have no connection to ground
Tried with 2 different ignition coils.
What i am worrying about
- Is there a way to measure resistance of each coil on the stator plate ?
- am i correct, connecting black wire to ignition coil should be enough to get spark?

Would really like to ride it the last remaining weeks of the year with good weather 

Welcome back. Yes black straight to the coil.
Try using an analogue ohm meter to the black, & as i understand it with points closed you should have Zero & points open should show--something--not zero, maybe just under 2 ohms. MarkT knows the answer to that. I guess a digital meter should still show zero when closed--i'll have to catch up with this modern stuff. Just saying first get a reading like that & if it stays showing as open [or closed] constantly then go look at how the points wire is connected so its insulated & not to earth under the fiber washer. & that the small circular piece is in where the points wire bolt passes through the points steel piece. That would cause it to read closed all the time ie zero. If reading open constantly in theory they can't be contacting when shut. She's a mystery this one. Could you go back to the Vape system & time it up & try again.

Are you using HT coils for inductive type ignitions? Try connecting a volt meter to the ignition coil feed wire, kicking the bike over, and seeing if you have volts, then no volts, as the motor turns over. If you do, then it should spark with the right HT coil.

Wessi, 

You should be seeing a change in resistance on the black wire with points open and closed.  You'll need an ohmmeter with a "Rx1" scale.  The old fashioned analog meters with the swinging needle are best for this test, sometimes digital meters will work.  Or many times it's hard to get a good reading with a digital meter.  Rx1 scale is important. 

Points closed should have a reading of 0 ohms with one lead of meter connected to black to points and the other to a good ground.  With points open, the reading should be about 1 to 2 ohms or so... this is basically the resistance of the stator source coil.  Test is done on black wire with it disconnected from ignition coil.  (My DT250b measures about 1.6 ohms with points open. Exact reading can vary a little but should be in the range of about 1 to 2 ohms...  I've seen around 2.5 once on a bike that ran well. 

Just a thought & doesn't matter [but correct me] if you're testing into the black still connected to the plug coil does it double the resistance pretty much seeing plug coil primary is guessing about one ohm. Same end result though between open & closed--closed being zero.
Edit--with ignition turned on of course so it's not all shorted out. Someone 'did' test like that back a few posts i think.
Only thinking 'that' because DT1's had a branch wire off the mag loom to hook a meter too, so the loom would be still connected to the plug coil. Or am i just being too smart for my own good lol.

Not sure that a "VAPE" is a CDI type ignition or not? If it is, the HT coil isnt likely to work with a points system.