Scooter dies when i stop - Help

[bahiano]

Dear all,

did anyone else have this symptom? My 50 cc 4-T Super 8 has only 1000 KM on the meter and always dies
whenever I have to stop somewhere. I tried everything like cleaning the carb, checking vacuum hoses,
Valve clerance, Spark Plug. Even if i higher the idle speed, it will fall again automatically, air/fuel screw is put to factory adjustement.
This happens only when the engine is really warm. No other symptoms so far, it
runs smoothly until top speed. I am guessing it could be the CDI… but I am really going crazy  as warranty period is
also over…
Any help would be highly appreciated...

Sorry for the mistakes as I am from Germany 

[thebatman]

  This may be a long shot but it sounds sort of like the "choke" is still on and richening it to much...(the auto-enrichener) or that the pilot system in the cArb is partially closed.. Check the pilot jet,etc. again

[bahiano]

Thanks a lot, i will try it.
Today i will replace the CDI and see if it will do the trick. Otherwise i will have to start all over again 

Cheers Markus

[bahiano]

Hi all,

the CDI unfortunately did not fix it.

@batman: What do you mean by pilot system? Sorry my english a little poor  The jets i already cleaned....

Any suggestion is welcome...

[JustWantToRide]

I believe he meant the pilot jet in the carburetor.

Do you have the service manual?  Section 5 starts out with instructions for testing the auto enriching circuit.  If you haven't tested it - then that is what I would look at.  The manual calls it a "bystarter".  Once you get used to the odd translations - then the manual is very helpfull.

[bahiano]

I already changed the auto-enrichener, still the same problem...
Thanks so much anyway

[JustWantToRide]

Da passiert es nur, wenn es heiß ist - ist es überhitzung?  Die Lüfter laufen?  Wie funktioniert die zündkerze aussehen?  Ich denke, es läuft zu reichen, und die apark plug wird dunkel.

[bahiano]

Yes, it only happens when engine is hot! Fan is working... I check the Spark Plug, looked ok so far...

Dein Deutsch ist sehr gut 

[bahiano]

i cleaned the carb again, tested the auto-enrichener, changed the spark plug (the old one looked quite dark).... Still i could not
adjust the carb, idle cannot maintain and it dies again  I even checked ignition system with the Ohm-Meter, everything ok as per manual values....
Ok now i am done and dont know what else to do
Any ideas? Feel like givin up and selling it 

[JustWantToRide]

Vielen Dank, werde ich nicht mehr in die Praxis meiner Deutschen viel mehr.

Es läuft zu reichen. Öffnen Sie das air box, entfernen Sie den filter, und stellen sie sicher, dass sie gar nichts blockieren die Luft. Starten sie ihn mit der airbox noch offen und keine filter.

Wenn es läuft - dann prüfen, ob die filter ist erstickt - oder wenn der vergaser es stranguliert.

[bahiano]

Ok vielen Dank, werde es morgen versuchen...
Thanks and Gute Nacht!

[bahiano]

Ok i tried as you said, it seemed a little better, it did not die, but i could not adjust the carb the same. Idle speed only raises when i close the air/fuel screw, or when i
nearly reach the closing point. What can that symptom be? I thought it would no run at all with the air/Fuel Screw closed 
I think i will bring it to the dealer and let him go crazy with it

Cheers Markus

[JustWantToRide]

I could be a weak coil - but I would think it would not idle with a weak coil. 

It isn't able to burn the fuel it is getting.  I think you have missed something in the carburetor.  Either a jet is clogged, the needle is in the wrong position, or the float is not adjusted properly.   

[bahiano]

ok i think i will try to get a new carb... is the one with the "metal top" in ebay ok? Are they all the same? We can get them here in eBay quite cheap for
chinese scoots...

[bahiano]

ok i cleanes all jets again with air and they are all clean. Still the same symptoms, i cannot adjust the the carb, when i close the air screw, the idle speed
raises instead of dropping... there seems to be a change only when closing the air screw opening it, no reaction from the idle speed....
I am no really out of things to try... 
Thanks everybody anyway...