Bad running motor

[Yvan]

Hi,
I am new here and have a question.

The previous owner of the 101S scooter did not run it for a few years. After cleaning the gas tank, carburetor en replacing the sparkplug, it is back alive. I experience the following problem:

The scooter only runs good with the throttle full open. In de midrange the motor is jerky and has no power. When I go from full throttle to zero, the motor stays on higher rpm’s for a while before it slows down.

Any idea anyone?

Thanks in advance
Yvan

Sorry for the mishaps in the spelling, English is not my mother tongue.

[harry]

The scooter only runs good with the throttle full open. In de midrange the motor is jerky and has no power. When I go from full throttle to zero, the motor stays on higher rpm’s for a while before it slows down.

hi Yvan welcome to the forum...

clean the carb again!  use compressed air .
pay careful attention to the choke passages.
you might want to check that the auto choke is working .

and BTW you don't need to apologize for your english, its just fine, along with
your  spelling  ... i get emails everyday  from people born and "educated" here
that are far worse by any standard..

oilyhans

[harry]

How to Test a Auto Choke
Poor starting and an increase in fuel consumption are possible signs that the automatic choke is not working properly.
To check that the plunger (needle) is not seized or stuck do the following:
1. Remove the choke unit from the carburetor.
2. Measure the protrusion of the plunger from the body (A-B distance)
3. Use jumper wires to connect from a 12v battery to the choke terminals, keep it connected for 5 minutes.
4. Measure the distance between A and B again.
5. The plunger should have increased in about 3 to 6 mm.
6. Do not attempt to disassemble the unit, it is not serviceable. If is out of specification replace the unit.

[Yvan]

Thanks for the quick response, Harry. I will have oily hands this weekend. 
Greetings from Belgium.
Yvan