Agility 50 big problems

[Jukka]

Kymco Agility 50, 2006. Reason of engine fault we make big renovation.

We replaced cylinder, piston, cranksaft, cylinder head (ordered as complete assembly). So here is all new from cranksaft to top.

Last we replaced is carburetor- reason we try also it fix the problem.

Symptom: Scooter start with one kick, so this is good. But it runs about 5 - 10 minutes, and shut down itself. Also it is not possible accelerate- so, when add gas, engine stops. It is same if add gas fast or slow. Maximum speed is a little more than idle speed. ALSO engine make smoke- more than normal, and smoke smell is "not normal".

Next step is replace engine... so all possible is replaced.

* Timing is checked, it is ok.
* Gasoline supply is ok.
* Same fault with new and old carburetor
* Carburator adjusted "three turns"- but no effect is "one turn" or "much turns"
* Also we adjust it carburator needle- there is 5 steps. No effect.
* Piston rings are ok--- cylinder is new, and rings installed carefully.
* Valve clearance is 0,03 mm (we are in Finland...)

I cannot found what I must check next.

[TiberiusDuval]

My first post here, Finnish Kymco owner too.

Your problem is that valve clearance is way too small. It should be 0,08 NOT 0,03. Probably as engine warms up your valves will not shut fully, and engine dies.

[Stig / Major Tom]

My first post here, Finnish Kymco owner too.

Your problem is that valve clearance is way too small. It should be 0,08 NOT 0,03. Probably as engine warms up your valves will not shut fully, and engine dies.

I wondered if he meant .003in. ?
Stig

[Ruffus]

Check once again whether your carb(s) do have  this little washer, spring coil and o-ring within low jetting.
 Valve clearance is 0.12 millimeter both, for starters, then reduce to 0.10 mm.