Engine Trouble Engine doesn't idle.

[dmpatanis]

Hello,i have my motorized 66cc bicycle for 4months now and today i have a problem.When i release the throtle the engines goes to die.It doesn't idle.
Why???
I have the 66cc chinese engine with standard carb.I screw the idle screw that the carb has but nothing happens.The engine dies.Why???
What i must check??
Thanks a lot.

 

[happycheapskate]

Start with your fuel tank and fuel filter. Is there fuel (seriously). Is the little filter on the brass part with the hose barb plugged up? (this happens a lot. Most people take the little red filter off and use an in-line filter from a mower store or auto parts)
Next, check the air filter. Have you cleaned it before? If not, clean it regularly. The foam ones, wash with soap and water and air dry. The paper ones, just replace with the correct one. Now pull the spark plug (cold engine). Is it oily, or ashy? See the other threads about spark plugs and engine/carb tuning. If it looks normal, put it back or replace with a similar one since you already have it out and they are about $2.

Do all these things even if one is the obvious problem. That should help you a lot. If not, you may have a plugged up carburetor (metal flakes, water, or rusty stuff in the bowl is usually what happens)

 

[dmpatanis]

I clean the magneto in the engine with petrol and now i havent got a spark.
Why????What to do????
Thanks a lot.

 

[BoltsMissing]

I clean the magneto in the engine with petrol and now i havent got a spark

Plenty of links in the ads here, get a new "magneto" and don't wash it in petrol again, no need to wash that particular component at all ! The petrol probably erased all the coating off the fine copper wire winding, therefore shorting it out.

In future, just make sure it's dry and handle with care cos it's flimsily made in....

Get the cover gasket while ya at it, when you put the cover back on, use sealant around the gasket and cover so no moisture gets in.
It's been known these "magnetos" can short out with a slight amount of condensation. So when you get your new "magneto", make sure the hole in the casing where the wires come out from is sealed up to.

I think the correct name of the part is "magneto coil"
item Z55 on this picture list

http://www.zbox.com.au/spares.htm

 

[dmpatanis]

Hello,i made all the upper and no responce.
I clean the air filter,i change the fuel hoses and the idle is very low and the engine stops.
I use a 50:1 oil mix ratio in the tunk does it matter???

 

[dmpatanis]

I remove the carb and the copper big screw it was uncrew all of them.
Here is the problem

 

[joeltrain]

My Experience

I see you solved the problem. I wanted to add for others experiencing no idle that for me idling problems were always solved by using a leaner jet. I noticed that the higher size jet is use, the lower the idle. I currently am using a .66 and its **** near perfect. Just a little rich but idles nicely. i found a nice easy to understand reference guide to jetting here: http://kenoconnorracing.com/Carburetor jetting.html . This refers to motorcycle 2 stroke tuning but the basic mechanics of it are the same.