engine will not fire

S, you can tighten the clutch spring by removing the clutch cable stand-off on top of the back of the engine casing.
Stick a screwdriver down in there to engage the nut on the drive shaft that holds the clutch assembly.
With the screw driver holding the nut, turn the clutch, or sprocket, to tighten it a turn or so, then try your clutch action and effectiveness again. Repeat if needed.
Good luck
rc

Also make sure the clutch gear has a key in it. Although from the sound of it I'd be pretty sure a key is in place...but check. These engines have been known that a key has not been installed from the factory.

shaver said:

Do I rotate the sprocket clockwise or counter clockwise? I have played with the tension on the clutch housing (removed the little screw and changed the tension) and got it a little better, but still not right. The clutch housing (that holds the clutch pads?) turns fine, it;s just not engaging the large sprocket which in turn turns the smaller sprocket tied to the piston. It just turns occassionaly and not consistantly. I'm sorry to be so questioning, but eventually I think I'm going to be riding. I hope.

Click to expand...

Rotate the nut on the crankshaft clockwise so it won't loosen up. When you turn the crankshaft (where the magnet is) it turns the small gear on the clutch side. This now turns the large (clutch) gear, when the clutch is engaged (flywheel pulled inward) turns the drive sprocket that turns the chain. If any one won't turn or only occasionally I'd look at the woodruff keys.

Alf, I got an idea here...

Shaver, it seems to me like you are having quite a bit of entertainment from this little project, which is possibly half the reason most of us are here...

May I suggest you read through all the related posts from Lord Vader and Alf, then dis-assemble the entire drive unit from your chinagirl motor?

Have some solvent handy, and a bunch of grease rags to discard...
(I'm a real cheapskate, and wipe off the big stuff using old newspaper to discard, before using the rags, which are now harder to come by since I no longer work as a painter.) yah, I got flammable trash cans!

After complete dis-assembly, from clutch to sprocket, you will understand the mechanism of how it works. It is quite ingenious! and very simple.

...the flower nut's purpose is to control dis-engagement of the clutch...

Best
rc

Yes very simple design. Here is what you will be looking at. The assembly can be removed without splitting the case.

Well good!

We're all glad you triumphed over the obstacle in your path to fun!

And thanks for the report!

Will you post some pics when you go out on some adventures with your new motorized bicycle?
We like pics!

Best
rc