normally, if the carb is leaking out of the overflow tube, that means that the float is set too high.
OR, there could be something in the needle & seat causing it not to close all the way.
the needle & seat is the little valve that opens whrn the float drops and closes when the float is raised.
all it would take is a TINY peice of debris to get in there, and it would cause the carb to flood over.
A lot of times with these carbs (n.t. carbs anyway) the float will get cocked sideways and wedged so that it won't close the needle & seat all the way.
But since you say that you had it apart already this is probably not the case.
another thing is what angle is your engine at?
if the engine is not level, the carb won't be level, and it will flood over and leak out of the overflow tube.
**I just went and looked at the pics of your bike and engine***.
It looks like your engine is at too much of an angle...you need to raise the front of the engine, and lower the rear of the engine to get the carb level. It looks like the carb is at too much of a forward angle, which could be causing it to leak out of the overflow tube.
As for the chain coming off....Is your chain alignment right?
if your chain is running at a slight angle, it will come off.
Look at the bike from the rear, and eyeball the chain from rear to front.
Make sure it's in a straight line.
If it isn't you'll have to figure out how to make it run in a straight line.
You could also have had a bad link, or a stiff link in the chain.
these chains aren't the bst quality, and if you don't go through the chain link by link to check them for being tight, it might break.
did you libe the chain once you put it on?
the lube that comes on these chains is only to keep rust from forming on them while they sit in the box. you should lube the chain with a spray lube, or grease...NOT wd-40. WD-40 is not really a lubricant.
