I have 2 TAOTAO 110cc atvs for my children. One of them starts and runs great even in cold weather. The other takes forever to start if it starts at all. Here is a list of what I have done:

Replaced starter (fried the first one tring to start it)
Cleaned the carburetor in case there was a gel pack
Replaced the oil (I did run it before I found out how bad the oil was, it was like paste when it was coled).
Swapped CDI modules
Swapped spark plugs, Checked gap
Adjusted the carburetor according the guide in this forum (Many thanks to the author)
Check compression
Checked safety and kill switches, no effect on starting.

Current Symptons: Somethimes it will spit back through the carburetor, other times it will not.
Occasionly produces loud pop from the exhaust.
When it does finally start to catch (almost to the point of frying the starter), it will start after another 15 min. of trying. If it starts, it runs great until the engine cools down. Then I am back at square one.

I think the timing is somehow slipping, but I do not know how to check or adjust the timing on these things. Any suggestions would be very helpful.

 

Right after I posted, I went out to try and start it again. It started and ran in under 2 min. I am still convinced something is wrong though.

 

There is no timing to worry about.
The stator has a fixed point pickup that is not adjustable.
Its probably still the carb
Often times cleaning is not enough. You need to get a pin or piece of wire through the small hole in the main jet.
If the jets are not fully clean it will forever run like crap.

 

Thanks bill. I will take another stab at cleaning the carburetor this weekend.