Motorcycle Repair: ATC 90, rear sprocket, valve clearances

Question
Just recently purchased another ATC 90 to add to my collection of ATC's but it has me a bit stumped on how to disassemble the rear sprocket, hub, break shoe assembly i have the axle out but then what?.
The other issue i have is it will only start and run with choke on soon as you take the choke off while the motor is running it dies (this is with no air filter off)
Be great if i could source parts as, well getting pretty hard to find parts over here in New Zealand

Answer
Richard..

Servicing your ATC90 requires the BIG WRENCH to remove the BIG NUT on the axle.
http://www.cmsnl.com/honda-atc90-k3-usa_model52/partslist/F++10.html  #17
Note that drum is splined onto the axle, so you may have difficulties in removal, if it is badly rusted.

http://www.atvworks.com/products.asp?cat=64  

http://www.atcheaven.com/index.htm

for wrench example. Then buy a suitable 5 lb sledge hammer to use to get the wrench to loosen the nuts. It is a good job for a blacksmith.

Always check the valve clearances on hard to start/won't idle engine conditions first. Once that is completed, check compression to see if it is in the 125psi range. If compression is good, check ignition timing, so points open at the F mark timing alignment with a maximum .014" gap set first.
Finally, remove carburetor and clean out the idle jet, main jet, main jet holder and any leftover muck in the bottom of the float bowl. A full overhaul and cleaning is best for most carburetors.

There are many ATC-ATV parts dealers in the US, most of whom will ship internationally. Some engine repair parts may still be in Honda's parts system, but a lot of it is discontinued, so you will have to use Ebay or similar sources to locate a lot of it.

Bill Silver