I am working on getting a 2004 ET4 with 4500 miles on it. It was given to a friend so helping get it running. So far:
Drained varnish out of gas tank
Replaced fuel tap
Replaced rubber lines
Cleaned carb but corrosion in bowl so ordered new one
New plug
It will start but runs erratically and idle screw does nothing but proves engine can run.
While waiting for new carb continued with other tasks such as cleaning old grease out of front hub and replacing brake fluid.
Brake fluid was interesting in that, I believe it is the original brake fluid so like 20 years old. Caliper not frozen as I was able to push pads back with screwdriver. Took pads out and sanded rust off. Here's some pics I thought would be interesting to share.
Not looking for any advice yet on this scooter as more to do

