Clutch seel!!! sorry its the seel on the clutch cap that you screw on to the clutch it has five screws. Well I would try some siliclone but it might not work. Did you say that the fluid leeks out of where the cable meats the decompressor??
does it leek when it is not running??
If it is leeking out of where the cable meets the decompressor i don't know what to tell you other than get a new cable. Hope this helps:
If all comes to worse send me the motor and I'll fix it for you.
You should sook in to a 70cc kit and a smaller rear sprocket it is way more fun.
Mopedwarehouse.com is the place.