Carefully flip the covers off them so you can see the grease on the balls. Now wash this grease off with gasoline using a small paintbrush. When all the grease is gone, re-grease them with new grease and put the covers back on.
simply with a toothbrush, and you don't need to clean it to often.
For a kids push scooter, there are 2 bearings per wheel, 2 wheels per scooter. 4 bearings total. If you buy a pack of 8 for a skateboard, you will have 2 sets.
depends on if there clean oiled and not rusty if theyr new usually 30 secs
it is an Australian type of bearing and is equivalent to abec9 bearings.
abec 7
ABEC 7s
yes
Yes, most bearings are the industrial standard of 8mm unless you have special longboard trucks, most notably Bear 1052's or 1045's or Bear Smokeys, these trucks run 10mm but are not very common. If you can take wheels off with the same wrench on both trucks, then they have the same size bearings.
No Because It will damage your scooters back wheel it is also known to loosen bearings too
bones, bones, bones, bones, abec
yeh
Bearings in a scooter are a great idea. A scooter without bearings will work. For a short time. Then the point where the stationary (none turning) part touches the turning part will begin to got hot from friction and bind or will wear away so round parts will be flattened. Then the scooter will stop working well. Then the scooter will stop working at all. Lubrication the area will make it last longer but the result will only be delayed. Properly designed and installed bearings between rotating and non-rotating parts are amazing things. They will roll between and with both parts reducing friction and wear so much that it can last years longer.