Ok Ill try to help you by making a small howto of the kneespin
when you start the spin.. make sure you swing your leg around hard. Because its the only time you will get speed from pushing of the ground
swing your leg (the NOT spinning knee leg) around..
start with your hands and knee far away from the center of your body:
After 1-1.5 rounds of spinning (practice the balance to get 1-1.5 rounds, should be easy)
Start bringing your leg and arms closer to the center of your body.( this is because your spinning point is located just underneath your body)
Don't do it immeadiately cause you will lose balance.. just at a moderate speed. but not TOO slow.
This will give you A LOT of speed, try to maintain your balance by correcting with your upperbody parts.
You should practice a lot maintaining your balance when you get a lot of speed
But youll get it in a short period of time man, no doubt
Try tweaking your kneespin for multiple variations
like:

When you want to speed up in this position make sure you take your bodyparts closer to the spinning point of your kneespin.
I dont really like this variation though, because its a lot harder to speed up
but its up to you
practice
hope this helped you a bit