hey i got the yyf one and am using the string that came with it but the string wont stay on my finger any help will be greatly appreciated thank you 
did you try a slip knot? … or you can just cut the loop and tie another one and try again.
This should explain it.
Assuming you understand the whole slip knot thing…which is the standard deal for yoyo…
The yoyo factory string does the same thing to me I hate that stuff…it loosens up from your finger right??? Slips around???
If the is the case after you make your slipknot twist the overhand(the one tied on the end of the string) about 4-5 times and that will keep it from backing off easily.
Make sure the loop in the slip knot faces to the right if you’re throwing with your right hand.
yes that is exactly what happens what do u mean twist it ? thank you ;D
When you put the loop through the end of the string making the adjustable slip knot, twist the loop around that is always tied in the string this will lock the slip knot down the more twists the less slip…to many twists it won’t come off :
thank you!!! ;D ;D ;D 
;D ;D