It has 6 gears.
It's a 5 speed
about125mph
6 . one down 5 up
with your hands
Because it needs more gears to get up to speed because it doesn't have good acceleration.
yz
The other person that anwsered didnt know crap about a yz 80. all 80 have 6 gears It one gear down to get into first and then 5 gears up to make it a 6 speed. I have a yz 80 so I know unlike the other guy.
this should help you. http://tinyurl.com/msksw5
I topped out my yz 450 at 110mph. with just a few modifications
You need the mixture of gas and oil mixture for 2004 YZ 125 in the ratio 1:32.
a yz what engine size? Probably about 2-4 seconds IF you can hang on AND keep it on the ground long enough to shift gears.