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
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.
You need the mixture of gas and oil mixture for 2004 YZ 125 in the ratio 1:32.