Why do only have three gears

[Jason82]

I just got a rebuilt bottom end and got a brand new top end and when it started i only have three gears

 

[jimmu]

Time to take it apart and double check everything, especially your shift forks. It's a good practice to run through the gears after assembling the bottom end.
https://www.youtube.com/watch?v=wE57TzQ0cbghttps://www.youtube.com/watch?v=wE57TzQ0cbg
Check out Ken O'Connor Racing's videos on YouTube.

 

[Larry's Shee]

Is this while riding, or engine off, sitting still? Is there any oil in trans? How poopy is it?

Also check external shift mech. under clutch cover. Worn parts, lose shift starhanging clutch.