Bike wont shift

[zarak]

my 1980 suzuki wont shift out of 2nd or neutral. i can push the lever all the way down or up and it doesnt shift. i had took off my clutch cover. when i did that i had the bike on its side and never changed the oil. would that have done anything? or do you think its something else?
thanks

 

[Dylan19302]

Sounds like something is jamming up in your shifting mechanism. get a manual and inspect it with the pics in the manual