I have taken the seat off, and the small cover in front of the head but that is all. You should be able to adjust the valves without having to remove the entire large engine cover. Just remember when you put the seat back on, there are 2 screws and 4 10mm bolts. The bolts are different lengths. The long ones go in back and the short ones go up front. It was a HUGE pain to unsnap the front cover to make adjusting the valves easier, just take your time and look at it from behind so you can see how it pops off.