Changing head gasket
Hi Go, I NEVER pull an engine on NE5 for head gasket, and infact recently rebuilt (exchanged out entire top ends, converting to NE from WC1) 2 nice Whizzers in frame, and actually, since it wa a nice day both times, right out in the front yard enjoying the summer air!
Tricks? Hmmm I dunno, I remove the tank, set aside (notice I did not say Drain the tank?), then I use LONG (like 6" or so) Ball-end Metric allens to do the work, using a 3/8 inch pound torque wrench.
I ALWAYS lap the head. What, you are not a "Lapper"? Well you oughta be!
Extremely flat surface new sheet wet or dry sandpaper, used wet. You can use 240-400 depending on how much warp you may have. Lay head on the paper FLAT rotate in circles, continue to read the head untill a nice sanded finish appears evenly on the mating surface.
Rinse well, dry with paper towels (wives will usually scream if they catch you with cylinder head nd thier kitchen towels!
Reinstall, torque down in the usual way. Reinstall tank, Ride Well!
Mike