First of all make sure your gasket surfaces are square. We suggest using a known flat surface, glass works well, or anything thet is true and warp free. Lay a sheet of 320 or 280 grit snadpaper on it then take the cylinder head and rub it across the abrasive surface. You'll see immediately if the cylinder head gasket surface is really flat. Work the head around rotatintg it in your hand so you don't sand an angle into it until the surface is uniform.
Do the same to the cylinder. If you don't want to remove the cylinder from the case then stuff a rag into the piston bore so you can capture the material you remove, and use a large flat file with sandpaper wrapped around it to true up the gasket mating surface.
I prefer to do this with the cylinder removed from the case but that's your preference. The studs need to be torqued into the case prior to reassembly. Install two nuts, back to back on the upper threads then torque the studs into the case to 120 to 150 inch pounds. Install the cylinder being careful to get the piston rings aligned with the pins in the ring grooves and into the cylinder. Lubricate the rings with a little oil prior to assembly. Once the cylinder is in place install the cylinder head and install the head nuts. Pick up some new hex nuts, preferably shouldered nuts with a wide flange, and lock washers, torque the nuts to the same as you did the studs, 120 to 150 inch pounds. Throw the acorn nuts in the trash or the scrap parts bin.
You should be good to go using this method. I always suggest using new, unused gaskets but others will tell you the originals will work. Install the spark plug, connect the seconday ignition wire and go ride your bike.
Good luck.
Tom
