I just put my new cylinder on last night. Done a leak down test. I had a leak around the back left side base bolt and also around the small bolt in the middle of the base up around the exhaust. I took cylinder and used Suzuki bond on it. Going out to check again now.  But if you don't  want to take your head gasket off to take the cylinder off to use silicone , take the motor mounts off and your swing arm bolt and pull the motor to the side so you can slide the cylinder off. If you have Cool head you can take the jug off  while the motor is still bolted up. Hope this helps you