How do you check the oil level on a 1978 Honda Goldwing gl1000?

There is no dip stick on these models. So, with the bike on the center stand, start the engine, look down around the foot brake area, you will see a little window with a screw in the center, that's the place. Use a flashlite and have someone turn off the engine, you will see the oil settle. The level must be in between the lines.