I have a 1987 cbr 600r Hurricane and i need to know how much air to put in the front forks?

The front forks are adjustable to the type of ride you want. First, set the rear shock to the setting you want soft, medium, or hard. There should be max pressure information in your owners manual and on a sticker on the front forks. Typically the most pressure that can usually be put into a Honda front fork is around 14 PSI. Add, carefully, 10-12 PSI using a hand or foot bicycle pump with a gauge on it. You will probably find this way too stiff. Be careful not to put too much pressure in the forks or you will pop the seals and have to replace them.Then with the bike loaded the way you are going to ride (soft for comfort or hard for two up riding) bounce on the seat. What you want to feel is the front and back suspension dropping at the same time. This is how racers set up there motorcycles for hard cornering. If both the front and rear of the cycle drop together you have an easier time controlling the bike during extreme maneuvers. Since the front is usually stiffer than the back(you added pressure there) slowly bleed the pressure out of the front fork tubes until the the front and back drop together while you are bouncing with the bike loaded the way you are going to ride. Now you are set up for extreme riding conditions. Soft or hard that is how you set up all motorcycle suspensions by balancing the the amount of front cushion/pressure to match the back cushion/pressure.