Having issues with my motorcycle. Please assist me?

When i start my motorcycle white smoke comes from the engine. When i ran it for a bit to see if it would clear up, it did not. I loosened the radiator cap to check the levels after i ran it and a lot coolant came gushing out. The heat seems to build up quite quickly on the bike. And not a master mechanic but i know a few basic things. I would appreciate if you could tell me what you think it is, and what sort of action i should take. Thank you for all your assistance.
Added (1). also it is a 1986 Honda Magna VF700C with 71,000 miles on it

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