Suzuki Bike Cover My Bikes Spark Plug Keeps Popping Out Whats Wrong?

My bikes Spark plug keeps popping out whats wrong? - suzuki bike cover

I have a model 1972 Suzuki 90th Whenever I try to start the spark plug popp motorcycle. Coverage, but remains in play with what they are called spirals popp up. Any tips? Please, no jokes that I sell the bike MX-start race.