To check your timing mark you need to see where your timing mark is with the piston at top dead center. Should be at zero. Probably should use a piston stop but to ball park it look down the sparkplug hole or use a plastic straw off a spray can to feel tdc while a helper turns the motor over by hand. Not with the starter. Be careful, don't drop the straw down in the hole. It will be easier to turn the motor with all the plugs out.