honda izy not hard to start?

hello ,i,ve got a honda izy hrg 465 c2 which is very hard to start .So far ive replaced the plug ,air filter new petrol then compleatly stripped and cleaned carburetor , hole in filler cap aswell but im still having a hard time getting it to start .Im out of ideas now has any body had any simalar problems and fixed it ? When it does start it runs ok