More than likely you've simply fixed the compression leak and now it's as it should be but to ease your mind I agree with what spaceworm said. Take the plug out and see how it feels. I'm presuming it's a pull start car engine and these can feel hard to spin over because of the very small leverage acting directly on the crankpin. It's not a pinch problem because you can spin it over easily when there's a compression leak. One trick some people do is to loosen the plug just a little to give a small compression leak then, once it's running, tighten the plug but I don't really recommend this.

And sorry Dar, but that bit about an extra plug washer and reducing outward expansion of the sleeve because of less compression......well, what can I say ?