Your guides are not iron and sticking is not a "usual" problem. It is possible to get a piece of carbon stuck under the intake or compression valve or decompresser valve. Maladjusted valves are the number one cause of this malady. If you are sure about the valves and the decompresser valve (they do stick and/or burn once in a while). if you can't figure this out a crude but effective way to get a better handle on it is to braze an airfitting on an old spark-plug that you have gutted. Bring the piton to TDC on the compression stroke and put the air to it. You do not need much pressure. You can then listen to where the air is coming from.
Thanks for the feed back. You guys were absolutely correct I pulled the head off and there was a small chunk of carbon stuck on the valve seat! Didn't take much to make it leak I'm now waiting for gaskets. I couldn't believe how wonderfully easy it was to pull the head. I truly love this thing!