Best method of cleaning and freeing up .049

Hope this is the right spot to ask this question about and preferred methods or solvents that can be used to free up vintage Cox .049's. I have some that are gummed up badly or one that's totally seized up. Prior owners must not have payed much mind to storing properly. Mostly the kids who were playing with it last. I probably didn't do much to my own back then so Im guilty also. Thanks for any advice

@Coxoldman wrote:Hope this is the right spot to ask this question about and preferred methods or solvents that can be used to free up vintage Cox .049's. I have some that are gummed up badly or one that's totally seized up. Prior owners must not have payed much mind to storing properly. Mostly the kids who were playing with it last. I probably didn't do much to my own back then so Im guilty also. Thanks for any advice

YES and NO!  
Yes, this is the correct forum!  Cox Engines.
No, it’s not the right “thread”or Topic.   This one is all about the WSTE aka: Worlds Smallest Traveling Engine.  
You could’ve started a new Topic on engine cleaning, but would find your answer much quicker by using the Search box on the upper Left hand side of the page.
This subject is covered by many members, using different techniques usually all with good to excellent results. To quote or mis quote Cribbs Law: “A Clean engine, is a good running engine”.  
Enter and select a topic to follow up on........