Hmmm. Where are you located?
You should do a leak down test. I'd say you developed an air leak. Try to avoid a dealer. There's a few things you can do to keep the engine from blowing. Good mix, good fuel, good jetting. You can do a leak down every few months if you want and a compression test. That's about it. After that, shit happens. Use quality parts to do the rebuild.
It may be cheaper for you to buy a complete engine and get it shipped tho depending on where you are.