Hey, sorry it took so long to get back about this.
Well, Husqvarna was NO help. They immediately blamed the incident on faulty maintenance. In other words, it was my fault.
They said the only way that could happen would be a loose chain.
Well, I know that I had just tightened the chain before the problem occurred.
The dealer was less than helpful. They acted like I was just causing trouble. I've spent a lot of money at that place over the years. No more.
So, I stopped at the auto parts shop and got a plastic tank repair kit, (thanks to all that suggested that). It sealed the tank up fine.
I left the chain and bar off the machine and fired it up. The engine ran fine. I did notice one thing. The anti-vibration suspension works really good. The motor and all the working parts vibrate like mad, but you don't feel it at the handle.
So, maybe the chain did come loose, because the vibration is SO BAD! I don't remember the nuts being loose, but I was more concerned with the gas squirting out at the time.
Anyway, I put the chain back on and added lock washers under the chain bar nuts. The machine works fine, but I did check the nuts every 20 seconds for the first ten minutes.
Today, I was cutting up a large red oak. Ran fine for the first 2 tanks of gas. On the 3rd tank, sure enough, one of the nuts backed out, even with the lock washer.
Guess I'll just have to keep monitoring the nuts.