Resonator blew apart

[rowdy jag]

I just replaced my fuel filters and started ski up - running ok but a little rough - just thought it needed to run a bit to adjust from the maintenance. Shortly there was a loud backfire and upon inspection discovered the resonator blew apart.

What would cause this?

Thanks for any assistance.

 

[Digdog]

Bad plugs or coils or the connections to them.

 

[rowdy jag]

OK - I will change the plugs out, go from there and hope for the best....Thanks