Need Help: The mystery of the exploding muffler

[MidnightSpecial]

Alright so my muffler exploded last night after I got off work. I have some ideas of what happened but I'm hoping someone else ran into this.

-Bought new plug wires and installed them as they were before
-Engine cranked
-Engine was always idling a little strange
-I check the firing sequence and it wasnt right to the OEM 1-8-4-3-6-5-7-2(going clockwise)
-Go to crank the engine over....wont fire.
-Give it a little gas....wont fire.
-Let it sit for a second and turn it over without gas....BOOOOOOM
-My passenger side muffler exploded and busted at the side welds.



It was dark by this time and didnt have time to look everything over.

I can only guess that the timing is way off and once the spark caught there was so much fuel that it just exploded.

I will find TDC today when i get off work and rewire accordingly....no clue whats going on.

[SparkyRnD]

timing is off and raw fuel in the exhaust / muffler. When you cranked, the exhaust valve was open a little during firing, allowing it to ignite and kaboom.

[rohrt]

happens to the best of us. However it is a sign that something is off.