I'm putting my stock exhaust back on, loud rattling coming from one of the boomtubes. I pulled them from my shed, found some crap inside them from critters over the years. I've cleared out just about everything. Will it hurt anything if I put them on and blow out the rest? Or will it be sucked back into the exhaust manifold?

 

There is no suction on the muffler side of the engine unless your valves are shot....and then you would have a bad miss. You will have no issue there.

I would worry more about what is left in there building up in a bunch and blocking the exit and restricting the exhaust flow. Can you use a shop vac and suck more crap out....

 

Thanks, I've been using an air compressor and have blowing out parts of leaves and other crap, probably from mice. It's to the point where I have a solid flow of air from both ends of the exhaust. Just want to make sure that whatever is left inside there, will not ignite.

 

You very well could have dead mice in there too and whatever is in there will get roasted. Only way to tell is to fire it up and cook em!