Hello, I have an older 1979 RM 250 motorcycle. The engine is in great shape, and everything works OK (Except for the shocks, but that's a whole nother thread). I was wondering how I tell if it has a spark arrestor on it? If it isn't a spark arrestor, is there any way I could put a screen in the muffler (Weld it in or otherwise, i doubt there are aftermarket mufflers still available, and even then, I don't have the money!)There's a gap where the muffler fits into the pipe where I could easily wedge in a screen, it would work great, but would I get a ticket or some crap for doing this? The muffler right now is straight- through with a baffle all around the diameter of the pipe. Any spark arrestor mods out there?I would be willing to cut the thing in half, weld a grate into it, then weld it back together, would this suffice?