So I have a couple of these kicking around the shop now and one has a nice big dent in the side of it. I decided it would be the perfect victim to sacrifice in the name of science. Opening this thing up has given me a ton of insight as to what's inside these and why the 361's Achilles Heel is it's muffler. Back Cover -- The outlet on these actually points backwards towards the operator, relying on the deflector to turn the exhaust around towards the front of the saw. And here's the front half. Big birdcage type baffle that empties into the can. Exhaust in the can then has to find it's way out through that pipe. Extremely restrictive. Also note that the pipe and baffle assembly is spot welded pretty securely to the front half of the can. So don't get any bright ideas about twisting it up and yanking it out of there without splitting the muffler. I now have a pretty good idea now of what I want to do muffler-wise for my upcoming 361 project.
At least this thing looks like an engineer thought it up. The 1127 (290/310/390) series mufflers are just "special". Two outlets the size of a tic-tac for a 65cc saw.
I had a thought.... I checked out pics of aftermarket mufflers on eBay and I found one or two that look like they do not have the internal "birdcage". Can anybody confirm for me that such a critter does indeed exist?7
Wow... The two MS 361 ' s that passed through my hands were not impressive in my opinion.. Because of the need to split the muffler, they were the only 2 saws I probably never messed with. This thread shows exactly why.. If all that garbage was removed, or another port in the side of the muffler was added? They would have ran MUCH better. MasterMech, Are you gonna post up pics of the muff mod you intend on fabricating?
So it looks like another port could be added just about anywhere, avoiding the need to split the muffler... Or is the cage too restrictive? Maybe just drill out part of the cage through the inlet? I agree with Dex... I had two different ms361's and I thought they were complete turds. I wish I would've tried a muffler mod on one of those saws before I got rid of them.
Yup, a port anywhere on the can will improve flow. The bird cage ain't all that bad, lots of surface area and lots of holes in it. Plus it will do a lot to keep noise to a reasonable level.
I've seen dozens of those saws with a bunch of hours on them that the cage had come loose and was rattling around in the muffler. I've even seen em run so long like that, that the cage was beating holes in the front of the muffler.
This one is spot welded in there pretty secure. But I'm pretty sure this was a very low hour saw that met an untimely demise under a truck tire. If the cage would pull loose pretty easy I could get it outta there without too much drama.
Oh, that one's a goner. It's got a crushed corner, although it's usable if someone wanted it. The real fun begins when I dig into the pile 'o parts labeled "361" that's currently in a box under my bench. Just got the gasket kit in, now get it broke down for cleaning.....
Upper left corner of the front half is pushed in a bit. Can't really see it in the pics. Still perfectly functional tho. Maybe I'll gut it and weld it up just to see...
Funny you brought that up today... I was cleaning/reorganizing the garage today and found a 361 I forgot I had (along with lots of other stuff, ). bought it from a dealer.. saw was new, less than 10 tanks thru it and it fell off the back of a truck and someone ran it over... the case and handlebar took the damage...first thing I did when I got it and tore it down to find a mint P/C, then proceeded to gut the muffler.. this was years ago and I forgot I had it until today....got an extra case ya wanna sell? I remember Dave Nieger had one heckuva 361 I ran years ago.... These mufflers remind me a lot of the Dolmar 5100/7900 designs, except those you can split easy. Most guys don't weld, and idk if I'd trust braze to hold the whole two halves together under serious R"s and vibration over time. I know mine got welded back up...
