ms 360 tweaking

[treebender]

I have been enjoying this site for a few weeks; both the good information and the acerbic wit. This is my first post on any board.
My 360 with 20"/3/8" has been a great saw, and handles most of the falling and bucking i encounter as an arborist in middle tennessee. (Poor old 372 stays in the box most days)
For me, saw performance has always been an issue of a clean air filter and carefull bar and chain maintenance. Honestly, I have never turned a carb adjustment screw.
Well, you guys have piqued my interest. Although I do not need to turn my little darling into a rabid beast, i would like to get a bit more. I have been eyeing this side vent epa type muffler, though i haven't tried to open it. I have read some discussion about increasing the exhaust flow for better performance/cooler operation, but have not located any information as to exactly what this entails. I would like to start with the muffler, but sure don't want to get it wrong and hurt my saw.
Any input on advantages (or disadvantages), as well as method would be greatly appreciated.

thanks,
Lance

 

[066 stihl]

Treebender, e-mail me

Ricky

 

[glens]

"acerbic wit"?  What is maple-like wit?

I picked up an older muffler from a dealer with a junk pile.&nbsp; Instead of the sole 3/8" (or is it 5/16"?) hole, it's got a 5/8" hole <i>and</i> a tall, wide, and deep formed vertical slot.&nbsp; I elongated the inner and lower mount holes vertically a tad to better line up the cylinder/muffler interface (not much, maybe 1/16" at most).&nbsp; That was instead of working on the rolled edge of the muffler inlet.

Funny thing happened though.&nbsp; It seems to have made the ears of the screw-stops fall off the carb adjusters.&nbsp; Now if I'm not careful to leave a screwdriver out of them they'll go 'round and 'round.

It's a good saw.

Glen

 

[Crofter]

Treebender, do a search on "muffler modification" here and you will get lots of ideas. Just remember that if you open the exhaust it will be necessary to readjust the carb as Glen hinted at ( he is so subtle). Make sure you don't have the high speed jet on the TOO LEAN side or you risk ruining your saw. There is a sound file on the Madsens site on what a properly adjusted saw should sound like. You should be using hearing protection anyway, but after you open the exhaust it is absolutely a must for you and anyone else close. My bush pilot (wife) is not overly impressed with the new voice of authority from the saws. You will see in the neighbourhood of 20% measurable reduction in cutting times.

Frank

 

[treebender]

thanks fellas.

Acerbic wit, Glen? it is a (verticillium) wilting strain of humor that sends big egos into decline.

I removed the muffler cover , and to my suprise, it is empty! I expected to find something on the order of a catalytic converter.
The mating of the muffler to the cylinder outlet was very close and even, the muffler being about 1/32" narrower on the sides and even on the top/bottom. Is this worth expanding?

Glen, in your description of the the junk pile muffler

"it's got a 5/8" hole and a tall, wide, and deep formed vertical slot"

I assume you are referring to the exhaust port. The exhaust port on the side of my muffler is about 5/8" in diameter, with room in front of the screen to expand it greatly, or add another hole. I am thinking about removing the screen,drilling another 1/2" hole, and replacing the screen. Would this be adequate?

As far as adjusting the carb, the madsen's site was informative on that and many other topics. I intend to try to buy a lesson from someone local. Madsens advises against removing the screw stops as there are no longer springs to hold the screw in adjustments. perhaps i should remove the stops, wait for the "ears to fall off"(wink wink, nudge nudge, say no more) and reinstall the stops?

hope you had as good a july 4 weekend as i did.

lance

 

[glens]

If you've got an MS360 and not an 036, and nobody has modified the muffler, then there's no way you have a 5/8" outlet hole.&nbsp; The older one I found had a hole that size and in front of it the slot I described.&nbsp; I can't venture a guess as to the cumulative area but it's vastly greater and the noise isn't obnoxious.&nbsp; If I couldn't find one like it, then I'd modify the new one in some fashion.

Glen

 

[glens]

Hi Brian.

Don't know if you've seen the inside of an 036/360 muffler, but the lip that would get filed is a layer that's rolled 90&deg; towards the innards of the muffler for about 1/16".&nbsp; A fair bit of filing would be necesary and it would leave it too thin, really requiring total removal.&nbsp; Maybe that would be okay, but the strength of the configuration is certainly worth the tiniest (smooth) obstruction likely present.

Glen

 

[treebender]

Glen, your right, nowhere near 5/8". I got a couple of measurements confused.
Your description of the rolled edge is dead on. I will leave this alone. I plan to look for an older style muffler, wonder what you would get if you ordered a new muffler for and older 036.