MS-362 Muffler Mod - pics and info

[GM-GUY]

Well, I did it, my saw is out of warranty (by a week) - so I took the dremel to it. First, you only need a Tungsten Carbide bit (9903) no pic, I tried a different cutter at first - complete waste, one of these will do just fine.

The first pic is of the un-moded muffler with grease over the screw hole (so I didn't hit it with the tool). I also greased the whole screen and put it back in to keep the dust out of the cylinder as will as cranking the piston to the top for additional safety.

The second is the pile of shavings removed.

The third is of the opened muffler, pre clean up.

I then pulled the plug (fourth pic) - looks good I believe not burned or wet. Used an air compressor to blow air through the plug hole with the piston lowered to open the exhaust port.

The fifth pic is the result and done.

The sixth is the thin strip of rubber I use to block the H screw after removing the plastic limiter. I just jam it down the hole and against the screw to keep it from vibrating around. I have read their is no more spring to hold it in place.

The seventh and last is the Tech Tac max RPM. It shows 13161, I can't get the last two pics to load - I'll have to mess with it later.


NOTES:
I needed CCW +1/8 of a turn from where I was on this mod, I started at +1/4. The idle has to be at 3000, not the stated 2800 in the book - it tends to die too easy at the lower number. My Tech Tac is dropping the reading at WOT when left running for 2 seconds - it drops to a ?50% reading? - If you slowly increase the throttle you get a 'good' reading.

Anything scary that I have done? I'd be interested in what others have for readings when doing this mod. The saw has more 'throat' to it now - it sounds more like a saw - I'll be cutting this week. with it.

I used these instructions for setting the RPM Chainsawr Adjustment and Tuning of a Chainsaw Carburetor



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[blsnelling]

Please, please, please remove the muffler before attempting a muffler mod The limiter cap should have gone back on after removing the limiting tab. Your tach reading is misleading because you're hitting the rev limiter, making it read low. Anything other than WOT means nothing as well. Please read up on tuning in the wood. Also, it if won't idle below 3,000 RPMs, that indicates that your tune is off on the L needle.

 

[Deets066]

Why not remove the muffler and do it right, remove any baffles inside and match-port your muffler to exhaust port on cylinder. Just a suggestion but I'm sure this mod made some improvement.

 

[GM-GUY]

I thought about pulling the muffler, but realized the 362 doesn't have the baffles like a 361 does, just the outlet hole was tiny. I did read about that - the 80% rule, but didn't want to get too crazy.

The wood test is next - Tuesday I think.

I would love to put the H cap back in. but I broke and lost it last year.

 

[GM-GUY]

I think I'm really good now.

First I ran the saw and messed with the idle - I got it down some, I may play with it more but I've got excellent throttle response and no stalling - I'll see how it does in the summer I think.

Next I went way rich until it burbled and brought it back - "As close to smooth as possible but just into the rough" I read somewhere. Tach said 12K+ steady at WOT.

I hit the wood, 16" bar in a 20" pine, it' didn't cut great - good, not great, I tach'd it at ~8K in the wood. Max power (per the book) is 9,500RPM. I leaned the saw to 13K- steady at WOT now I hit 9,500 +/-500 in the wood. The saw cuts like it should also - plenty of power and very little heat.

Max RPM per the book is 14K so I'm happily rich - the current top RPM is also coincidently where I ran the saw last year - just richer on the H due to the muffler mod.

 

[Adirondackstihl]

I thought about pulling the muffler, but realized the 362 doesn't have the baffles like a 361 does, just the outlet hole was tiny. I did read about that - the 80% rule, but didn't want to get too crazy.

The wood test is next - Tuesday I think.

I would love to put the H cap back in. but I broke and lost it last year.

The point of pulling the exhaust is to keep the shavings from entering your cylinder and so one can remove the shavings from the inside of the muffler when done.........
Your effort to keep shavings from the tapped hole was........well......meaningless at this point

:bang:

 

[brokenbudget]

seriously?
is this guy joking?
leave the muffler on while grinding?
gooooood luck.

 

[cedarshark]

I hope this "on saw" muffler mod works out well for the OP...but I would be very nervous:dunno:

 

[brokenbudget]

I hope this "on saw" muffler mod works out well for the OP...but I would be very nervous:dunno:

oh don't worry. he used compressed air through the plug hole to blow them chips right out.
everybody knows when you blow compressed air into anything it totaly carries all the debris right out the exit and not back at you from where ever you have that nozzle pointed

 

[blsnelling]

Hopefully it blew out the metal chips and not the crank seals:msp_ohmy:

 

[brokenbudget]

Hopefully it blew out the metal chips and not the crank seals:msp_ohmy:

chips and shavings would seal them back up.

 

[Adirondackstihl]

Used an air compressor to blow air through the plug hole with the piston lowered to open the exhaust port.

Yup....and ya blew all those chips into the cylinder, down the transfers and on into the base.
But don't worry, the muffler is clear.

I think this little modification is gonna cost you some bucks in the near future. If you don't know how already, you should really learn how to change the bearings and seals on a 362......real quik like.

I'd be scared to even pull the starter rope let alone run it.

 

[cedarshark]

Yup....and ya blew all those chips into the cylinder, down the transfers and on into the base.
But don't worry, the muffler is clear.

I think this little modification is gonna cost you some bucks in the near future. If you don't know how already, you should really learn how to change the bearings and seals on a 362......real quik like.

I'd be scared to even pull the starter rope let alone run it.

We all have to learn, and I hate to pop the OP's bubble as he was proud of his mod. Sounds like the saw has been run since the mod, probably has chips and shavings below the piston and in the crankcase. To avoid a catastrophic failure, I would suggest you not run the saw, plan on removing the cyl, piston and washing all exposed parts. Not sure how you will get the bearings clean but I would start with hot soapy water and plan on multiple rinses. Not sure you could even get them all that way. Sorry...cuz it's a next to new saw.

 

[GM-GUY]

You guys missed the part where I greased the the screen (fully covered) and the screw hole was covered also - I didn't want to ding the screw so it wouldn't be able to be removed. I also minimally opened the exhaust port when I put the compressor to the plug hole.

Then when I got some grease to blow off the screen and out of the screw hole I pulled the screen and cleaned the grease off.

I have indeed run the saw since and its fine. If it wasn't windy today I would have taken down another tree, as it was it was just cleanup work and brush pile stacking.


I looked at this similar to an EGT mod I did on my diesel pickup (pre-turbo) - used grease on drill & tap and let the engine idle. In this case I didn't idle as I could block the screen.

 

[Adirondackstihl]

:msp_confused:

 

[brokenbudget]

nobody missed it. all this shows is how you do things.
thanks gawd you're not my "mechanic".

 

[qbilder]

The time & work you put into the grease method, you could have just easily have pulled the muff & done the mod on your bench, with no threat of getting debris into the motor. You would only have a few bolts to remove. No grease to clean up, either. Any particular reason you prefer that method?

 

[GM-GUY]

I pulled the muffler off my old 036 and had all kinds of gunk and crusty nasties break loose - I didn't want to make that kind of mess that close to the cylinder. From what I read last year, I was under the impression pulling that muffler was a pain.

Noted for future reference - pull the muffler.

I'm done fiddling with the saw anyway - this was the only thing on my 'to do list'. If I get into bigger stuff on a more regular basis, I may have Stumpy or Mastermind work their magic - but can't really see that as needed. The saw has better power and runs cooler than it did - comparing how it cut before and after the mod.

I also checked the screen before I posted this and no metal flakes noted.

Now I get to watch the rain - I don't cut in the rain, the saw might get rusty :hmm3grin2orange:

 

[cedarshark]

If you were lucky(and I hope you were), listen carefully for a bearing starting to growl. If you don't catch it early, the cages will come apart,& pieces get thrown between the piston and cylinder wall. It will make you cry:cry3:

 

[KenJax Tree]

:msp_scared: