MS 361 improvements

[SamT1]

So I have a 361 that's not going to cut it stock. I’m in it cheap so I’m gonna do some mods and try again.
How much would you advance the timing?
I’m going to delete the base gasket.
Slightly widen the exhaust port.
Raise the exhaust atleast the width of the gasket and any I take off the base.
Do the muffler.
I’ll clean up any imperfections in the intake. But I don’t really have equipment to port the stihl transfers any.

What else do I do to the thing?

 

[SamT1]

I also saw where you can bolt in a 460 Oiler. I run short bars but could go for any improvements in bar life as long as I can still run a full tank of gas to a tank of oil.

 

[Rick Stephens]

 

[Rick Stephens]

Gots to measure squish before you know what a base gasket delete is going to do. Personally, I haven't found a delete does much unless you also work on port timing to correct for lowering the cylinder - which leads to opening up the ports, which is more beneficial. Just the MM will do more than base gasket by a bunch. Don't forget to retune the carb as it will usually lean the saw out a bit when you open the muffler.

 

[cuinrearview]

+1 on the MM if it has the teeny little outlet like a 362 has.

 

[drf255]

Mufflers are a Beoch to mod, they need to be uncrimped or cut apart and rewelded to get that inner baffle out.

I haven’t had luck with timing advance on the model, but all the ones I did had chamber work to increase compression. A TA might work on a stocker, I’m just not so sure.

 

[cuinrearview]

Mufflers are a Beoch to mod, they need to be uncrimped or cut apart and rewelded to get that inner baffle out.

I haven’t had luck with timing advance on the model, but all the ones I did had chamber work to increase compression. A TA might work on a stocker, I’m just not so sure.

Sounds like a Dolmar muffler. I found a guy that welds them for me for $20. Can't beat that in my book. 45 seconds on a belt sander and it's filleted open, ready to mod.

 

[drf255]

I cut em in half. Still a PITA compared to other Stihl mufflers.

I tig braze them back together after i bolt the halves together. Braze flows faster, wicks in and takes less amps.

Unfortunately, the AM offerings have the same annoying baffle in them.

 

[SAWMIKAZE]

I've tried the gutted muffler and side outlet along with just drilling through the baffle and side outlet and there wasn't much difference if any on a stock saw.

 

[drf255]

Good to know.

Whats a stock saw?

Lol

 

[SAWMIKAZE]

Good to know.

Whats a stock saw?

Lol

What 99% of us woodticks use.

 

[Rick Stephens]

What 99% of us woodticks use.

Can't speak at all for anywhere except northern Idaho, but around here my guess is it's probably about 50/50. Busiest shops around are doing mods for loggers on mostly new saws. I was always amazed at the nearly instant word of mouth that gets around about satisfactions or the even faster with dissatisfaction on a mechanic's mods. From central Idaho all the way up to the Canada border, who is modding saws is on the tip of everyone's tongue. Want to get in a fight, bad talk the good guy or good talk the bad guy :^)

 

[SamT1]

I’ll definetly pull the muffler apart and do it right. Good idea on using the belt sander! It’s a shame a 360 muffler won’t work it would sure be easier to mod.
If I dont include a spark arrestor will that hurt the resale much if I decide to sell it?

I’m gonna set the squish to .020 or wherever it lands close. If I have to mill it down I will get it .018.

Ports will be cleaned up. Sometimes I get carried away, but I’m gonna try to do this one mild so I can sell it if I don’t like it and folks won’t think it’s a hack job.

I guess I’ll leave the timing alone for now since it’s not universally recommended like on some of the bigger saws.

I may do some math on the Oiler and see if I can go bigger. Some of you that follow my posts know I’ve had serious bar life issues in the wood I cut.

 

[SamT1]

Can't speak at all for anywhere except northern Idaho, but around here my guess is it's probably about 50/50. Busiest shops around are doing mods for loggers on mostly new saws. I was always amazed at the nearly instant word of mouth that gets around about satisfactions or the even faster with dissatisfaction on a mechanic's mods. From central Idaho all the way up to the Canada border, who is modding saws is on the tip of everyone's tongue. Want to get in a fight, bad talk the good guy or good talk the bad guy :^)

Has that always been that way? Guys modding saws? I didn’t even know it was a thing until a few years ago. Back when I made a living with a chainsaw I wouldn’t have even thought about tearing down a new saw to mod it. I thought I was a rebel pulling the spark arrestor out. Now I look back and can’t believe all the time I wasted on slow stock saws.

 

[Rick Stephens]

If I dont include a spark arrestor will that hurt the resale much if I decide to sell it?

Some of you that follow my posts know I’ve had serious bar life issues in the wood I cut.

I read some of those posts! What little manzanita I have been around doesn't seem to be chainsaw friendly. More something a metal cutting high speed bandsaw should do. I am amazewd at the stuff you cut!

On my own 361 I took a different path this time. I just welded over the exhaust port in the back and added two screened side ports. I didn't do the weld over and replacement to increase performance but to make sure I had spark arrestors on both ports. The muffler I have is AM and has no spark arrestor, and for me, I didn't see an obvious way to add one. I was sawing a bit late in the day once, while burning slash piles, and noticed a few sparks spitting out of a non-screened port. Those sparks traveled a long ways before going out. I can't afford to burn my place down. On a stock Stihl muff you don't have that problem and adding a second port with screen is easy peesy. I make up and sell a few on fleabay[URL="http://"].[/url]

 

[Rick Stephens]

Has that always been that way? Guys modding saws? I didn’t even know it was a thing until a few years ago. Back when I made a living with a chainsaw I wouldn’t have even thought about tearing down a new saw to mod it. I thought I was a rebel pulling the spark arrestor out. Now I look back and can’t believe all the time I wasted on slow stock saws.

I can't speak back terribly far. However, my daily grinder saw is a 440 that was modded 20 years ago by the now long retired local guy who would only touch a new unused saw. His thing was not to change RPMs a lot upwards and not increase compression because those two things significantly decreased saw life. So he opened saws up and had a reputation of building saws that just kept on running. I'm always running into people who talk about his saws from back when. I was not all that involved in the use of saws for more than firewood or storm cleanup until the last 5 years or so when I started logging my own place.. Which puts me in the rookie class still.

 

[Mad Professor]

Lakeside53/Andy's 361 muffler mod.

Pictures are long gone

https://www.arboristsite.com/community/threads/lakeside53s-361-muffler-mod-w-photos.33528/

 

[Mad Professor]

Anybody remember Lakeside53/Andy?

He knew more than most anybody here. Old AS members miss him.

Might be worth a look at the muf mod.
It was a tubing welded/brazed into the muffler that accepted a stihl blower spark arrestor. Could be directed at any direction. No need to split the muffler, gut the baffle from inlet side.

Too bad all those old pictures got trashed.....

 

[blsnelling]

I wouldn't touch the exhaust port just because the squish was tightened. That's not enough to matter.

 

[SamT1]

I wouldn't touch the exhaust port just because the squish was tightened. That's not enough to matter.

You’d just widen it some? If you had beginner/intermediate porting skills what would you do to the saw?
It will be worked under high load. But I generally rotate a few saws so it will get a good break. I’m in it for $200 so as long as it makes like 10k of wood I’m good. So I guess longevity is not a huge issue.