Husky XP 550 Muffler mod completed.

[Tollster]

After about a month and a half I decided to modify the muffler. I found throttle response has improved, top end has no limit, and no loss in torque. The autotune adjusted very fast to the point that I only saw improvement, and that was within the first half tank if that. With this mod I have found myself backing off threw top end when not needed just to save wear and tear on the rings.
I honestly did not think it could not be improved upon. Took about 15 minutes, muffler hex nuts where easy access using a "T" handle, only had to remove top air cover.

Although not visible in this image, the hole is tear dropped shape, the narrow portion is hidden by the heat shield in this image

I was able to retain the spark arrestor screen for a clean look, it is louder than stock, how much is hard to say, but I would say its 1.5 times as loud. This has been repainted using BBQ flat black, I can not feel any heat being projected onto the brake handle or air filter cover, which was a concern I had since this it not under the deflector.

I used my dremal cone burr for all work, no drill bits, as I did not want to twist the metal, the cone burr cleared the heat deflector with very minimal damage only do to human error (if you won at operation when you where a kid, you're set!), the barrel burr would not clear the heat shield, only the cone burr would.

Tol

 

[Bluegill2]

Cool! Nice clean work...

 

[stormpetrel]

Yes, what Bluegill said!!! Nice job....neater than my own (I used a drill first, then cleaned up with a burr)

How much have you used your saw? I just finished tank #13, and I modified the muffler before I even started the saw. It has power to the point that I am literally smiling as I work!! I have not been splitting any wood; rather, I have placed the rounds on a stump and "noodled" them into some of the prettiest, easiest-stacking firewood you have ever seen. FAST.

 

[Tollster]

Its been two weeks since I ran it, the snow is about a foot deep so I figured I would wait till it melts down some. I tried to get up to the property today and fell short due to the deep snow. I will focus on burning the piles I have made before I cut anymore.
I love my new saw and so happy I got it, could not have asked for more, its just what I needed and I love the light weight and the power to weight ratio, my back can tell a difference after a full day. I am running a stihl full chisel on my 18" bar, some of the shavings are close to 2" long on the hemlocks.
I am on my 2nd can of 2.5 gallon premix

 

[stormpetrel]

Its been two weeks since I ran it, the snow is about a foot deep so I figured I would wait till it melts down some. I tried to get up to the property today and fell short due to the deep snow. I will focus on burning the piles I have made before I cut anymore.
I love my new saw and so happy I got it, could not have asked for more, its just what I needed and I love the light weight and the power to weight ratio, my back can tell a difference after a full day. I am running a stihl full chisel on my 18" bar, some of the shavings are close to 2" long on the hemlocks.
I am on my 2nd can of 2.5 gallon premix

I run an 18" bar too, and find the balance is perfect. Quite a step up from my old 445 xtorq!!! I'm pondering sending it out for a porting job; I would buy a 562XP, but times are a little hard.

I notice that I can have the bar completely buried in hardwood (I'm cutting cherry now for next year) and not bog the saw at all. Really impressive! And I think it still has a little more "tightening up"to go as far as break-in goes.........gonna give porting some serious consideration. Once I'm done with the saw for the season that is....

Oh, and the 550 is the same size and weight as the old 445. It's like I'm in some other dimension where saws are twice as fast or something!!!

 

[Scooby074]

Any idea how the 562 would respond to a MM? Id imagine about the same as the 550 since they are so similar?

 

[Bluegill2]

Any idea how the 562 would respond to a MM? Id imagine about the same as the 550 since they are so similar?

I did a MM on my 562 for a good gain in power. Although it really didn't need it.

 

[stormpetrel]

Any idea how the 562 would respond to a MM? Id imagine about the same as the 550 since they are so similar?

I looked it upon AS, one builder said he takes the muffler apart and removes the baffle, then welds it back together. I only read the one guy's opinion, nobody else talked specifics. Seems like it might be more complicated than the 550 MM....? As far as I know the results are similar, most 562 owners say the saw will cut with a 372 no problem in up to 24" wood(!). And that's w/out touching the muffler. Someday......

 

[stormpetrel]

How does the mod itself work? Same as the 550? Got any photos?

 

[stormpetrel]

Here's a thread about a 562XP mod w/muffler photos. One guy says improvement up to 20% with just the MM!!!
http://www.arboristsite.com/chainsaw/203790-5.htm

 

[Bluegill2]

I cut the baffle out through the inlet opening, with a carbide burr. Then got the rest out through the outlet. Had to cut the deflector and bend back out of the way. Once done welded the deflector back.

 

[Scooby074]

Here's a thread about a 562XP mod w/muffler photos. One guy says improvement up to 20% with just the MM!!!
http://www.arboristsite.com/chainsaw/203790-5.htm

Wow!. Was that 20% with just the muff mod? You sure? If so, thats reallllly tempting.:licking:

The 562 after all the cyl mods Stumpy did to it is sure a sexy beast! But if I can get 20 with just the muff, thats impressive too! I was also real impressed at the stock 562 with the 28" bar .

 

[Bluegill2]

The 562xp is by far the most impressive stock saw I've ever run. I have owned and run a bunch of highly modded saws. It doesn't need a MM or porting at all, but gains are there if one wants.

The word on the street is the 550xp doesn't need porting, it runs like a ported saw with just a MM.

I live about an hour north of Stumpy and he is doing great work these days. He built my 75cc 365xpw and it is a beast!!!

 

[stormpetrel]

The 562xp is by far the most impressive stock saw I've ever run. I have owned and run a bunch of highly modded saws. It doesn't need a MM or porting at all, but gains are there if one wants.

The word on the street is the 550xp doesn't need porting, it runs like a ported saw with just a MM.

I live about an hour north of Stumpy and he is doing great work these days. He built my 75cc 365xpw and it is a beast!!!

I am torn between wanting another, larger chainsaw, and having my 550 ported. For around $200 I can buy (a) a used 285XP (b) a 70cc Jonsered or (c) have the 550 ported. Thoughts? (it already runs pretty incredible with the MM and having run 14 tanks of fuel though it...seems like the most bang for the buck would be porting?)

 

[stormpetrel]

The 562xp is by far the most impressive stock saw I've ever run. I have owned and run a bunch of highly modded saws. It doesn't need a MM or porting at all, but gains are there if one wants.

The word on the street is the 550xp doesn't need porting, it runs like a ported saw with just a MM.

I live about an hour north of Stumpy and he is doing great work these days. He built my 75cc 365xpw and it is a beast!!!

I am torn between wanting another, larger chainsaw, and having my 550 ported. For around $200 I can buy (a) a used 285XP (b) a 70cc Jonsered or (c) have the 550 ported. Thoughts? (it already runs pretty incredible with the MM and having run 14 tanks of fuel though it...seems like the most bang for the buck would be porting?)

 

[Bluegill2]

I am torn between wanting another, larger chainsaw, and having my 550 ported. For around $200 I can buy (a) a used 285XP (b) a 70cc Jonsered or (c) have the 550 ported. Thoughts? (it already runs pretty incredible with the MM and having run 14 tanks of fuel though it...seems like the most bang for the buck would be porting?)

Tough call. I like smaller high performance saws much better than heavy bulky 70cc+ saws. But that's just me...

 

[Bluegill2]

Second thought, I'd just send the 550 to Stumpy and be done with it.

 

[arrow]

I am torn between wanting another, larger chainsaw, and having my 550 ported. For around $200 I can buy (a) a used 285XP (b) a 70cc Jonsered or (c) have the 550 ported. Thoughts? (it already runs pretty incredible with the MM and having run 14 tanks of fuel though it...seems like the most bang for the buck would be porting?)

First, I'd leave my 550 alone. The MM is enough in my mind. Depends on what you're cutting. If its always firewood type, just stick with the 550. If you are in the woods harvesting your own trees, I love a big saw to stump with. I had a 385 just for that purpose but got rid of it just after a year as it didn't have that much more grunt than the 372 for the weight difference. I'd always opt for the larger saw if you need a torquey larger cc saw for such things as bucking and you do not want to switch bars. A 16" bar on a 70 cc saw is a wonderful thing for such work.. Don't forget its more than just speed and power of a chainsaw its also technique of cutting and operating a saw just right in its powerband. That comes with experience where you can out cut many a larger saw wielded by less than knowledgeable.

 

[plasmaguy]

Hello guys,

I am coming in on this thread way late. I just bought a 550 and have run two tanks of fuel through it and I'm ready to mod this muffler.
I modified my 345 years ago by welding a stub of 3/4" EMT conduit.
I like being able to use a carbide to enlarge the opening.
How much larger is the exhaust opening? The screen makes it hard to tell.

Thanks,

Tom

 

[Bluegill2]

Tom, just do like the OP did. Open up another hole next to the stock hole under the deflector. Make it as big as there is room for. No need to get all crazy with it.