550XP Muffler Mod Thread

[procarbine2k1]

I have seen some 550XP muffler pictures and ideas floating around here a bit, thought we could condense and have a thread for your modification/ how to/ results.
I will try and get a couple pics up of mine this week sometime. I finished mine last night, took some pictures with my cell, but need to purchase another phone card to transfer them to my pc (I dont have a text or email plan).

I cut my deflector off of the muffler, (like opening a soup can) and drilled a 3/8 hole next to the stock outlet. Cleaned this additional port up, welded the deflector back in place and added a flap to extend the deflector. Performance gain is far beyond I have seen with any other muffler modification on other saws I have seen or done. Im into stock appearing, I fought with my welder a little last night, so ended up with a grinder in my hand as well. I really need to get my table up to this shop, its a real treat not having the work area to weld in. Looking forward to gathering up some pictures and or ideas. Hope some of you guys chime in.
Feel free to post up times/ gains.

 

[Hermann]

:msp_drool:

opcorn:

 

[blsnelling]

Like I mentioned in another thread, this is one saw that I can't see selling a port job for. Most of the gains are right in the muffler mod. With a burr with a 1/8" shaft, you don't even have to cut and weld the baffle.

 

[mweba]

Like I mentioned in another thread, this is one saw that I can't see selling a port job for. Most of the gains are right in the muffler mod. With a burr with a 1/8" shaft, you don't even have to cut and weld the baffle.

Yup, get in there without cutting the deflector.

They once said gains were not worth the trouble in the 7900.

 

[blsnelling]

They once said gains were not worth the trouble in the 7900.

This is true

 

[Tzed250]

Like I mentioned in another thread, this is one saw that I can't see selling a port job for. Most of the gains are right in the muffler mod. With a burr with a 1/8" shaft, you don't even have to cut and weld the baffle.

My 550 was much stronger ported vs. just MMed. Remember when the 441 was junk because it couldn't be modded?

The easiest way to get good gains to the 550 muffler is to cut the two sides of the deflector with snips, peel it back, then port the can. Bend the flap back down and TIG weld the seams. Less than 1/4 inch of filler rod used. Pics from a mod I recently did for a member here:


Untitled by zweitakt250, on Flickr


Untitled by zweitakt250, on Flickr


Untitled by zweitakt250, on Flickr

 

[Jet47]

I simply added another port on the starting side of the muffler. Saw responded very well.

 

[Tzed250]

My reason for not adding a port on the left hand side is that I don't want the gasses vented closer to the operator or toward the wood. Plus, some folks like the muffler to retain a stock appearance. The customer in my post desired just that.

 

[Jet47]

My reason for not adding a port on the left hand side is that I don't want the gasses vented closer to the operator or toward the wood. Plus, some folks like the muffler to retain a stock appearance. The customer in my post desired just that.

Good points.

 

[procarbine2k1]

Like I mentioned in another thread, this is one saw that I can't see selling a port job for. Most of the gains are right in the muffler mod. With a burr with a 1/8" shaft, you don't even have to cut and weld the baffle.

I wanted to have a good look inside, and have a little room to work. Turned out nice and clean (I might be a little on the OCD side on muffler appearance), a little on the loud side though... And I definitely agree with you 110%, these saws REALLY respond to a little muffler work. Spent a little time in the woods with it yesterday. Hands down the most impressive saw for the size I think I have had my hands on.

 

[rullywowr]

Totally agree with the above (under the deflector method). Pull muffler, pull screen, pull the hood up a little bit and sneaked in a 3/8" drill bit at an angle under the deflector to the right of the original port. Get all chips out (important!) and replace screen/muffler. Worked really well and a noticeable improvement in performance and overall "attitude." I did catch the drill bit ever so slightly on the deflector and knock off a little black paint on the deflector but this is my firewood workhorse and not a ladies handbag.

 

[TermiteBuffet]

i just did my 550 lifted the deflector and removed everything on the right of the exit hole , with a dremel i'm now wondering if i left power on the table?:msp_mellow: by not gutting the whole thing ,has anyone done the small hole , ran it and then went back and gutted inlet and outlet? If so were gains noticed ? I did my 562 the other night , i took all i could reach with a dremel out inlet and outlet , it's basically a can now :msp_thumbsup:gonna put them both in the wood tommorrow, morning ,Unless ya'll talk me into going back into the 550 muffler then i'll be slightly delayed ? Advice? Questions ? Comments ? Termite

 

[Joe Kidd]

In regards to the 550, I think we've found that a gutting will only make it louder, but some others may input on this.
The 562 will sound like a nitro burner. :msp_thumbsup:

 

[Tzed250]

What Jeff said. I think I've done five of them now and so far all are happy. The inlet is a fairly open design so I don't think it is a roadblock. If there is more power left in the can I think it would come at the expense of massive noise.

 

[TK]

The MM does a good thing for the 550, more than just noise

 

[komatsuvarna]

I probably didn't gain anything by doing it, But I gutted the hell out of my muffler. Took 90% of the baffle out and took the pipe thinggymajig out too. Opened it up all I could and still keep it under the factory deflector. It's no louder than my other saws and isn't much louder than a stock 550. Also still running the OEM spark screen.

Took awhile to get all that crap out too!

 

[blsnelling]

I opened up the baffle quite a bit and only made the saw louder.

 

[Joe Kidd]

In my personal comparison, I believe the 562 muff has more restriction than the 550 and can benefit from removing inlet and outlet baffle material. Also the fact you've got 10cc more puke to dump!

 

[TermiteBuffet]

What was funny i was making my first grinds/ cuts on the 562 muffler and the bit came out and fell into the muffler dang that was kinda tough getting out now i can drop a marble in it and will roll right out .....And Joe that 562 does sound like a top fuel car We must come to a conclusion here...... the muffler is at ya'lls mercy...... i did fire the 550 this evening [ for the first time ] sounds good got a nice crack/ pop to it. Termite

 

[TK]

I've heard of some sweet gains on a 550 ported as well. The words used may or may not have been "keeper" and "stopwatch." Time will tell. No it's not mine. But mine maybe next....