help with 550 xp mm

[ash man]

I just got a 550 xp and from the research I've done seems like a mm is a good place to start. There have been some threads on this topic in the past and I think I like Brads approach of a 3/8 hole while leaving the baffles alone. Anything changed since that post, or any new input from anyone with something that's worked out better?

 

[ash man]

WOW tough crowd. Over 24 hrs and not one post. Well if anyone cares i did the muffler mod (3/8" hole next to the existing hole under the deflector cover) and put it back together tonight. I started up the 550 just to see what it sounded like and the AT seemed like it was having a hard time adjusting. I'm planning on taking it out in the morning and burying it in some wood for 3-5 minutes to see if the AT will correct itself. Will report back with results.

 

[KenJax Tree]

I opened mine up under the deflector with a Dremel and its pretty loud now.


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[ash man]

I didn't run it long, since I want its first run time wot in wood for at least 3 minutes to allow for the AT to hopefully do its magic, but in the limited amount I had it running tonight in the shop it didn't seem much louder. I didn't touch the baffles though.

 

[KenJax Tree]

I didn't either, but i opened it all the way up under the deflector next to the stock port. It sounds good though and screams at WOT.


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[mdavlee]

The 555 I did I gutted the inside. It was a lot louder with nothing in it.

 

[groundup]

I sent my 550 muffler to Randy, and it is a crazy beast now

 

[ash man]

I got the 550 xp out this morning and ran it hard for @ 5 minutes strait, and I could hear the AT adjusting during the run time. Seems like after about 3 big cuts in 20" oak it was tuned in pretty good. I kept running it wot for another couple of minutes to make sure. After that I turned it off and let it sit for a couple of minutes before firing it up again and it started on the 2nd pule on high idle. I didn't experience any bogging after letting it idle. SEEMS LIKE IT WILL RIVAL MY NE 346. I'm a happy camper so fare.

 

[fuzz1500]

I got the 550 xp out this morning and ran it hard for @ 5 minutes strait, and I could hear the AT adjusting during the run time. Seems like after about 3 big cuts in 20" oak it was tuned in pretty good. I kept running it wot for another couple of minutes to make sure. After that I turned it off and let it sit for a couple of minutes before firing it up again and it started on the 2nd pule on high idle. I didn't experience any bogging after letting it idle. SEEMS LIKE IT WILL RIVAL MY NE 346. I'm a happy camper so fare.

Sorry Im just seeing this now buddy ! Glad you got the 550xp going ! It takes a few cuts from a cold start for my girl's 550 to warm up and run right..then its smooth sailing till its time to shut down for the day !! Those 550's are very addicting..Im saving up for another one as we speak !!!

 

[sunfish]

The 3/8"+ hole under the flap is the way to go. No need to gut these muffs.

 

[KenJax Tree]

I didn't gut mine but its still pretty loud


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[DexterDay]

Any pics? I have my 550 Muff off now and I am wondering how you drilled the 3/8" hole?


Did you split the entire can open? Or just drill from the top on angle?

 

[KenJax Tree]

I took some needle nose pliers and lifted the deflector up it gives you plenty of room. I drilled a 1/4 hole so i could fit a Dremel bit in it. then i opened up everything to the right of the existing hole. I also was able to put the screen back in.


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[KenJax Tree]

Here is a pic:

I would say it was about 1/2 hole

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[DexterDay]

Great minds think alike. I went ahead a did it, then come back a read your post. Exactly what I did.

I blew it out with the compressor really good and then came inside and rinsed it out really, really good with warm soapy water. To remove any and all shavings.

 

[KenJax Tree]

Looks good. It will sound kind of mean now


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[DexterDay]

Looks good. It will sound kind of mean now


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I've never even started it. So I wouldn't know what it sounds like stock

Hoping it sounds good. The 545 I got from Ktoom sounded pretty good and it had a decent MM.

 

[ash man]

Sorry dex was away from my phone for awhile. I used tin snipes and cut on both sides of the deflector back some and then bent the deflector back, then drilled pilot hole then 3/8 hole with drill bit. After I was done I made sure there were no burrs left on the inside of the muffler with a file, and blew it out with a. ompressor then bent the shield back into place and tig welded the cuts. put the screen back in. Your guys method sounds easier, but I'm pretty happy how mine turned out to.

 

[coxy74]

Just a quick question about this MM, would this way be the same way to do one for a MM on 562XP??

Thanks

 

[ash man]

coxy maybe somebody else can chime in if I'm wrong, but I bought a 2260 from Terry Landrum and he modded the muffler in much the same way it appears. I put a 3/8" hole and left the baffles because of a post by brad snelling saying ihop that's what works the best, and I trust brads opinion.