Muffler Mod 575

[brncreeper]

Did this muffler mod yesterday. I made the mistake of trying to drill the spot welds on the deflector cap to remove it. Turns out it is electrically fused on so it will not come off easily. The 4 holes were just simply filled back in with weld. I have a Miller stick welder, but not a TIG. I cost 8 bucks to have a welding shop TIG weld the new cap back on.
I haven’t tried cutting yet, but it does sounds better!

 

[brncreeper]

 

[brncreeper]

 

[brncreeper]

 

[ispansco]

looks good!!

Fantastic work on the muffler and the good photographs. I see you have very good tools.

Congratulations by the final result. :greenchainsaw:

 

[brncreeper]

Thanks, I can't wait to get into some oak with it!

 

[asb151]

Maybe I missed it, but what size hole did you add?

 

[brncreeper]

I started off small and ended up with a half-inch hole. Actually 2 half inch holes total: one on the surface and one in the partition inside the muffler.

The 4 holes on the cap were a mistake and were later welded shut. I wanted to re-use the old deflector plate but could not.

 

[Four Paws]

FYI - there is a special bit for drilling spot welds but they are spendy. Another tool you can use is a die-grinder with a round nosed bit - 1/4" or larger in diameter works best.

Nice work on the muffler mod...take any before and after cut comparisons? Just curious what you gained. You probably could go larger and not hurt anything - maybe try a slotted hole up front, or another 'walker style' tube in the side if you are willing to go for more!

The finished product looks very nice - could pass for factory issue!

 

[minkota1]

Very cool! Nice set of pics, and nice looking job when done. By the way, what do you think of the 575? Seems like it gets a lot of bad press, but the guys who actually run 'em seem to like 'em. Sure love hear your opinion!:chainsawguy:

 

[brncreeper]

FYI - there is a special bit for drilling spot welds but they are spendy. Another tool you can use is a die-grinder with a round nosed bit - 1/4" or larger in diameter works best.

Nice work on the muffler mod...take any before and after cut comparisons? Just curious what you gained. You probably could go larger and not hurt anything - maybe try a slotted hole up front, or another 'walker style' tube in the side if you are willing to go for more!

The finished product looks very nice - could pass for factory issue!

Didn’t know about the spot weld removal bits, where do you get those? I haven’t got out to test it yet, it’s been pretty muddy from all the rain we’ve had. I could have opened the exhaust more, I thought I’d try a little to start with. I wanted an edge in power when going from a full skip to a full comp chain. I like the “stock” look.

Very cool! Nice set of pics, and nice looking job when done. By the way, what do you think of the 575? Seems like it gets a lot of bad press, but the guys who actually run 'em seem to like 'em. Sure love hear your opinion!

The 575 works for me. It used to start hard when it was new, but now it’s fine. It pulls a skip chain on a 28” bar just fine. The skip chain tends to catch and jump off the bar though. I thought I’d try the Cannon/WoodsmanPro bar and a full comp chain to see if that cures the problem.

 

[bouden]

User view

I'll defend the 575. I have both the 372 and 575, and put lot of hours on both. Yes, it is a little heavier, but you really don't notice it in the woods. Yes, it does take longer to warm up, but afterwards it will start at idle all day. There may be an issue with the bearings, mine went out (both sides), but not major failure, and the one plastic ball retainer that left the saw did no damage to the top end. Now for the little things I like: The oversize rear handle is really comfortable in my big hands. Sounds stupid, but much less fatigue. (The soft patch on the handle is starting to wear off though) I like the return to a one piece top cover. You are much more inclined to clean the cylinder and not just the air filter. It does have more torque in the cut. There just are not as many chain stalls as the 372. However, neither will hold a power candle next to my 7900, at approximately the same weight and size.

I'm glad to see a venture to mods on the 575. We will all have to learn the nuances of the stratified-charge engines, as this seems to be the coming technology. My saw is bone stock. When I had it apart, I was afraid to start taking on the challenges of the dual air path. I do think the muffler is restrictive, and heavy! The baffle that was drilled through in this tread adds weight and chokes the flow. A Walker-style pipe on the outside would do minimal good without dealing with the baffle. Nice job on this mod. Others??

 

[Four Paws]

Didn’t know about the spot weld removal bits, where do you get those?

The spot weld removal bits were something I discovered while working in a bodyshop a while back...the guys that got the heavy hits used them quite a bit. Seems like they bought them off the tool truck. I bet a google search, or a trip to Snap-on, Matco, Cornwell, etc. websites would yield good results.

 

[brncreeper]

Gave it a good workout yesterday, power was excellent even with a full sequence chain. Blocked out this old cotton wood stump with ease. Had the 28 bar buried but still pulled strong. The sound is much better too!

 

[shawn.m]

eastwood.com for spot weld drill bits

eastwood.com for spot weld drill bits

 

[IchWarriorMkII]

Lookin good, nice work and nice pics.

 

[TDunk]

+1

 

[ASEMASTER]

nice job

I did a mod on my new 570 cut out the baffle, drilled the top outlet and added a 5/8" pipe to the right side facing the bar as I get more hrs. on it it is starting to wake up and really cut the hard wood. also adjusted the carb set by ear .

 

[wipikas1]

nice pictures but slow on dialup

Brncreeper,
in the pic after the final drill, what is that second hole deep inside the muffler that was drilled?
If I wanted to do this to my 357xp would it have to look the same and would a new pipe have to be inserted through both the inside hole in the muffler as well as the hole on the surface then TIG welded? thankyou

 

[brncreeper]

Brncreeper,
in the pic after the final drill, what is that second hole deep inside the muffler that was drilled?
If I wanted to do this to my 357xp would it have to look the same and would a new pipe have to be inserted through both the inside hole in the muffler as well as the hole on the surface then TIG welded? thankyou

Sorry about the slow dial up speed. I did re-size all the pictures before posting which should help with your slow connection. The hole inside the muffler is the ½ inch bit through the baffle as well as the outside of the muffler. I’m not sure if your 357 would even have a baffle, my 346 did not have one.

With the 575 muff, I wanted to drill perpendicular to the baffle that’s why I made the jig to hold it at a 45 degree angle.

Anyway if yours does have a baffle, then drill your two holes and weld your pipe on the surface hole. I like TIG welds but you may be able to silver solder it on yourself.

I wouldn’t try to pipe down to the new baffle hole. In my opinion it would be a lot of work for nothing.

No rules for muffler mods, the baffle does need to be bypassed though.