Easy dolmar 5100/5105/510/460 muffler mod

[Sepia]

I have just finished doing this mod to my Maruyama MCV51. I didn't remove the interior plate, but did remove the cat. I drilled a second hole in the passageway that leads to the muffler exit. I am hoping this will provide a small improvement in flow while keeping the decibels reasonable. My main concern was getting rid of that source of heat inside the muffler. I didn't grind off the seam, but instead pried the overlap open with a sharp 1/2" wood chisel. It wasn't difficult and I didn't need to use a torch - just some patience and some muscle. One note in case it isn't obvious. Don't leave any thin burrs or thin edges anywhere inside the muffler when doing any grinding. They will get very hot and over time may break off and end up where you don't really want them. I kept the screen over the muffler exit for now, as well as the heat shield. I started it up in the garage and it isn't too loud at all, so I am quite happy with how it turned out.

 

[JoeMay]

Just got a new PS-421 earlier this month. Had the muffler apart because I've never had a saw with a cat in it and I don't mean the furry kind. What would be the appropriate steps and pics from above to just remove the cat?

 

[Ronaldo]

Just got a new PS-421 earlier this month. Had the muffler apart because I've never had a saw with a cat in it and I don't mean the furry kind. What would be the appropriate steps and pics from above to just remove the cat?

Normally you can dig the cat out of the back side of the muffler with needlenose pliars or something similar. It does take some patience and muscle to get started and then to remove all the pieces, but it works.

 

[Ronaldo]

Had my 5105H out on Thursday and cut a load of Elm and Mullberry and boy do I like the heated handles.Could , maybe spoil me and make me start wishing my other saws had such warm features!

 

[JoeMay]

Normally you can dig the cat out of the back side of the muffler with needlenose pliars or something similar. It does take some patience and muscle to get started and then to remove all the pieces, but it works.

Thank you. I just ordered a spot weld cutter. It was cheap and looks to be a useful tool. Wondering why I did not have one yet.

I've never had a saw with hot handle. My first saw was a Jonsered 451E and the alternative was the 451EV with the heat. Maybe should have done the EV and then been hooked on the heat. It is 22 below here this AM without wind chill.

 

[Ronaldo]

Thank you. I just ordered a spot weld cutter. It was cheap and looks to be a useful tool. Wondering why I did not have one yet.

I've never had a saw with hot handle. My first saw was a Jonsered 451E and the alternative was the 451EV with the heat. Maybe should have done the EV and then been hooked on the heat. It is 22 below here this AM without wind chill.

-15 here and not much wind. I'll help dad take care of the livestock, but my wood stack is ok for today. Going to be significantly warmer in a few days.

 

[Sepia]

Thank you. I just ordered a spot weld cutter. It was cheap and looks to be a useful tool. Wondering why I did not have one yet.

I've never had a saw with hot handle. My first saw was a Jonsered 451E and the alternative was the 451EV with the heat. Maybe should have done the EV and then been hooked on the heat. It is 22 below here this AM without wind chill.

When it's that cold I just stay inside. I wish that darn global warming would start kicking in!

 

[bang]

I split the muff by opening the crimp with a screw driver, a chisel and channel locks. Now I'm trying to decide if I want to do more before I put it back together.

 

[JoeMay]

I ended up just cutting the entire CAT cylinder and mesh out with a Dremel. The spot weld cutter was just too big to attack the welds in those close confines. Working with the Dremel and its attachments was even challenging. Got to watch the opposite side of the wheel when cutting to prevent inadvertently getting into the perimeter. I got into it a bit near the mount closest to the removed CAT (see attached). The saw is a bit louder and I had to retune a bit to get 13K on the tach.

 

[bikesandcars]

reviving a long dead post: I did a muffler mod on my 5105 a few years back... removed the cat and made a bigger exhaust hole, removed the screen (most Screens can be very restrictive, they block area and cause turbulence). Long story short, it was louder and made some more power. I got annoyed with the sound so I bought a 5100 non-cat muffler. the 5100 non-cat seems to perform just as well and is a bit quieter.

 

[a. palmer jr.]

Rather than doing all that modifying I just use an older muffler that isn't a cat, they fit and work better. It's the one with the horizontal lines on it.

 

[Jeff Lary]

I have been reading this thread I too have a PS-5105 new last January. Can someone give me some advice where to fid the non cat muffler that will fit this saw. I was reading a thread I made back when I first bought the saw and some were advising me to buy a 510 muffler now up above this post I am reading a 5100 is the muffler I need so I am a little confused.

 

[a. palmer jr.]

I have been reading this thread I too have a PS-5105 new last January. Can someone give me some advice where to fid the non cat muffler that will fit this saw. I was reading a thread I made back when I first bought the saw and some were advising me to buy a 510 muffler now up above this post I am reading a 5100 is the muffler I need so I am a little confused.

The 5100 and 510 are about the same as far as I can tell, I've had all of them and can't tell much difference. Just find an old Dolmar dealer and he'll probably have some junk saws along with the mufflers. The cat muffler has the swirl thing on top and the other is plain with horizontal lines. Here's a pic of mine:

 

[Jeff Lary]

yup ok,..I assume the High end will have to be opened up a little so I don't ruin the engine?

 

[a. palmer jr.]

My saw isn't modified except for the muffler, it's a 5100. I didn't do anything to the muffler except to swap it...

 

[Andrew Finley]

How do I contact Shaun for a muffler swap or modification to a PS5105H Muffler. Might as well eliminate this cat asap.

 

[cuinrearview]

I believe his screen name is srcarr52. Just start a private conversation with him.

 

[Andrew Finley]

Thank You.

 

[cuinrearview]

Thank you Nathan for this fine thread. Thought I'd bring it back up for newer members or those that struggle with the search function(looking at you, "LargeWilliam").

I have always swapped the older 5100s mufflers onto the newer saws. Personally, I like the look of the newer mufflers, but they get so hot and don't perform. Well, I'm getting low on 5100s mufflers and I have a pile of the cat mufflers. I finally got around to finding someone to weld them back up since I don't have the means. He did a great job and he's reasonable enough that I could probably help others out if they're looking to "de-cat". I completely removed the inner plate and spark screen, it's just a hollow can. I'll mount one within the next few days and follow up on noise.

 

[cuinrearview]

I got the muffler on tonight and made some cuts. One complaint folks have about these saws is the throttle response. It's quite sluggish. For that alone the modded muffler is worth it. It doesn't spool up like my small three series Huskies with an enlarged stock outlet, but it is much improved. It felt stronger in the cut as well. The noise is not an issue. I had a dual outlet ported 5100s that was pretty obnoxious, but this muffler is very livable. Honestly the most noticable difference is a little snarl at idle. I'm pleased with it.