Just picked up Dual port muffler cover for 460....?

[CaseyForrest]

I have a brand new 460, and just got the cover, and wanted to know if all those that have done the modification on their muffler with this cover gutted the muffler or just replaced the cover.

 

[bwalker]

If your 460 muffler has a basket over the exhaust port cut the end off it or remove it all together as the old mufflers didnt have this. Also open up the hole on the side to 3/4. This will replicate what the old school mufflers where like.

 

[CaseyForrest]

I guess I should have clarified. I got the Stihl cover that has the outlet on the front. I am going to replace it with the stock cover that has the hole on the side. I shouldnt have to add any holes or enlarge the one on the new cover, should I?

BWalker, I will check that out when I open the muffler up. Is that all I need to do internally to the stock muffler?

 

[fishhuntcutwood]

I am going to replace it with the stock cover that has the hole on the side.

The stock cover doesn't have any holes in it.

Jeff

 

[TRUSSMAN]

The stock cover doesn't have any holes in it.

Jeff

My cover didn't have any holes in it either.
Jeff

 

[bwalker]

I shouldnt have to add any holes or enlarge the one on the new cover, should I?

If you want to make it exactly like the old magnum mufflers you have to enlarge the hole on right side the muffler to 3/4. I am talking about the muffler itself , not the cover. You will also have to remove the basket that surrounds the exhaust port if your saw has one..

 

[CaseyForrest]

DUH...I just got it....It didnt hit me till JUST now that the stock muffler has the hole in it, not the cover...Ok, sorry for the brief moment of idioticy. On the same page now.

 

[shadyg]

Casey, you're best to do what Ben suggested with the muffler OFF the saw. If you have access to a milling machine removing the inner baffle is easy and for the side hole...open it up with a dremel, taking care as to open it up more towards the rear/ inside of the side deflector. You will also need to replace the gasket between the exhast port and muffler, so get one of those before you start to operate.

 

[bwalker]

When I open the side hole I used a dremel and a sanding drum and just moved it aorund the existing ccirlce till the hole was 3/4. The innner basket can be tooked off in short order with a drmel and a fiber cut off wheel.

 

[WoodTick007]

Part Numbers

What are the Stihl Part numbers for the Dual Port covers for the 044 and 066?

 

[TRUSSMAN]

What are the Stihl Part numbers for the Dual Port covers for the 044 and 066?

Part #1128 140 0801 about $30. This is for for the 044
Jeff

 

[fishhuntcutwood]

What are the Stihl Part numbers for the Dual Port covers for the 044 and 066?

I'm going to go pick up my new 660 right now...I'll let you know when I get back.

But I do recall there being a thread that mentioned the 066 DP cover. Try a search.

Jeff

 

[Onelick]

Once you open the hole to 3/4" do you have to readjust the carb settings?

 

[bwalker]

You have to adjust them. You should be adjusting them daily anyway.

 

[fullbore]

The part # for the d/p 046 cover is 1128-140-0801. The 066 d/p cover is 1122-140-0800.

 

[Lakeside53]

Has anyone actually done any TESTs dual port mufflers WITH AND WITHOUT removal of the internal box? The sum of the area of all the holes on the internal boxes I've seen exceed the opening area of most reasonable muffer mods... Stihl had internal boxes in many mufflers a long time before they started reducing the outlet for EPA.

 

[CaseyForrest]

I just replaced the cover today. I should have taken a picture of the inside of the muffler, but .......anyway, inside the muffler is what looks like a ramp. It starts at the base of the muffler, engine side, and comes about 3/4 of the way up the inside of the muffler, ramping out away from the engine. Its only as wide as the exhaust port, and with the saw at my eye level I could see into the cylinder. So I left it alone, and didnt open up the stock hole any, I figure just having the extra port on the front will give me all I will ever need with the saw.

 

[bwalker]

Has anyone actually done any TESTs dual port mufflers WITH AND WITHOUT removal of the internal box? The sum of the area of all the holes on the internal boxes I've seen exceed the opening area of most reasonable muffer mods... Stihl had internal boxes in many mufflers a long time before they started reducing the outlet for EPA

I havent as the 044 I put a dual port cover on didnt have one. I would think that having a box, regardless of the number of holes and their resulting area would have a negative effect on performance. A turbulance inducing devise so close to the piston is never a good idea.

 

[Lakeside53]

If it's "not a good idea" why is it put there? Particularly way way pre-epa?

 

[bwalker]

If it's "not a good idea" why is it put there? Particularly way way pre-epa?

Noise regs maybe?
Why did older GM trucks have fuel tanks mounted outside the frame rails?