660 Mod ?

[Ray Bennett]

I have read many post on 660 Muffler mods and want to make sure I have come to the right conclusion. I have a newer 660 with all the EPA devices. I think it would be best to completely remove the box on the inside of the muffler. Open the exhaust hole on the side of the muffler (because I do not want a Dual Port) Set the carb and go. Now my questions for those that have had both 066 and 660''s 1st, Can I just put an 066 empty can muffler on my 660? And second If I do that can I just set the carb to the factory recommended settings for the 066? I will of course check it with my tach but im just wondering if that should work. Any imput is appreciated, I dont need extra power (that is just a bonus) but I would like the saw to run cooler and last longer.

 

[Four Paws]

Open the exhaust hole on the side of the muffler (because I do not want a Dual Port) Set the carb and go.

Why don't you want a dual port cover? Factory or homebrew - it is a proven power adder!

Open the hole on the side of your muffler as large as you reasonably can - don't worry about going too far as there is not enough room to. Then, re-tune your saw to factory specs and adjust from there. Likely it will want to turn about 500 RPM more than where it was set before the muffler mod.

 

[Gypo Logger]

Sometimes you'll get an 066 that really wants to run like a couple I had, but sold. There's not much you need to do, cause the porting is right. I'd just increase the compression and do a muffler mod and call it good. It's mostly in the chain in the final analysis. Even though Stihl is better, the 385 shines and responds better to mods and could quite easily outcut the 066 in most cases, but what would I know, I'm just a woodtick and why wouldn't I be?
It's alot of fun though, this saw mod thing.
John<img src="http://img.photobucket.com/albums/v639/sunlover3/G2.jpg">

 

[Ray Bennett]

Why don't you want a dual port cover? Factory or homebrew - it is a proven power adder!

I cut a lot of stumps off near the ground and I hate the exhaust blowing up on me. I have a smaller saw with a dual port and I hate it for that reason.

Back on topic tho, Are you guys saying not to remove the box inside the muffler? I thought that was the main thing that needed opened or removed

 

[Lakeside53]

Boix - If you're concerned just drill the end out. It's there mainly for noise reduction and isn't very restrictive.

 

[Ray Bennett]

Boix - If you're coincerned just drill the end out. It's there mainly for noise reduction and isn't very restrictive.

Ok, If the box is not important should I just open the port or leave it alone as well? Im just looking to make the saw last longer

 

[Gypo Logger]

It's only a saw, and if it cuts fast and true then you're loggin!
Jo<img src="http://img.photobucket.com/albums/v639/sunlover3/1.jpg">hn

 

[JIMMYTreeWizard]

Can anyone post some pictures of the muffler mod and some of the other stuff mensioned?

 

[Lakeside53]

Do an AS search on "066 dual port" or "066 muffler" or similar... you'll get more hits than you can read tonight..

 

[tek9tim]

Yeah, the box is a bit of a pain to remove, but easy to drill. I'd only take it out if you ported out your cylinder and needed to match the port. My old metal tag, no epa, factory dual port 066 had the box in it, so I'm not sure they ever came without it. And the factory style dual port spits the exhaust out in the same direction as the stock exhaust port, so it doesn't blow up into your face like you describe. (just onto your hand when you have the clutch side up with a full wrap)

 

[slabmaster]

Heres a pic. of the last one i did.

 

[blsnelling]

Removing the basket and fire screen holder on my 066 was the hardest part of the job. Lots of grinding and prying and pulling.

 

[Lakeside53]

Why would you even bother takng out the fire screen holder? It's a huge hole...

 

[tek9tim]

Why would you even bother takng out the fire screen holder? It's a huge hole...

Just what I was thinking. Trying to make the outlet bigger than the port? Shoot, just take the front cover off.

 

[blsnelling]

Just what I was thinking. Trying to make the outlet bigger than the port? Shoot, just take the front cover off.

Not hardly. A 3/4" ID piece of conduit coming out at a sharp angle more than covered it. Two 3/4" pipes = 125% of the area of my exhaust port. One on each side.

 

[brncreeper]

Can anyone post some pictures of the muffler mod and some of the other stuff mensioned?

Here’s a pic back when mine was new. Factory DP that I ordered and had my dealer install it before I even picked it up. Part number is 1122 140 0603

 

[stihl 440]

066 mod

Here’s a pic back when mine was new. Factory DP that I ordered and had my dealer install it before I even picked it up. Part number is 1122 140 0603

This is my 066's muffler that I did....:greenchainsaw:

 

[slabmaster]

You can come out of the muffler base and not touch the cover.

 

[Lakeside53]

Here’s a pic back when mine was new. Factory DP that I ordered and had my dealer install it before I even picked it up. Part number is 1122 140 0603

Just to clarify for the assuming... that's the part number for the the entire DP muffler; not just the front cover.

 

[chrispy6822]

Not hardly. A 3/4" ID piece of conduit coming out at a sharp angle more than covered it. Two 3/4" pipes = 125% of the area of my exhaust port. One on each side.

I am looking at mod'ing my 66. Is 3/4" the reccommeded size for a 66 to keep it inline with the 80% to 85% of the exhaust port? Or for that matter does anyone know the size of the exhaust port on a 66?