?Run 40:1 in 359 Etec?

[555JM]

Hi,
New to forum; first post.

Been cleaning up some 20 to 30 inch trunks with my "big" saw, a new Husky 359 Etec with 24" bar. Visited the local saw shop to pick up my Dolmar 401 yesterday and got to talking with the owner. He thought I was pushing the 359 pretty hard with the 24" bar and told me to go easy.

What he said made sense. This is my first Husky and I've been running it by the book using Husky XP oil mixed 50:1. I started thinking about running a 40:1 ratio while working the 24" bar, but then remembered the environmentally correct muffler. If I go to a 40:1 mixture will I damage or clog the muffler?

The shop owner showed me a small screen he took out of a new style muffler. It was all clogged with carbon. He said when this thing clogs it can result in a lot of carbon staying in the cylinder and causing scoring. Of course I want to avoid that and figure 40:1 would clog it quicker. Is there an easy way to get that screen out and avoid the problem?

Is Husky XP oil a good choice? I've got that and Poulan 2-stroke oil on hand; anything better? I'll probably put the 20" bar on when I finish up the trunks but might stay with 40:1 mix

Also watching Rudolphski's thread on modifying the Etec muffler with interest.

Thanks.
Bob

 

[timberwolf]

I would run 40:1, a new muffler costs less than a jug and piston.

I would also open the muffler up, saw can pick up over 30%, then you don't have to worry about 40:1 causing the cat problems.

I have found both husky and stihl oil left lots of deposits, new castor based and synthetic oils may be better in terms of deposits and protection.

 

[Heilman181]

I had my muffler modded by Rich Hoffman (rahtreelimbs) and run 32:1 Mobil 1 2T synthetic. Night and day difference!

 

[buck futter]

the 24 inch is pushing it but take it slow, keep you chain sharp and make sure she doesn't lean out. you may want to go to a semi skip chain. You can also break up your blocking by letting cut some small wood to cool down between cuts. Essentially a lower duty cycle of full power cutting.

By adding more oil to the mix is normally a good idea, ( I run 40-45:1) but it may add extra heat with the cat. Husky oil is just fine, not the absolute best but it is decent quality. I think you should do what TW said buy another muffler and muffler mod it, at least gut it.

You might even find someone on here that can provide you with parts for your 359. :yoyo:

have a good one

 

[timberwolf]

You need to wrestle your own waranty issue here if that is a importaint point for you. Opening the muffler will require clipping the carb limiter caps, both could give the dealer the grounds to walk away from the waranty.

But the dealer can always claim you were using an un recommended bar and overheated the saw, had bad gas, did not mix enough oil, bla bla bla...

 

[bwalker]

I ran my 346 etech on 32:1 for about 2 gallons of fuel with out issue. I did mod the muffler first though.
With that said take the etech muffler and throw it as far as you can. The CAT makes the saw run too hot, even after its modded. A new muffler is only $45 and the saw will run better witha traditional hollow muffler.
Husky silver bottle oil is good oil and bunrs very clean at 32:1.

 

[Luke]

Etec Trivia

Got a extremely detail oriented engr friend. He bought an 359 Etec and was a little dissapointed in the performance. He decided to try to get a muffler opening that would be 80% of the exhaust port. He actually counted the little holes in the cat, measured them and calculated it had .2 something inches ^2 of total cross sectional area! He cut open the muff, gutted it, rewelded it, and opened the exhaust to 80% and is now very pleased.

 

[555JM]

Thanks for the help

Thanks to all for the replies and the information.

Ben Walker: Where would I find a hollow muffler? Do any of the site sponsors sell saw parts outright? I assume you're talking about a pre-Etech 359 muffler.

Cutting and gutting sounds like a good idea, but I'd prefer to hold off on destroying something I paid good money for. Would be OK as a last resort.
Bob

 

[timberwolf]

You might find a used one if someone is parting out a saw. But other than that go to a husky dealer, may be best to go to a different one, order a muffler for and older 359 non etech.

Luke, lots of small holes don't equal the area of one large hole. as there is more resistance to flow near the edge of the hole the more holes there is the more edge. a 1 inch hole has an edge length of 3.14 inches and an area of .79 in2, two holes with half the area .39 in2 and .71 inches in diamiter have an edge length of 4.4 inches. the more smaller holes of the same total area the less the flow.

 

[buck futter]

inside you will see a pipe that goes from in front of the waffle plate to the back, cut that pipe out and put a whole in the front bracket into the muffler can. I also drilled out a bunch of the holes in the waffle.
The other way is to take a 3/4 inch hole saw and go through the front and through the waffle plate. this will eliminate more of the plate and she will run cooler.

There is more than one way to skin a cat.

 

[bwalker]

Putting holes in the CAT plate doesnt solve the problem as it is still generating heat. The plate itself actually glows red hot when the saw is operating.

 

[Urbicide]

The Husky part # for the non-cat muffler is 503 91 75-01. If you do not have a local source you can always get Husky parts through Bailey's.

 

[Luke]

Thanks TW

Thanks TW, I thought that if you took a summation of the cross sectional areas of the individual holes and it was "X", that was the same as an individual hole of "X" cross sectional area.

 

[555JM]

Thanks loads Urbicide

Thanks for the part # Urbicide. I can get something started with that.

I'd rather leave the CAT muffler alone for the time being. If the environmental police jump out from behind a tree, I can always confess my sins and slap it back on.
Bob

 

[outdoortype]

E-tech Muffler?

If I replace the e-tech muffler with a non-cat muffler should I richen the Hi speed Jet? Would just the non-cat muffler alone make a difference in engine temp/longevity or should I just plan on modifying it to begin with? I'm trying to gain longevity more than performance without a huge gain in sound level(if possible). Any suggestions?

 

[buck futter]

pull the screen out of it for a little more flow.. yes it will run cooler simply by not having the catalyst material in there. you may be able to reach inside and widen the original hole, honestly I haven't tried it yet. I think you are a lot better off already.

buck

edited to add

on adjusting the carb, does the saw still 4 stroke at wot? does it accelerate and idle well? that is the simple test.

 

[Urbicide]

Reply to outdoortype

Welcome to AS. By replacing the cat muffler with a non-cat muffler will enable your saw to run cooler. Therefore it has a better chance of living to a ripe old age. As far as richening up your carb goes, I think possibly your best bet would be to borrow or buy a tach. Use it to guide you in any adjustments. 13,500 rpm with bar and chain installed maximum speed. As far as noise levels go, the more you modify the muffler, the louder the resulting noise level will be.
opcorn:

 

[outdoortype]

Thanks for the info

Urbicide & futter,

Glad to be a member of this forum. Thanks for the information. I'll probably wait until the warranty expires (this january) before I mess with it. I might grab up a non-cat muffler before then. The engine 4 cycles @ 3/4 throttle & I think @ full throttle. Although I was scared to hold it WOT for very long the other day because it was 70 degrees F out here. I've checked the spark plug about 3 times in the last two years & it varies from dark brown to dark tan to black.

555JM -I've been running 45:1 for almost 2 years now(machine has 18 hours) & haven't noticed any build up in the muffler screen.

 

[bwalker]

Setting the carb richer on a saw with a CAT will cause it to run much hotter as the excess fuel is burnt off by the CAT.
Ditch the CAT muffler ASAP.

 

[Evin]

Muff Job 359 Saturday

Well I just did my mod on my E359 this weekend. As I did not know the easiest way to separate the muffler I took my drill and drilled away the waffle which I think contained the catalyst and drilled a hole into the pipe that hooks up to the original outlet. I made an half inch hole through the front above the muffler bracket. I originally tried to use my mapp gas torch to braze on a square sheet metal cover for the screen on the front...but it was to broad of a flame. I then ran down to the Lowes store and got a cheap mapp/oxygen torch $50 and finished the job. Sunday I went and got a gallon of 91 octane gas and made 40:1 using Castrol 927....WHAT A DIFFERENCE!!!! I tried to use an exacto blade to cut off the limiters so that I could richen up the mixture, but I think I will have to do a better job as it does not move very freely. The stock 359 was barely an improvement over my 51cc 55 Husky, but now I am a happy camper..... :biggrinbounce2: