Modified Muffler ???

[YUKON 659]

I f I understand the previous replies in some past threads correctly, modifing a stock muffler is basically gutting the stock muffler and adding 2 port pipes. Is this correct? What , if any other adjustments need to be made? Will this be a noticable increase in performance?

 

[treeclimber165]

From what I've gathered here, I'd think that mods would be saw-specific. What works on a Stihl 026 wouldn't work on a Husky 357 or whatever.

Speaking of which, any specific advice on a 026Pro muffler? I'd like more power, not just more noise. I'd think if I cut out too much I'd get too little back pressure and lots of noise with little to show for it. How far should I go without going too far?

 

[deadtrees]

Does anyone have specific muffler mod advise for a Stihl 028 super?

 

[HUSKYMAN]

Brian I would ship that 026 muffler to Walkers. They put smaller ports on the smaller saws. When they did the muffler on my 55 it came out great, is not any louder hardly and screams. The ports are about 3/8" inside diameter. Now on the Jonsy 670 the put some huge 5/8-3/4" ports on it and that thing will wake the dead
The only thing is your saw will be out of comission for w couple of weeks
They are very reasonable also
If you try cutting your own ports it will end up looking like tundraottos 372 Thanks to Dennis for saving it

 

[builder]

What is the advantage of having pipes added over just opening holes? Also,any of you with 026's have any baffles? Got mine secondhand and had none.Was wondering if it came that way or somebody gutted it.

 

[HUSKYMAN]

The ports do a nice job of directing the exhaust away from the saw. Instead of all the heat blowing on the wood and coming back on your hand and the saw.

Dont be surprised about the baffles because most pro saws do not have them

 

[builder]

Anybody care to comment on the proper port size? I would think port area could be expressed as a percentage of the size of the exhaust port in the cyl. or maybe displacement? Am I right in thinking that the muffler port should be slightly smaller than the cyl. port? would the same size be the dividing line for "too much"?

 

[WOLF_RIVER_MIKE]

I don't know builder, Seems like your asking info that some people are making their living with.

 

[treeclimber165]

OK, let me be more specific. On my 026Pro (that I should have by Saturday), I want to boost power a little if I can. The saw has approx. 10-20 hours on it. I have a drill and drill bits, but I do not weld or have access to a welder.
1) What size drill bit do I use?
2) how many holes do I drill in the muffler?
3) where do I drill them?

I understand it's a little more meticulous than this, but I'm fairly handy with tools. Just looking for some guidance here so I don't screw up my new saw.

 

[builder]

treeclimber,I don't know if this will be optimum,but I know you'll notice a big improvement in power and it won't be too loud.
remove the front cover,look at it from the inside out,there is a hole about 3/8"with a screen behind it,that's all the saw has to breath through.drill another3/8" hole right above it,I left my screen in because it looked like new anyway. blow it out real good...don't leave any filings in it.maybe open up the slot behind the arrestor with a screwdriver.do a carb adjustment sequence and go cut some wood.Hope this helps.

 

[chainsawworld]

i can tell you this much. i put a walkerized muffler on one of my 371xp's the only carb adjustment i made was back the idle screw out. the following results were found

8x8 spruce stock all 20"fullchisel 3/8-7 rim 1 cut each
2.59,2.67
same as above with walkerized muffler
1.63,1.85

they are i little louder but seem to work; marty

 

[treeclimber165]

Thanks, builder. I'll give it a try. I'm also going to keep my eyes open for a spare 026 muffler that I might just send to Walker's- once I find out how much it will cost me. Wouldn't mind having a spare in case I screw up the origional one.....

 

[WOLF_RIVER_MIKE]

treeclimber, why don't you send a muffler to JW and keep one for backup. You can memick Walkers when you need to. kinda of like a blueprint.