I'm still around... (pictures added)

[FarmallTom]

I haven't really posted for many months but I lurk here every so often.
Today, however, I decided to speak up again with a bit of an update and also a question or 2.

Last Winter, I was in the process of upgrading my saw lineup and asked all of you for your input with that.  What I got was a great deal of insight and good guidance.

I think I mentioned back then that I had purchased a nice 460 Mag to go along with my 200T and 450 Huskie. (although at the time I mistakenly called it a 445, which is what my father has)
I LOVE that 460 and use it all the time with both 20 and 25 inch bars.  That old girl will eat up the Red Elm and Oak like none other.

Now then...
I recently decided to upgrade the 450.  I like the size of the 450 fine but, to me, it doesn't seem very torque-y.  By way of a replacement, I have purchased an MS260 which, by my calculations, should be about the same weight as Dad's 445 with the same relative bhp as the 450.  I'm willing to bet, however, that the Stihl's torque will surpass that of the Huskie.
What I am wondering is this....
Although I don't yet have the 260 in my posession, what upgrades might make this good saw even better?  Are there mod'ed muflers out there for the 260?  How much will that help it?  If I were to go for a muffler mod, would a retuning be required?
I'm not a small engine guy so I have to ask all these dumb questions...   

-FT

[Cut4fun]

No need to pay the stupid internet prices for a modded muffler you can do yourself with drill, dreme,l file, etc. Just open up holes or remove your inner cage if your saw has one. Open up exhaust outlet on cover 026260 has 3 different covers and back halves I think.
Yes re-tune carb a must. MM makes a big difference on the 026

[Al_Smith]

Oh man I don't know about  that .Gee wizz the way some of them talk a reworked muffler takes the understanding of a rocket  scientist and the skills of a heart surgeon to master .

Evidently the fairy godmother of chainsaws  has looked favorabley  on me all these  years because as stupid as I am I some how with blind luck get them all to work .

[Cut4fun]

Oh man I don't know about  that .Gee wizz the way some of them talk a reworked muffler takes the understanding of a rocket  scientist and the skills of a heart surgeon to master .

No words are needed to what I was thinking there Al. Bawhahahaha

   

[Bandmill Bandit]

2 cycle engines are pretty simple. The breath of life is AIR and the ability of the little PUMP to move AIR efficiently. It can be fairly complex when you are working to extract "another" 2 or 3% out of an already very well tuned PUMP. For most purposes just cleaning up the Exhaust FIRST and then INTAKE flow ports, tubes, and other after thought paraphernalia attached to silence, eliminate sparks, etc.  they will run pretty good.

The only thing to be really concerned about is maintaining proper back pressure from the exhaust system to ensure maximum fuel mixture flow to the combustion chamber there by maximizing combustion.

All motors are Air pumps! the better they can breath the better they preform. Intake is secondary to exhaust. No pump will take in any more than it can get rid of. This is the simple part and does wonders to help productive performance.

Once you start messing with back pressure, tune pipes/expansion chambers, port timing, schnurrle porting modifications, crank case stuffing, crankshaft vanes and balancing et ell, piston weight and piston head shape, cylinder head shape, compression ratios etc etc, you can spend a lot of money and chances are you will blow the little sucker to 7734 upside down in about 2 tanks of gas.

Its fun to do and if its a checkered flag you are looking for, worth it to your sponsor. This level of mods is complex and the only thing you gain when you venture to this level is and empty bank account and competitive performance (which can reload the bank with a good sponsorship deal). And the personal satisfaction of a very well done job when you hear it run and watch it smoke every body else competing against it. 

A competition engine only needs to last to the end of the competition. Dont know of too many competitions that last much more than a week end and any serious competitor will have a few built pumps sitting in the trailer for instant replacement WHEN the one he is using blows up.

Every motor I ever raced was out of the sled and on the bench for a thorough tear down inspection and TOTAL rebuild on Monday morning to make sure it was ready for the next weekend. Lots a fun and I got paid to do it for 3 winters.

About 30% of them blew up to the point of the scrap bin deposits.
     

       


   


 

[Cut4fun]

Lost me at the right turn Clyde.   

[FarmallTom]

OK - I see that maybe I need to clarify just what I am asking.
First, I have no desire to make a hotrod race saw out of it.  I didn't think I said anything to imply that but... 
What I was/am really asking is if a Mod'ed exhaust will help the 260 enough to be worth the trouble and expense.
I know something about engines and the whole "airpump" analogy... However, the ones I am familiar with have 4 to 6 cylinders, run on diesel, and have an IH on the front of them.
I know, from reading, enough about some of these saw mods to know that the fuel settings and back pressures can be an issue.  Also, since I have never even looked at a mod'ed exhaust for a saw like this, let alone MADE one, I prefer to leave such work to someone who knows what they are doing.  I don't really want to score the piston (or the like) in my "new" saw...
I wouldn't completely rule out doing the muffler work if/when I can find someone that would be willing to tell/show me in detail just how to do so.

I realize that to most of you guys such work is old hat and you think nothing of it but not everyone has done it a hundred times, ya' know?
It'd be like me expecting you all to know what the static pump timing should be on 560 Diesel... Or what the valve clearance should be on a 450...
 Some of you might know or be able to look it up but it probably isn't what you are familiar with...

I know enough to know when I don't know...!

-FT

[Al_Smith]

All you're doing with a reworked exhaust sytem is lowering the resistance on the exhaust side of the port loop cycle .On a two cycle you have to work backwards .If the exhaust can't get out the transfer of fuels can't get in .The whole system works on the differentials of pressure .It starts at atmosphere and ends in atmosphere 

The only way to make power is to burn fuel .If you alter the exhaust side of the engine it does become less efficient in it's use of fuel which I suppose some might find detrimental .Think about though ,it's a puny little saw engine like maybe at best is  7.5 cubic inchs .It's not like supercharged Rolls Royce Merlin in a p-51 Mustang or something that can burn more fuel in one take off than likely a chainsaw will use in it's usefull life time .

[FarmallTom]

Thanks, Al.
I understand what you are saying and I understand WHY the exhaust mod works.  I just don't know HOW it should be changed because I have never done one nor seen one done.
I also don't know squat about (correctly) setting the mixture to correctly compensate for said mod(s).
In addition, I have no way of knowing how I am affecting the aforementioned back pressures.

I think the bottom line is... I want it done right the first time.

One other concern is that although we have few saw shops within an hour or so of me, I don't know if there is any of them that I would feel confident with to tune an "altered" saw.
Most of them are shops that sell saws and do a bit of light service.

Example:

The closest Stihl dealers to me...
One is a True Value and the other one is a CaseIH dealership.
The third closest is an equipment rental place... 
None are mainline saw shops.
There is one place that MIGHT be OK...  It's an actual saw shop but it's and Echo dealership...

-FT

[man of stihl]

When you get the saw. Take a pic of the muffler and we will guide you through the process. If the 260 is like the 026, there are 2 or 3 different muffler designs. But it will be the same modification, drilling holes behind the deflector.

[Cut4fun]

Somewhere in this thread there is a 026 muffler I did. If the pics are embedded let me know. Because if your not a member you can only see the hosted pics and not embedded ones.  http://chainsawrepair.createaforum.com/stihl/stihl-026-pro-16/

[FarmallTom]

When you get the saw. Take a pic of the muffler and we will guide you through the process. If the 260 is like the 026, there are 2 or 3 different muffler designs. But it will be the same modification, drilling holes behind the deflector.

Thank you, MOS.
I'll have it in a few days, hopefully.  When I do, I will see about some pics and perhaps you can then give me the rundown on what we are looking at...

Somewhere in this thread there is a 026 muffler I did. If the pics are embedded let me know. Because if your not a member you can only see the hosted pics and not embedded ones.  http://chainsawrepair.createaforum.com/stihl/stihl-026-pro-16/

Cut4fun,
I am not a member so I'm afraid I am out o luck there...
I may join but... I think it takes a while to get verified anyway. 

Thanks guys.

-FT

[Cut4fun]

Your verified just sign in.

[FarmallTom]

Hrm..
I did log in and took a look...
Are the 2 small pics of an open muffler the ones you were referring to?
They are a bit small for me to see much but... perhaps they will mean more when I am looking at my own as well..?

-FT

[Al_Smith]

On sites with "thumb nail " pics just mouse click on the picture to enlarge it .BTW many use that type of format .

[Cut4fun]

Like Al said, click on the THUMBNAIL size pic to enlarge pic to regular size.  That just shows 1 of 3 type of covers. My back half didnt have a cage to drill out or remove.  There is 3 different back halves too. 

[w8ye]

The muffler mod just involves enlarging the outlet hole in the cover which amounts to removing the entire outlet recess in the muffler cover from the inside. On the 026, the outside of the cover prevents using a rattail file so it is necessary to use a burr in a grinder.

The job is not complete until you go on the outside of the cover and lift the outside shroud a little with a scrench, screwdriver, alignment bar, or something? If you are careful, this can be done to appear like it was done at the factory.

[Al_Smith]

So it's a sealed muffler I take it ? If that's the case you can take them apart which I've done and pinch them back together . Kind of a pain in the behind to do though .

[w8ye]

The few 026 mufflers I've seen have the typical Stihl removable cover but on the cover, the outlet has a hood that blows the exhaust towards the bar and then there is a ribbed and vented heat shield over the front cover.

There are some different designs on 026 muffler's though. There is one with the hooded outlet in the side of the muffler main body and another with slits in the side of the cover. These others generally have no screen accommodation.

[Cut4fun]

Simple 2 piece stihl design like you are used to Al.