Muffler mods.

[copedirector]

I've been scanning threads looking for instructions on muffler mods and cant find anything that does'nt confuse the heck out of me. What is the simple answer to hole/slot size and location without having to richen the carb too much? This is going to be done on my 026 and 044 for now.

 

[blsnelling]

You should always retune after a MM.

 

[timberwolf]

Simple answer on either the 026 or 044 is just make the standard outlet hole bigger. If you want to keep it mild on 026 drill 2 more holes one either side of the existing outlet. On 044 you need to grind the outlet hole bigger due to location. Making it about twice the diamiter will be a good start.

Just about any muffler mod will require adjustment to the carb settings, if it does not than it was run too rich in the first place. MM can be a good way to fine tune fixed jet carbs that are often over rich to start with.

On 026 you will want to check you have HS and LS adjustments on the carb before you start.

 

[Junkrunner]

You should always retune after a MM.

Why should you re-tune after a MM? I eat'em all the time and it doesn't seem to have any effect on the saw.:hmm3grin2orange::hmm3grin2orange:

I like the ones with peanuts!!:biggrinbounce2:

 

[scottr]

I've been scanning threads looking for instructions on muffler mods and cant find anything that does'nt confuse the heck out of me. What is the simple answer to hole/slot size and location without having to richen the carb too much? This is going to be done on my 026 and 044 for now.

For your muffler outlet try 80 to 85 percent of the exhaust port area measured at the cylinder wall.

 

[copedirector]

Is 80-85% a starting point or an ending point? That seems huge.

 

[pioneerguy600]

Is 80-85% a starting point or an ending point? That seems huge.

Ending point. My 044`s run two 5/8" exit holes.

Pioneerguy600

 

[njforestfire]

I know there is a percentage somewhere on this site that gives you the proper amount of back pressure needed for the saw to run properly. Not sure if 80 - 85% is right or not....it's been quite a few years since I did my mods. I could measure my modded mufflers and compare it to a stock to get my percentage. Now I am curious myself........

 

[timberwolf]

80-85% is in relation to the actual port at the piston, not the flange where the muffler bolts on.

85% is well within limits, problems don't often start until you are up over 125-150%. Depending on the saw and anything done to it if muffler openings get too big it can be hard starting and poor to idle.

Here is some testing done on 026 to give you an idea of how big you can go.
http://arboristsite.com/showthread.php?t=44816

440 muffler I did just the other week, it does have a extra large delfector welded on but not needed if you just open up the existing outlet hole. Hole is about 5/8 x 1.25 inches so easly well past 100% of the stock port.

Here is an 026 done with 2 5/8 pipes

066 a bit on the wild side, but works fine with ear muffs

 

[atvguns]

Why should you re-tune after a MM? I eat'em all the time and it doesn't seem to have any effect on the saw.:hmm3grin2orange::hmm3grin2orange:

I like the ones with peanuts!!:biggrinbounce2:

that's why the MM's melt in your hands before they get to your mouth cause your saw is running to hot with out a proper re-tune

the ones with the peanuts are the best if you get the plain ones you have to use a tack to tune your saw

 

[splitpost]

066 a bit on the wild side, but works fine with ear muffs

Thats insane,looks wicked:rockn: