Modding an Old, Much Used Stihl 028 Super

[husky362]

I used to Ride 4 wheelers around old salem Hodge Rd a lot of good times on that bluff ....There was some good Trails before they cut trees off it
Have not been there in years

I still have a 4x4 just not that one don't get in much mud now.. it's soggy here too we get your saw fix we can cut wood anytime
I've got die grinders too if you need them... step drill bits can work In some places

 

[Frogfarmer]

A muffler mod will wake it up quite a bit. I also have found a timing advance helps a great deal too. I've recently had to go through several 028s and all had at least one bad seal. Food for thought.

 

[GypsyCliff]

A muffler mod will wake it up quite a bit. I also have found a timing advance helps a great deal too. I've recently had to go through several 028s and all had at least one bad seal. Food for thought.

Looks like you like them there Stihl saws. Me too, though not into making a collection. My saw runs well, just thought it would be fun to soup it up a little bit. Not trying to make a killer, just hotter.

Thanks for your input.

Cliff

 

[Frogfarmer]

The last super I put together was very strong. I had all but given up on the 028s because the 026s run faster and lighter. They are a classic that just keeps going and going.

 

[GypsyCliff]

A muffler mod will wake it up quite a bit. I also have found a timing advance helps a great deal too. I've recently had to go through several 028s and all had at least one bad seal. Food for thought.

So just exactly how does one do a timing advance. I know nothing. Thank you.

Cliff

 

[drf255]

So just exactly how does one do a timing advance. I know nothing. Thank you.

Cliff

You have to pull the flywheel and the key from the crank, file .025 off 1/2 the depth of the key on the Right side as you look at it (Base needs to stay the same so it fits in the key Way), then reinstall the flywheel correctly. Using a rope as a piston stop, put the flywheel and nut on over the crank with the key installed. Rotate the flywheel all the way counter clockwise using the flywheel to do so. Hold the flywheel counterclockwise with you hand only and snug down the nut. Then, without touching the flywheel with your hand again, tighten the crank nut. It will cause the flywheel to turn, but it shouldn't affect the position of the flywheel on the filed key. The rope will act as a stop. Torque it down to around 26 ft/lbs.

 

[GypsyCliff]

You have to pull the flywheel and the key from the crank, file .025 off 1/2 the depth of the key on the Right side as you look at it (Base needs to stay the same so it fits in the key Way), then reinstall the flywheel correctly. Using a rope as a piston stop, put the flywheel and nut on over the crank with the key installed. Rotate the flywheel all the way counter clockwise using the flywheel to do so. Hold the flywheel counterclockwise with you hand only and snug down the nut. Then, without touching the flywheel with your hand again, tighten the crank nut. It will cause the flywheel to turn, but it shouldn't affect the position of the flywheel on the filed key. The rope will act as a stop. Torque it down to around 26 ft/lbs.

drf255,

OK, got it. Very good, precise explanation! I understand everything you said, which for me is saying something. Because I am almost learning disabled when it comes to having things explained to me. Sometimes people have to explain things to me Multiple times, especially directions. But I got your instructions right away!

Thanks tons.

Cliff

 

[GypsyCliff]

It would be of great help if you could post a pic of the muffler on your saw, as there are a few different muffler designs used on 028's.

The idea behind a muffler modification is to increase air flow. The first step in doing this is to remove the spark arrestor/catalytic converter. Check your local laws before removing the spark arrestor, as it's against the law in some parts of the world to operate a chainsaw without one.

After the spark arrestor and baffle are removed, reinstall the muffler, and retune the carburetor. If you are not happy with the saw's performance, you will have to increase the size of the opening on your muffler. Depending upon what style muffler your saw has, this can be done with something like a Dremel tool.

If you want to get fancy with your muffler mod, you can add either a second opening to the muffler, or add a short pipe to the current one. (Or both.)

Be careful not to over-mod the muffler, if you do, the saw will be way to loud to operate comfortably. I've read on this site that the surface area of muffler opening(s) should be about 85%-90% of the surface area of the exhaust port on your saw's engine. This will provide maximum performance while keeping the noise relatively low.

One way to measure the area of the engine exhaust port is with spaghetti, make sure the piston is at top-dead-center, and put spaghetti lengthways into the exhaust port until no more will fit. Count the noodles, subtract 10% and mod the muffler until the 90% of spaghetti will fit into the opening(s) of the muffler.

Hope this helps!

Pictures as asked for;



Don't know about anyone else, but I am AMAZED at how clean the inside of this muffler looks, considering that, as far as I know, it has NEVER BEEN OFF! Never been cleaned, or had Anything else done to it in over 30 years of cutting!

I've seen the interiors of of other mufflers that were clogged up, greasy, and extremely nasty looking. But not this one. No siree. As anyone can clearly see, this one looks practically Brand, Spanking New.

I have to assume that this means it has been running on almost a perfect mix.



Any comments would be more than welcomed. I'd like to know if my suppositions are correct, or if I'm deluding myself. And of course that leads back to the original purpose of this thread; modding the saw/muffler, and where do we go from here.

Funny how I never had any idea what the interior of the muffler looked like.

TIA.

Cliff

 

[happysaws]

Pictures as asked for;

View attachment 563905 View attachment 563928

Don't know about anyone else, but I am AMAZED at how clean the inside of this muffler looks, considering that, as far as I know, it has NEVER BEEN OFF! Never been cleaned, or had Anything else done to it in over 30 years of cutting!

I've seen the interiors of of other mufflers that were clogged up, greasy, and extremely nasty looking. But not this one. No siree. As anyone can clearly see, this one looks practically Brand, Spanking New.

I have to assume that this means it has been running on almost a perfect mix.

View attachment 563933

Any comments would be more than welcomed. I'd like to know if my suppositions are correct, or if I'm deluding myself. And of course that leads back to the original purpose of this thread; modding the saw/muffler, and where do we go from here.

Funny how I never had any idea what the interior of the muffler looked like.

TIA.

Cliff

I have never worked on an 028 with that style muffler, somebody else will have to chime in here...

 

[Duane(Pa)]

Do you have a Dremel? Cut that whole cage out. If not, drill a bunch of holes in that cage over the exhaust port. Do this with the muffler body completly removed so you can keep things clean. You will flow more air, and need to richen the carb screws to compensate. I would leave the cover the way it is (for now anyway) See what you think, before carving that up.

 

[GypsyCliff]

I really need a chip deflector/guard for this saw. Must be exactly like this:



I tried ordering one, but was sent the wrong one and it won't fit. I bet I've looked at 100 that were all wrong. Thanks for any help.

I posted this in the Tradin Post too, just in case you were wondering! I do not understand why this part is so extremely hard to find! I swear, a person could build this whole saw with bought parts and Still not be able to find this one part!

Cliff

 

[drf255]

Cut open the sides of the baffle but leave the front closed. That way the exhaust flows out the sides and not the front of the baffle.

Replace the screen in your muffler front with coarser screen. You can get stainless 'House Fabric" mesh at Home Depot.

The idea is to have some turbulence in the muffler so that the sound waves can cancel each other out. If you go straight out the front, the saw will be much louder but not any quicker.

I'm fine with noise from a saw. In fact, I like em loud. But I don't see the point of extra noise if there's no performance increase.

I avoid straight shots out the front of the can whenever possible. On saws with no internal muffler baffle, I will even weld the front opening closed and add a side deflector.

 

[Mad Professor]

I have never worked on an 028 with that style muffler, somebody else will have to chime in here...

Don't look like the 028 mufflers I have or what's on my IPL.

I would not remove the baffle on the inlet but would open up the holes for more flow.

The outlet will be tougher. All the stihl mufflers I've seen with the screen you could remove the screen by removing a screw, and enlarge the outlet while still retaining the screen and outlet baffle. Might see if you could find one of those outlet casings if you don't want to weld/braze.

The other 028 outlet casing just has a pipe inside that also serves as an outlet with no screen

 

[husky362]

I think I would cut out !/4 maybe a little more off the bottom so it flows more easy.. I agree that you don't want a strait opening out front

 

[Frogfarmer]

I wish I had one here for pics. I don't cut the inner because the holes are plenty big enough to flow adequate exhaust. The outer shell needs the louvers removed and opening enlarged. It will make a noticable difference. The outer shells are not available and difficult to find used to it's permanent once it's done.