Woods Porting

[JohnG28]

Ok, Im still a little new to some stuff regarding saws, and I have read about people woods porting saws. What exactly is woods porting?

[windthrown]

Woods porting may be any of a number of things. They typically include: opening up the muffler (by grinding, drilling, or adding factory port options), opening up the intake and exhaust ports (by grinding and polishing), lowering the jug by milling or using thin/no gasket to raise the compression (called squish), turning down the piston around the top edge to allow for more squish, and tuning, rejetting or replacing the carb to allow for a richer gas flow. More radical porting may also include modifying the transfer ports and/or changing the mechnical timing of any or all of the ports (by grinding and polishing). It may also include removing material from the piston to make it lighter and polishing the piston ports under the skirts. It may also include changing the coil out to a non-limited type if it had a coil RPM limiter. Typically woods ported saws have a higher WOT RPM (at the max of factory specs, or higher). Generally the woods port is a less radical version than race porting, as the woods port is done on a saw that is intended to be a work saw run all day in the woods.

[JohnG28]

Thanks for the info, i figured that it had something to do with mods to muffler, but had heard those mods referred to as just muffler mods, so I didnt know if there was something different that I was missing...sounds about like the equivalent to tuning a sports car to tweak out more performance, and many saws would be the woods equivalent of a sports car, thanks again for clearing that up for me

[Cut4fun]

To give you a idea, a comparison between a stock Jonsered 490 and a ported Partner 5000. Same type piston and cylinder is used on both saws. Now the 490 only has 325 stihl RS chain and the 5000 pulls 3/8 stihl RS.

Now be warned not all builders get the same gains out of there ported saws. BEWARE and check and choose your builders closely, you may not be getting what your paying for. Just because they are hyped up by others dont make them good builders. 

stock 490



ported 5000

[thumper]

other than my hyped up self  a cheap mic, all sorts of grinders and a basic idea of porting (maybe death of saw )  who actually does reputable cylinder work for work saws, at a good price? nobody in my area does this type of thing. they all think im wasting my time when i modify anything.

[Cut4fun]

nobody in my area does this type of thing. they all think im wasting my time when i modify anything.

I can't figure out what area your talking about without telling us. 

[thumper]

the great old northern maine..

[windthrown]

Seems that there are some good builders in the midwest, and a few out here in the west west. I have run some here from Dean and Jasha, and one DN saw. They all ran really good, but this was at some GTG events where people bring their good saws to.

As for bad porting, that can and does happen. Even from some of these builders. I have seen some not so well ported saws come on the market with some rather shady statments about performance. I also have to question when some guy wants to sell a woods ported 361, and will consider a trade for a stock 361. Makes you wonder why he wants a stock 361? Oops...

You need to treat the transfer ports with respect, and you can screw up the mechnical timing pretty bad if you mess up the ports. I have seen guys pull the jug gasket out of a saw (or thin it and put in a Bud can gasket) just trying to raise the compression of a low compression saw. They would have been far better served to replace the rings. I have also seen exhaust ports made too wide on Stihls that nearly clip the rings. I have also seen saws with gobs of low end torque, but they cannot cut for crap when WOT. Porting affects the torque and power curves, where they peak, and the response of the saw.

As for muffler mods in woods porting, that is typically done to help the ported saw move the gasses along better. Porting can be done in stages of complexity and stopped at any point, and some stages can be skipped:
1) muffler opened up and/or gutted and/or the CAT removed and carb re-tuned richer
2) cylinder ports opened up and polished
3) cylinder base turned down and the outside of the piston crown turned down
4) Transfer ports opened up and/or polished, piston lightened/polished
5) Carb rejetted or swapped out with a bigger carb
A non-limited coil can be added at any time.

Note also that some saws do not lend themselves to being woods ported. For example, the Stihl 1123 and 1127 line of saws. They have clamshell engines, and are nearly impossible to squish. So you can mod the muffler and widen and polish the ports, and retune the carb, and you are done. On my 310, I just opened up the muffler and re-tuned the carb. Easilly a 10% gain. Took all of an hour. On my 044 I added an 046 factory dual port muffler cover and retuned the carb. Similar results, but it only took 15 minutes. On my 066 I added a custom dual port cover, retuned the carb, and replaced the rev limiter coil. I got between a 15-20% gain from that one. On all of my 026s (five or six of them) I have done mild muffler mods to full port jobs. I am still messing with them trying to find the best setup.

[Al_Smith]

It's a lot of fun to twiddle and fiddle to soup up a saw . I've had pretty good luck at it myself but it's not for everybody .

You can't just carve away on them though without a plan of action or chances are the end results will be less than desirable . It does little good to have an engine that runs 15,000 RPMs but doesn't have power to push a pizz ants motor scooter .

[Rocky_J]

I've bought porting work from several builders over the years and have learned that nothing is guaranteed except inconsistency. I've had a couple exceptional saws, several duds and most have had modest gains but not as much as I expected. I guess the couple of exceptional saws have ruined me. Most of the builders I've dealt with (after following them on these forums) have horrible turnaround times. 6-8 weeks is average and sometimes your saw can disappear for several months, then you are the bad guy when you complain. I've weeded through a lot of saws (and builders) and finally have every saw in my arsenal ported and performing to my satisfaction. It hasn't been cheap or quick.

I have high hopes for the latest builder I've used. He did a very nice job on my 395xp last year and was thorough and prompt with it. I like the fact that he's a perfectionist. Unfortunately he's in Ontario, Canada so the shipping back and forth isn't cheap, and using UPS isn't an option due to Customs duties and taxes. But considering what my saws earn me over their lifetime, a few dollars shipping is nothing.

[JohnG28]

Thanks again for all the clarification guys, its appreciated, and thanks for the videos Cut4fun, they definately show the differences well

[bandmiller2]

You guys must be alot of man.I keep trying to outwork my 046 stihl and loose every time,it wants more wood I want a nap.I think the money spent for porting would be better spent on sharp files,only my opinion,old and grumpy.Frank C.

[bandmiller2]

Rethinking the porting thing I can see where a bucket jockey could use a ported saw where weight ,compact size and power are important.If you can cut a branch quick enough before it realizes its been cut it will fall straight down not swing on its hinge.Frank c.

[Al_Smith]

It's just neat to have a fast saw . In my case it's a challange to make it fast .

Some people like souped up cars, computers ,fast boats .For me getting the saws built is a much fun as operating them but then again I'm just a tad eccentric 

[Cut4fun]

A timber faller broke down how much more production he took in on a day when using his woods ported saws. Like he stated time is money.

[windthrown]

You guys must be alot of man.I keep trying to outwork my 046 stihl and loose every time,it wants more wood I want a nap.I think the money spent for porting would be better spent on sharp files,only my opinion,old and grumpy.Frank C.

Hmmmmmm. I could bog down my stock 460 falling 3 foot DBH trees. They are fairly easy to over-lever and bog with the dogs set in a buck or back cut. Even with a razor sharp chain. I added a DP muffler cover to my 044 with a light port mod and it easilly runs with the stock 460 now. A tad less weight and way less vibration than a 460. Easier to control, less tiring. I sold my 460. I don't need it, and the vibration killed me when I used it.

The 460 DP muffler cover for my 044 was $35 at Stihl. The labor to port my 044 was 'free'. Well, the tach cost me $85. But anyone would be well served in getting a good tachometer if they make a living off of their chainsaws. When they were stihl available, a new 440 with a DP cover was a lot cheaper than a new 460 as well. Money to buy lots of files with. 

440 vibration: 4.2/4.5 m/s*s ( measured left/right )
460 vibration: 4.2/6.0 m/s*s ( measured left/right )

440 weight: 13.9 lb. (full wrap like I have 14.8 lb.)
460 weight: 14.6 lb. (full wrap 15.2 lb)

[bandmiller2]

Windthrown,you must fall in the "lot of man" catigory,I've never cut west coast.Only know northeast trees.How does porting affect the longevity of a saw in the work envourment??If you used two identicle saw one wood ported outher not which would live longer?? thanks Frank C.

[Al_Smith]

Most people have pretty good luck as far as longevity of use from most "enhanced " saws . I suppose there are exceptions to that rule though .

Stop and think about it though .If all you did was reduce the back pressure on the muffler  and retuned the carb it first will run better and produce more power .In addition it will run cooler . It would make sense that alone would add to longevity of usage .

Fact is residing in my shed is my dads old saw he worked over some 30 years ago .That old Mac still cuts as good today as it did in 1980 .Actually better than it did factory fresh . Still starts on 4-5 pulls after sitting 6 months . Just one example but I'm sure there are more .

[Rocky_J]

But Al, changing anything on the saw will instantly void the warranty!!! 
Then it will die and I won't be able to do anything because the dealer will scold me for changing my own saw!!! 

 

[Al_Smith]

Well actually because of that my tree trimmer bud left his new ones stock for the 30 day warranty period Stihl puts on their pro saws . I imagine come about spring time he'll want a little enhancement done because compaired to mine his new ones are dogs . He's complained since he bought them as replacements for ones that were stolen .

That doesn't make sense, newer but slower.What's wrong with this picture 

[Rocky_J]

But it is safer to run the saws with catalytic mufflers and ultra lean carb settings so there's no extra pollutants in the exhaust. All those things make the saw last longer! The government wouldn't do anything to make our saws burn up. They mandated ethanol, which protects our saw motors as well. Everything on the saw is there for the sole purpose of making the saw as powerful and as durable as possible. None of the government mandates will ever cost us a single minute of motor longevity. It's best to leave the saw 100% stock the way the government dictates it should be, because the government is so efficient and knows what is best for us.

All those mods that people talk about doing must hurt the saw, people are not as smart as the government.

[bandmiller2]

This subject has been flailed into submission but why wouldn't manufacturers make some of these minor improvements and call it factory porting or would the EPA get em.Frank C.

[Rocky_J]

They are not allowed. Fortunately, the EPA doesn't come into my garage and smog check my chainsaws. But new saws must meet set standards.

[stonebroke]

But it is safer to run the saws with catalytic mufflers and ultra lean carb settings so there's no extra pollutants in the exhaust. All those things make the saw last longer! The government wouldn't do anything to make our saws burn up. They mandated ethanol, which protects our saw motors as well. Everything on the saw is there for the sole purpose of making the saw as powerful and as durable as possible. None of the government mandates will ever cost us a single minute of motor longevity. It's best to leave the saw 100% stock the way the government dictates it should be, because the government is so efficient and knows what is best for us.

All those mods that people talk about doing must hurt the saw, people are not as smart as the government.

Are you sure you don't work for the Obama administration

Stonebroke

[Cut4fun]

Well actually because of that my tree trimmer bud left his new ones stock for the 30 day warranty period Stihl puts on their pro saws . I imagine come about spring time he'll want a little enhancement done because compaired to mine his new ones are dogs . He's complained since he bought them as replacements for ones that were stolen .

That doesn't make sense, newer but slower.What's wrong with this picture 

Al did he get a new MS660 to replace that fine 066 he had and you brought to that one GTG?

If so look at that pencil eraser size outlet hole on the new 660. No wonder they cant get out of their way now days and are pigs new, they cant breath.

[Al_Smith]

Yes he did and as a matter of fact it is residing in my shed at the moment to prevent further theft .Sad to say that new one is a dog ,very discouraging for the one model of saw that pretty much has set the standards whereby most saws are judged by .

I kid you not I can out cut that thing with my 038 Mag ,sad indeed .

Actually unless it's something that requires the full use of the 36" bar on the Stihl he has been using a 281 Husky which will cut circles around that new 660 . The Husky is bone stock and 20 years old to boot .

That's what they've done to our saws ladies and gents .

[Cut4fun]

Al your going to open that muffler up for him on the stock outlet aren't you  and tell him to put a DP cover on it for $50 stihl cost or make one using the stock cover like I do on the 084 cover.
Check that cage in that new 660 inner muffler. I bet it is pretty restrictive to now days.

[Al_Smith]

Yes I'll work it over for him when he says to . Usually on an 066 model all it takes is a little muffler work as they do pretty darn good even as a stocker .I imagine that muffler work would suit him just fine as far as any enhancement goes .

You know for most people just a little muffler tweak is all they ever want  because it does wake up the saw quite a bit .Besides that it is in essence free  if you do it yourself .

Like say a 200T .It's pretty much standard proceedure to jettison the screens on them by just about any pro user I've ever seen .The only people who don't are on the forums saying you shouldn't . In the real world it's much different .

[bandmiller2]

Its sad what their doing to the new saws to save squat.Its safe to say I'll never be buying anouther new saw,got about 10 good saws if I live long enough to wear them out I'll be filling my depends with sawdust.Frank C.

[Screaming Detroit]

Seems that there are some good builders in the midwest, and a few out here in the west west. I have run some here from Dean and Jasha, and one DN saw. They all ran really good, but this was at some GTG events where people bring their good saws to.

As for bad porting, that can and does happen. Even from some of these builders. I have seen some not so well ported saws come on the market with some rather shady statments about performance. I also have to question when some guy wants to sell a woods ported 361, and will consider a trade for a stock 361. Makes you wonder why he wants a stock 361? Oops...

You need to treat the transfer ports with respect, and you can screw up the mechnical timing pretty bad if you mess up the ports. I have seen guys pull the jug gasket out of a saw (or thin it and put in a Bud can gasket) just trying to raise the compression of a low compression saw. They would have been far better served to replace the rings. I have also seen exhaust ports made too wide on Stihls that nearly clip the rings. I have also seen saws with gobs of low end torque, but they cannot cut for crap when WOT. Porting affects the torque and power curves, where they peak, and the response of the saw.

As for muffler mods in woods porting, that is typically done to help the ported saw move the gasses along better. Porting can be done in stages of complexity and stopped at any point, and some stages can be skipped:
1) muffler opened up and/or gutted and/or the CAT removed and carb re-tuned richer
2) cylinder ports opened up and polished
3) cylinder base turned down and the outside of the piston crown turned down
4) Transfer ports opened up and/or polished, piston lightened/polished
5) Carb rejetted or swapped out with a bigger carb
A non-limited coil can be added at any time.

Note also that some saws do not lend themselves to being woods ported. For example, the Stihl 1123 and 1127 line of saws. They have clamshell engines, and are nearly impossible to squish. So you can mod the muffler and widen and polish the ports, and retune the carb, and you are done. On my 310, I just opened up the muffler and re-tuned the carb. Easilly a 10% gain. Took all of an hour. On my 044 I added an 046 factory dual port muffler cover and retuned the carb. Similar results, but it only took 15 minutes. On my 066 I added a custom dual port cover, retuned the carb, and replaced the rev limiter coil. I got between a 15-20% gain from that one. On all of my 026s (five or six of them) I have done mild muffler mods to full port jobs. I am still messing with them trying to find the best setup.

In stage three you said turn down the out side of the piston, how much and is this so it inhales and exhales better?

[Al_Smith]

       In stage three you said turn down the out side of the piston, how much and is this so it inhales and exhales better?

Those so called "Stages " are just terminoligy a few saw engine builders dreamed up.

The reason for a pop up piston is several fold .If you cut a pop up it maintains the compression better ,causes the flame front to spread better and in essense raises the exhaust port without exposing a lot of piston to the exhaust which has a tendency to burn the piston .

Not everyone does it and still have really good running saws .It's just one method to enhance performance .

How much of a pop up depends on who is doing it I suppose .I have an 038 mag with a 30 thou pop up and a 200T with 12-15 thou . I've seen as high as 40 or so thou on saws done by others .There may be higher than that but none I've ever personally seen .

[windthrown]

Windthrown,you must fall in the "lot of man" catigory,I've never cut west coast.Only know northeast trees.How does porting affect the longevity of a saw in the work envourment??If you used two identicle saw one wood ported outher not which would live longer?? thanks Frank C.

Well, I do not fall trees with my willie.

"Woods" porting as it is called is targeted to modifying a daily runner, so the porting is less aggressive/lighter than for a race saw. If they are done right, a woods port can enhance the life if a chainsaw. They will run cooler and breathe better and have more power. If they are done wrong, they can create a less lively saw. For these reasons I generally leave the transfers alone and leave the mechanical timing set to stock or near stock values. I do light port grinding for better engine breathing, shave the jug down just a smidge, open up the muffler to original stock design or a bit more, and tune the carb richer. Also note that in most cases a modified saw will not gain any value on the market. As stated, porting will void the warantee, and in many cases builders create some odd-ball saws that just do not have the power that would be desired from a ported saw. However, when they are done right, the ported saws have better power, better response, they run cooler, and in many cases they will outlast their stock cousins becasue they do not run as lean. Lean saws run hot, and running hot can lead to engine scoring, typically on the cylinder wall below the exhaust port where the most heat builds up. 

As for why companies do not port their own saws, it is the result of US EPA laws. In many cases they do make more open saws, but they are not for sale in the US. For example, the European Stihl 361 and 290/310/390 saws have better (more open) mufflers and richer carb settings. In many cases they originally made and sold more opened up saws in the US and they have become choked up over the years due to Federal EPA (and California state) regulations. The Stihl 026/260 is a good example of this. The early model 026 mufflers had more or larger ports in them, and the carbs were fully tunable. Now they have choked up mufflers and smaller ports, internal baffles, and they have limiter caps on the carbs to keep them from being richened up. By law no dealer can modify a chainsaw or face stiff penalties from the EPA. The EPA sent out flyers and notices to all chainsaw and small engine dealers late last year warning about doing any modifications. Owners are not restricted or limited by these laws though.

[windthrown]

In stage three you said turn down the out side of the piston, how much and is this so it inhales and exhales better?

The main reason to turn down the piston crown is not for better gas flow from an intake to exhaust gas flow perspective (in some cases it actually screws it up *see below). Nor would you turn down the piston alone. That would lower the compression and make the squish larger (both bad from a performance standpoint). The main reason that pistons are turned down is for increasing engine compression when done in combination with turning down the cylinder. Higher compression will usually result in more power. To increase compression, most builders turn down the base of the jug. You can also remove the base gasket, or use a thinner gasket to get the same effect. Turning down the jug a lot or using a no gasket may casue a problem in that the outer crown of the piston will hit the top of the cylinder at TDC in the outer squish area. To prevent this from happening, the outer rim of the piston crown is turned down which domes up the piston crown center and prevents the piston from coming into contact with the cylinder head at TDC. The second reason that pistons are turned is to get a thinner squish band area. This has to do with the combustion chamber and piston crown shape. The gasses are pushed out of the squish area from the outside of the cylinder/piston just before TDC toward the dome area of the cylinder 'head'. This causes good movement and mixing of the fuel, prevents dead space and pockets of exhaust gas from forming, prevents uneven burning of the fuel, and helps to prevent pre-ignition. These are all good things.

There are several 'rules of thumb' regarding the limits to take the squish. The squish is measured at the outer edge of the piston at TDC. Typically you measure the squish by poking a thick solid solder wire bent at the tip into the spark plug port and push it in to touch the side of the cylinder wall with the piston below TDC. Then pull the piston up to TDC and back down, and then remove the solder wire and measure the thickness of the squshed end. A stock saw might have a squish of 0.035-0.04". Typically a woods ported saw would have a squish somewhere around 0.02", and a race saw might have as little as 0.01" squish. The stock and building recipies vary a lot in terms of squish. The piston turning limit is that you do not want to turn the piston down into the top ring slot, and you need to leave a gap (minimum 0.1") between the crown and the top ring slot.  

* Note that turning the piston and cylinder base down both change port/mechanical timing of the intake, exhaust and transfer ports. They also counter each other; lowering the jug directly lowers the ports, and lowering the piston crown in effect raises the ports back up. Typically squish is decreased on a ported saw, so the net effect is that the ports are lowered. Note also that you can increase the squish by turning down the cylinder without turning down the piston. But in this case, you are lowering the ports.

[John Mc]

Windthrown,you must fall in the "lot of man" catigory,I've never cut west coast.Only know northeast trees.

Remember, Windthrown mentioned he is bogging it in 3 ft DBH trees. probably not too many of them in your neck of the woods, are there, Bandmiller.

[bandmiller2]

John,there are more than you think,just yesterday I was walking in my neighbors woodlot many ewp in that 36" catigory wether their solid to the core I don't know.Most of the logs I get are from a tree service and come off old estates and yards some are real lunkers but I don't like working with them,16" to 18" is what i like.Frank C.

[JohnG28]

Well I got a chance yesterday to see a fully done saw, stihl 046, ported, squished, mm, in action, and I can definately understand now why someone would mod their saw, that thing ate the tree like nothing, when my warranty is up on my saw I may look into some light mods, and thanks to forum member mark for the demo and look at your operation, appreciate all the info...thanks to all of you as well for all the details and great explinations of everything

[Mark K]

Glad to have you stop by. Let me know if you want that 361 done. I'm thinking about having my newest 385 done. I'm trying to contact the builder that did the 046. Feel free to stop in anytime.

[Rocky_J]

Here's a video from today of my seven year old ported Husky 346 (46cc). I've never been inside the motor since it was ported and it gets run a lot.

[JohnG28]

Nice Rocky, looks like youve got quite a ripper there

[Rocky_J]

I've had four other 346's built for me by three builders and none have come close to matching this one. I have another one on order with yet another builder right now, which was why I made the video. The saw wasn't prepped at all for that clip and hadn't been serviced in over a week. And probably 30 minutes cutting time since the last chain sharpening. I don't race saws, I just work them.

[VTLogSlayer]

Im interested in doing a few of the smaller, cheaper things to my 044.  I like the idea of the dual port muffler from an ms-460.  other then that does anyone have any ideas on builders that would work on my ol' girl? if i had the tools i would do it myself. but being in school doesnt help out the whole equation.  thanks,
KG

[windthrown]

DP muffler is the easy to do mod. For the 044 its a factory bolt on cover and then re-tach your carb. Done. That is about the best that you can do w/o tools and some knowledge about 2-stroke engines and working with metals and precise measuring. You can clean up the piston and exhaust port and get all the carbon out of there as well. Nothing much to that, and it will help.

The next level of minimal tool work is if your compression is low (below 150#). I would recommend a set of new rings. You can put them on pretty easy, but it can be tedious. You will also need a new cylinder gasket. You can shave the cylinder base down with fine emery paper on a piece of glass to take the original gasket gunk off. You can also take 0.005" off the base while you are at it and not have to turn the piston down any. But you need to measure the squish before and after to verify your work. And you need a steady hand to remove the base of the cylinder down evenly. Both of these items (rings and cylinder shaving) will increase your compression, and that will result in more power and better response, w/o changing the timing.

The next level requires more tools, planning and knowledge. Porting, window and polising work will require a Dremel or high speed type drill, stones and bits, and some idea of what you are doing. You also want to know your original port timing and compensate for changes. I recommend that if you are not experienced in this, get some scored cylinders and pistons and grind, campher and polish them to see how it is done. If you mess up a scored jug, no big deal. It will just make for a more interesting ash tray. If you mess up a good Stihl or Mahale cylinder, that can cost you a couple hundred dollars to replace. Also when you begin porting, do a mild port to start with. Do not go hog wild and open everything up to the limit on your first try. That will tend to change the torque curve and the response of the saw, and it can run worse as a result.

More radical porting stuff requires more expensive tools. Turning the piston and cylinder down requires a good metal lathe setup, as well as a micrometer and solder, and a really really good idea of what you are trying to do. Measurements needs to be precise and cutting needs to be exact. You also need to compensate for timing changes due to porting, cylinder and piston height, and calculate and compensate for changes in your transfers and window ports. You also need to consider the size of the carb, and the jets used in them, as well as the coil and any other limitations that it might have. You also have to factor for faster revs, and consider upgrading other parts on the saw becasue it will have more power and torque (if it is done right).

[VTLogSlayer]

Wow guess i should learn to to do that stuff.  So what are your thoughts about a new complete DP muffler?? or is the DP cover alone gonna do the job? another question  if i were to buy a dremel would it possiable for myself to do some shaving? or am i going to ruin my saw 

[Al_Smith]

On this subject on porting and certain stages or degrees of same ,I'm going to do exactly that .

I have a Stihl 034 with an 036 cylinder .Of which I will get some times as is in a somewhat stock condition . Afterwards I plan on doing a type of modification that could be done by nearly anyone with just basic tools and no machine work .

Lastly the plan is a full out mod with a shaved piston ,turned down base and reworked ports . I think that just a basic mod with some muffler work will surprise most people who have only been exposed to bone stock factory tuned   saws .

[windthrown]

Wow guess i should learn to to do that stuff.  So what are your thoughts about a new complete DP muffler?? or is the DP cover alone gonna do the job? another question  if i were to buy a dremel would it possiable for myself to do some shaving? or am i going to ruin my saw 

On the 044/440 or 046/460, and 066/660 all you really need are the DP muffler covers. They have 4 holes on them to screw the facotry torx bolts into and they are an exact fit. The DP cover replaces the stock flat cover. On the 044/440 and 046/460 the same 460 cover fits both. The 066/660 DP cover is different. 

I would highly recommned that you Dremel a scored jug before you run it on a good one to get the feel of it. Different bits and stones work differently in the soft alloy saw metal, and aluminum alloy is easy to screw up with steel bits and stones. Some stones are made for steel, and they load up with soft aluminum as well. Some bits are hard to get in there, especially when camphoring. Also you need to figure out how to map what you are going to grind away before you start grinding. Some people can do it free style and in their head, some people draw on the jug to mark where to grind. It is a skill and an art.

[windthrown]

On this subject on porting and certain stages or degrees of same ,I'm going to do exactly that .

I have a Stihl 034 with an 036 cylinder .Of which I will get some times as is in a somewhat stock condition . Afterwards I plan on doing a type of modification that could be done by nearly anyone with just basic tools and no machine work .

Lastly the plan is a full out mod with a shaved piston ,turned down base and reworked ports . I think that just a basic mod with some muffler work will surprise most people who have only been exposed to bone stock factory tuned   saws .

036s are good saws to mod and they respond well to them. As are 026s. I did the several steps mods on a series of 026s that I have, but I never photographed any of the port mods. I do not have a macro lens on a camera that takes good close up photos. I also never did a pop-up tunred piston. I wrote a piece on stock and modified 026 mufflers on another forum, but that was it.

[Al_Smith]

Oh it wouldn't make any difference if you gave port timing numbers ,took pictures or gave detailed instructions .No two people will have the same results .Those that run lousey would complain you gave them false info  any way .

It's not hard to get results it's just that some get better results .

[VTLogSlayer]

Thanks for all of the great info windthrown! Spring break is next week, gonna be makin some money, gonna try and get the DP muffler.  cant wait to start doing some of the things you mentioned, probably this summer ill tear it apart. 

[timber tramp]

  VTLogSlayer- I've also been thinking of adding a dual port muffler to one of my 044's, also a max flow air filter kit from Bailey's. If you get to yours before i get to mine, please let me know how you like it.          Thanks, TT

[VTLogSlayer]

TT, Yeah i would like to order it early this week. the max flow air filter looks like it would be a benefit as well. never thought of that.

[windthrown]

I have the HD stock air filter on my 044. It runs fine. The DP muffler added a good bit of power to my 044. Well worth the $35 I paid for for it. Cheap as chips compared to some of the spendy aftermarket stuff out there. Also if you want a larger second port, all it takes is a flat file on that 046 DP muffler cover. Note that the base of the 046/460 muffler will get in the way of an 044/440. The muffler covers are the same though.

440/460, 044/046 dual port cover Stihl PN: 1128 140 0801
660/066 dual cover Stihl PN: 1122 140 0800
044 serial numbers X29583701 or below have the 10mm wrist pins, the rest have 12mm wrist pins

[timber tramp]

  The max flow air filter kit claims to increase air flow from 89cfm to 135cfm. I figure if that's true, that along with an easier breathing exhaust, it should increase the saws output quite a bit. If I'm off base here please let me know.      TT

[JohnG28]

If theyre numers are true then that would seem to make sense to me.

[windthrown]

  The max flow air filter kit claims to increase air flow from 89cfm to 135cfm. I figure if that's true, that along with an easier breathing exhaust, it should increase the saws output quite a bit. If I'm off base here please let me know.      TT

If that is the case, that AF leans out the saw. More air = leaner running = hotter engine = scoring. If you do not richen up the carb, you will burn up the saw. Not saying that better air flow or the AF is a bad thing, but it can lead to bad things happening if you do not re-tune the carb. However one word of caution about thin air filters; they can let more crap into the engine. I have seen that on some off-road vehicles that let too much dust into the engine and they get damaged. Fine sawdust seems to burn OK. But 'regular' old dust is something that you do not want in there. The same can be said for opening up the muffler. After a muffler mod, you have to retune the carb. Actually it took a lot of dialing out the H screw after I added my DP muffler cover on my 044. That thing wanted to scream lean (plug was white). Make sure that they burple/4-stroke at WOT unloaded after any modification to the air flow.

Now after all this talk I have to go play with my 044... I realized that I have a better air cleaner from my DOA 066 that will fit on there. Not that my 044 seems to lack any power. But... it might have a few specs of carbon build up as well. Then of course I may have to take it apart again and open up the ports just a tad more. There is a good thread going on another forum where a guy stripped down an 044 and ported it for another guy up in Canada. Good photos of intake and exhaust porting, and piston window dressing.

[Red 93 L1 #3383]

660/066 dual cover Stihl PN: 1122 140 0800

Does the 064AV use the same daul port cover as the 066?  If not anyone have the correct number.

[Al_Smith]

Just put another hole in the one you have  already . The IPL for that saw lists about three of the covers but Stihl is rather vague the way they list things so it's hard to know exactly what is what .Clear as mud .

[windthrown]

660/066 dual cover Stihl PN: 1122 140 0800

Does the 064AV use the same daul port cover as the 066?  If not anyone have the correct number.

I dunno. I do not have an IPL for the 064, only the 066 and 660.