Muffler modding a chainsaw?
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CobraChevelle
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I am looking into buying a makita 64cc saw and I read on those the muffler is a 2 piece setup and you pull it apart and remove the converter they call it.. not 100% sure so don't take my word for it. I havent done alot of research yet. I also think they do somekind of porting too, but once again not 100% sure.. Just a quick look @ some of those forums
I am looking into buying a makita 64cc saw and I read on those the muffler is a 2 piece setup and you pull it apart and remove the converter they call it.. not 100% sure so don't take my word for it. I havent done alot of research yet. I also think they do somekind of porting too, but once again not 100% sure.. Just a quick look @ some of those forums
vintage nut
Well-known member
Echos are more of a pain. I do all the saw repair for the tree service I work at, since our dealer closed down.
For an echo I usually grind off the seam where the two halves are crimped together, pull out the cat, and tig or oxy acetylene weld the halves back together. If you aren't able to weld, you can also use a cordless drill, and drill through the cat from the opening. This isn't as good, but works pretty well.
Careful, its very easy to end up with 10+ chainsaws once you start working on one. I think I had over 17 at one point, but I have sold off a few.
you can never have too many tools
For an echo I usually grind off the seam where the two halves are crimped together, pull out the cat, and tig or oxy acetylene weld the halves back together. If you aren't able to weld, you can also use a cordless drill, and drill through the cat from the opening. This isn't as good, but works pretty well.
Careful, its very easy to end up with 10+ chainsaws once you start working on one. I think I had over 17 at one point, but I have sold off a few.
you can never have too many tools
vintage nut
Well-known member
Porting is a whole nother thing, that I'm still in the process of learning. Currently porting and rebuilding a stihl ms440 for my boss. It's far more complicated than a muffler mod, but can give you far more power.
you can never have too many tools
you can never have too many tools
zak77
Well-known member
I did a muffler mod to my Husky 350 by adding an additional exit port on the stock muffler. I think it gave it a little more power but I cant say for certain. There are a number of things you can do to increase power by eliminating the base gasket on the cylinder, porting/polishing, high compression pistons, etc. I don't use my saw professionally so when I do use it I know it's limitations so I wasn't expecting to turn a stock saw into a full-bore ripper by opening the muffler up a tad.
I took the muffler off and looked it over closely to see if there were things I could improve upon but to my luck, there wasn't anything in the muffler that'd restrict flow but the exhaust port did seem small. So I drilled 2 1/2" holes in the side of the muffler and welded on a small deflector to push the exhaust outward. Then I adjusted the air/fuel mixture to match and it sure is a little louder but cant say for certain it gained more power or torque. One complaint I heard about the 350's was the heat from the muffler will melt the plastic housing, and it was starting to happen so hopefully the more open muffler will remove some of the heat and keep it cooler.
I took the muffler off and looked it over closely to see if there were things I could improve upon but to my luck, there wasn't anything in the muffler that'd restrict flow but the exhaust port did seem small. So I drilled 2 1/2" holes in the side of the muffler and welded on a small deflector to push the exhaust outward. Then I adjusted the air/fuel mixture to match and it sure is a little louder but cant say for certain it gained more power or torque. One complaint I heard about the 350's was the heat from the muffler will melt the plastic housing, and it was starting to happen so hopefully the more open muffler will remove some of the heat and keep it cooler.
Opening them up can give a pretty considerable bump in power, up to 20% on some saws.
If your muffler has a catalytic converter in it, gut that sucker. It creates a lot of unnecessary heat that can shorter the life of the saw.
Otherwise you're just enlarging baffles and outlets to allow a little more flow.
If your muffler has a catalytic converter in it, gut that sucker. It creates a lot of unnecessary heat that can shorter the life of the saw.
Otherwise you're just enlarging baffles and outlets to allow a little more flow.
Milton Shaw
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Its not been mentioned to remove the spark screen from the muffler would be the first thing that should be done. Most chain saws, blowers etc have that screen to meet government rules to keep from setting forest fires. They clog up to the point that the motor won't rev up above idle speed.
pauls_workshop
Well-known member
Couple things. If you port the muffler or anything, you will void the mfr warranty. If you remove the spark screen, then it is illegal to run your saw in a public place, as fires are more possible. Of course, you could always put it back in if you ran it there for a job. I've ported the muffler on my little 42 cc Craftsman/Poulan and got about 20% or so more power out of it. Really transforms that saw (and many saws). Note, if you do this, almost certainly you must adjust the carb settings, as you'll need to run the fuel more rich than before. Never run a saw lean as you will destroy them fast that way. - Paul
When you buy a new chainsaw you are buying a kit. The first thing to do is open up the muffler so the saw runs more efficient and cooler. The mufflers outlet should be sized about 75% of the exhaust port size. Dual porting the muffler helps accomplish this. Make sure you use spark arresters..
The second thing is to tune it up so it's runs richer. They often come way too lean from the factory.
The third thing is to throw away the safety chain and replace it with chain designed to cut.
The EPA doesn't care if your saw dies due to lean seize and OSHA doesn't care if it cuts.
After that you can dive into the word of porting and timing.
Here are some examples of my dual port muffler mods (Makita DCS6401 and Stihl MS361):
Thanks so far guys. I'm glad. A remove the muffler and go to town soon. How does one adjust these things? I'm not very good with small 2 strokes. I know there is a high and low but how and where do you adjust the settings too?
For the H and L screws, CCW=more fuel. The other screw is just the idle speed, and CW=faster.
I'm not a carb expert but you might enjoy my version, it's very KISS
adjust the low richer if you pull the throttle and it doesn't rev up smooth. give it a little more past the point where you eliminate the bogging down and it should be rich enough to stay happy in different weather. I go 1/8 turn extra.
Adjust the high richer if you feel like the top end power in the middle of a cut isn't as much as it was at the start. I only do this after sharpening the chain just to make sure it's not giving you a false failure.
The idle should be pretty straightforward. For Husq and the ones it owns, factory is 2-1/4 turns out from the tightest so if you screw it up you can zero it out and try again.
pauls_workshop
Well-known member
When you buy a new chainsaw you are buying a kit. The first thing to do is open up the muffler so the saw runs more efficient and cooler. The mufflers outlet should be sized about 75% of the exhaust port size. Dual porting the muffler helps accomplish this. Make sure you use spark arresters..
The second thing is to tune it up so it's runs richer. They often come way too lean from the factory.
The third thing is to throw away the safety chain and replace it with chain designed to cut.
The EPA doesn't care if your saw dies due to lean seize and OSHA doesn't care if it cuts.
After that you can dive into the word of porting and timing.
Here are some examples of my dual port muffler mods (Makita DCS6401 and Stihl MS361):
That is some super nice work there! Mine don't look like that! - Paul
vintage nut
Well-known member
The key to tuning the high side is that it should 4 stroke (run rich enough to missfire) at wot until its in the cut. Hard to explain but very easy to recognize once you hear it
you can never have too many tools
you can never have too many tools
Thanks for all the info. Im probably going to go at it this weekend if I have time.
Right now it fires up but has a slight bog if you nail the throttle, my buddys husky 455 doesnt do it so it likely needs a small adjustment. Im gonna work on getting the muffler apart and take it from there.
Right now it fires up but has a slight bog if you nail the throttle, my buddys husky 455 doesnt do it so it likely needs a small adjustment. Im gonna work on getting the muffler apart and take it from there.
Give the L jet a bit of a turn CCW and I bet it'll clear up. You'll have to adjust it periodically, depending on humidity and temperature.
Well yesterday it had a slight off idle bog. Hit the throttle and it didnt rev up asap. Now it does..
I figured wtf I have some free time now and just spent an hour cleaning it up, and fixing the cracked casing with the horrible freight cheapo plastic welder (worked well too lol).
I then took the muffler off, it would appear its pressed together, I didnt see any welds. I located the H/L adjustments just incase too. I examined the muffler and it appears the one end goes into a cat type converter with honeycomb/filter on the engine side, the outlet had of course that cheapy spark arrestor which I removed. I noticed it had a rather restrictive looking plate under that cover. 1/2 drill and 2 holes then a jig saw for good measure. Fired it up, yesterday was about 50-55F when I ran it, today its now 45F and the bogs GONE. I think it was a tad rich maybe and of course removing the restriction got rid of that.
Also it has a .325 chain, Im not sure the difference between a safety chain so IDK if its one or not but my buddy sharpened it for me anyways yesterday with his HF electric sharpener.
For 200 bucks this is one CLEAN saw, Im shocked they took so little for it. Place also had 2 pro huskys, the model numbers were long gone but they were def the old pro saws. I didnt want either b/c of the price but also b/c the one looked like a 36" bar (maybe 32"?) and the other was a 24" bar. Im thinking some crackhead stole them or a landscaper needed cash asap. They wanted $500 for the very large husky.
I figured wtf I have some free time now and just spent an hour cleaning it up, and fixing the cracked casing with the horrible freight cheapo plastic welder (worked well too lol).
I then took the muffler off, it would appear its pressed together, I didnt see any welds. I located the H/L adjustments just incase too. I examined the muffler and it appears the one end goes into a cat type converter with honeycomb/filter on the engine side, the outlet had of course that cheapy spark arrestor which I removed. I noticed it had a rather restrictive looking plate under that cover. 1/2 drill and 2 holes then a jig saw for good measure. Fired it up, yesterday was about 50-55F when I ran it, today its now 45F and the bogs GONE. I think it was a tad rich maybe and of course removing the restriction got rid of that.
Also it has a .325 chain, Im not sure the difference between a safety chain so IDK if its one or not but my buddy sharpened it for me anyways yesterday with his HF electric sharpener.
For 200 bucks this is one CLEAN saw, Im shocked they took so little for it. Place also had 2 pro huskys, the model numbers were long gone but they were def the old pro saws. I didnt want either b/c of the price but also b/c the one looked like a 36" bar (maybe 32"?) and the other was a 24" bar. Im thinking some crackhead stole them or a landscaper needed cash asap. They wanted $500 for the very large husky.
safety chain is low kickback. Likely your Echo came from HD originally but even if it was from a dealer, it likely has safety chain on it unless a pro used it and put on chisel chain.
If you don't live in a cabin in the woods safety chain is fine. IMO only pros need chisel chain, though plenty of guys think you aren't manly enough if you don't use it. Whatever.
Honestly, I would get a round file the right size for your chain and do it the old fashion way. I have one of those HF chain sharpeners but I think the hand file does a better job. You can get dremel bits that are the right size and do it that way, that's also better than the HF chop grinder. Amazon sells some that are diamond dust which are better than stone but even the stone ones are going to give you a round cut which is what the chain teeth really need. You can get that with the chop style but it's not as quick & easy as a round file.
If you don't live in a cabin in the woods safety chain is fine. IMO only pros need chisel chain, though plenty of guys think you aren't manly enough if you don't use it. Whatever.
Honestly, I would get a round file the right size for your chain and do it the old fashion way. I have one of those HF chain sharpeners but I think the hand file does a better job. You can get dremel bits that are the right size and do it that way, that's also better than the HF chop grinder. Amazon sells some that are diamond dust which are better than stone but even the stone ones are going to give you a round cut which is what the chain teeth really need. You can get that with the chop style but it's not as quick & easy as a round file.
Yea I looked at some pics online, its not a safety chain. Im a fan of whatever my buddy who sharpened it uses on his saws-they cut very well. I think they are non safety full chisel chains.
In all honesty this saw should do anything I want it to really. Its a bit better than your homeowner **** but not quite pro. But then again I was looking to buy a husky 455 rancher or similar stihl so its about on par. This one is from a dealer, name is on a sticker right on it. I know the dealers usually will tune whatever it is for you for optimal performance vs just grabbing stuff off the shelf at the home center.
I have the files already, the HF was just a quickie clean up job. What I really need is the tool kit as it makes life much easier.
In all honesty this saw should do anything I want it to really. Its a bit better than your homeowner **** but not quite pro. But then again I was looking to buy a husky 455 rancher or similar stihl so its about on par. This one is from a dealer, name is on a sticker right on it. I know the dealers usually will tune whatever it is for you for optimal performance vs just grabbing stuff off the shelf at the home center.
I have the files already, the HF was just a quickie clean up job. What I really need is the tool kit as it makes life much easier.
justme-
Well-known member
first I have to say chainsaws require more maintenance than most other tools - removing the spark screen is a poor choice - check it regularly and clean it (burn the carbon off with a propane torch) as part of your tune up.
Be careful opening up mufflers - yes cats create heat and resistance, but as mentioned 2 strokes need back pressure to operate properly - remove too much restriction from the muffler and you loose performance and efficiency.
if you heed 1 thing from this - make it this+ don't just richen the carb because someone told you so. If you want to tune it learn how and more importantly WHY. Too lean and you get a lean fault (not enough oil/fuel) however with today's lean running engines and epa regs carb passages are much smaller than 10 or 20 years ago and tuning too rich will potentially cause a rich lean fault...oil molecules are larger than gas molecules and can block flow or "filter" themselves out of the gas in the carb passages if run too rich. If you can see oil smoke in your saw odds are it's doing damage. Too rich also causes carbon build up in the cylinder that can lead to a whole host of other mechanical failures.
90% of carbs the low needle starts at 1 turn out and the high speed starts from 3/4 to 1 turn. Forget about the "T" screw - the idle speed. It's common to set the idle speed up high to get a finicky carb low speed mix in a range that will let the engine run then set it down. 90% of the time as long as the clutch is disengaged at idle the idle speed screw setting is done... the # of turns doesn't matter.
The "Safety" chain is good enough for 95% of saw owners. The only difference in low kickback chain is it's extra "hump" which only has an affect at the tip...and it's been tested even tho lots of guys "feel" a difference. Unless you're doing plunge cuts a lot there's no need for any other chain.
Be careful opening up mufflers - yes cats create heat and resistance, but as mentioned 2 strokes need back pressure to operate properly - remove too much restriction from the muffler and you loose performance and efficiency.
if you heed 1 thing from this - make it this+ don't just richen the carb because someone told you so. If you want to tune it learn how and more importantly WHY. Too lean and you get a lean fault (not enough oil/fuel) however with today's lean running engines and epa regs carb passages are much smaller than 10 or 20 years ago and tuning too rich will potentially cause a rich lean fault...oil molecules are larger than gas molecules and can block flow or "filter" themselves out of the gas in the carb passages if run too rich. If you can see oil smoke in your saw odds are it's doing damage. Too rich also causes carbon build up in the cylinder that can lead to a whole host of other mechanical failures.
90% of carbs the low needle starts at 1 turn out and the high speed starts from 3/4 to 1 turn. Forget about the "T" screw - the idle speed. It's common to set the idle speed up high to get a finicky carb low speed mix in a range that will let the engine run then set it down. 90% of the time as long as the clutch is disengaged at idle the idle speed screw setting is done... the # of turns doesn't matter.
The "Safety" chain is good enough for 95% of saw owners. The only difference in low kickback chain is it's extra "hump" which only has an affect at the tip...and it's been tested even tho lots of guys "feel" a difference. Unless you're doing plunge cuts a lot there's no need for any other chain.
vintage nut
Well-known member
I can say from experience you're wrong about back pressure. A tuned pipe is one thing, a restrictive muffler can only hurt performance. Take it from someone who rebuilds and ports saws for tree services. And your rich lean theory is just ridiculous. The danger of running lean isn't running lean, its lack of oil. Carbon buildup is impossible if you use a synthetic oil. Amsoil sabre, belray h1r (my personal choice), motul, ect
you can never have too many tools
you can never have too many tools
mooseracing
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- Joined
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ilovevocs
Well-known member
Agreed, the backpressure only reduces the efficiency of cylinder scavenging.
justme-
Well-known member
s
*To the op - find out exactly what chain he uses if you're buddy's chain is something you like so you can get it when you need it. Chains have different properties for specific reasons. Different angles for different wood densities, tooth skip patterns, cull/semi chisel ... etc. FWIW semi chisel will stay sharp longer under the exact same conditions. (I know someone here will argue that but it's a fact) also what works well on one specific saw may not work well on another due to bar length, engine size, engine power, and even user circumstances.
Sorry guys - proper cylinder and porting design increases scavenging. Lacking any back pressure from a 2 stroke with all else being equal you'd have enormous charge loses from too much "scavenging". Exhaust needs to get out and fresh charge needs to be kept in. Some resistance is needed to provide that balance. The old designs were simply hole in the combustion chamber from the ports and holes out - fuel charge pushed straight into the cylinder forcing the spent gasses out and taking a lot of incoming charge with it. tossing unburned fuel out with the exhaust is wasted economy, wasted fuel, and in today's understanding higher hydrocarbon emissions. Todays engines are mostly designed to direct the incoming charge away from the exhaust ports so on higher end 2 stroke engines back pressure from an exhaust system are less a factor. A tuned pipe is an engineered restrictive exhaust that provides a specific back pressure and resonant energy echo at a specific rpm or rpm range which gives a performance enhancement to the process of moving the charges correctly. If having no restriction at all was the best solution then having no muffler at all would provide the best performance which it's easy to test and well documented that it doesn't. Do some research on 2 stroke engine tuning - there's tons of info from the 70's dirt bike racing/tuning genre.
As to the rich lean fault - I've never seen it first hand, only educated about it relating to a unit I was repairing who had been running 40:1 when the unit calls for 50:1. It was told to me by a guy who's far more educated in such things and experienced repairing them than anyone else I know and most likely anyone here. I have not had it mentioned in any or my professional training as yet, but I have a few levels to go before I'm a "master".
synthetic isn't the "be-all, end-all" to oil.
If you want your engine to last regardless of what engine it is, use the oil the manufacturer specifies and skip the "hype" from synthetics and Amsoil. There are specific requirements oils must meet - you've all heard of SAE rating for car engine lube oil... there are other ratings for 2 stroke oil. The most common is JASO which in reality applies to water cooled motor scooters and motorcyclesand is the standards all Husqvarna family engines use. An oil can be based on synthetic or mineral oil and meet the JASO or API specifications.
Different types of engine (and even different designs of the same type) have different operating environments and parameters. Different characteristics of the oil are needed for them. The ash level for example helps control cooling - more ash cools the cylinder more but leads to carbon buildup in engines designed for low ash which are in other words designed to run hotter. Synthetic oil is a poorly understood thing and subject to marketing hype, just as engine oil is for cars. There's a reason Texaco and Mobil sponsor race cars. Synthetic refers to the base stock of an oil and used to refer to group 4 which is PAO based. Currently there are multiple base stock group 3 oils that meet the same specs as the group 4 oils and are thus legally allowed to be called synthetic.
In reality synthetic is about the base stock having certain levels of sulphur and aromatics and molecule size not the process which it is refined. That's another misconception - that synthetic oils are created in a lab... synthesised and not refined. PAO comes from a different source but isn't lab created. Good synopsis in simple terms here. If you want to learn about oil do some reading at bobistheoilguy forum.
well, funny as it may sound, the fact is low kick back, or "safety" chain only affects cutting during plunge/boring cuts. Unless you use a saw for a living there is zero benefit not using low kick back chain. Forget the machismo and skip the Tim Taylor grunting at the store clerk. The facts are the facts.
A 3 cyl metro is a "good enough" car for commuting too...
*To the op - find out exactly what chain he uses if you're buddy's chain is something you like so you can get it when you need it. Chains have different properties for specific reasons. Different angles for different wood densities, tooth skip patterns, cull/semi chisel ... etc. FWIW semi chisel will stay sharp longer under the exact same conditions. (I know someone here will argue that but it's a fact) also what works well on one specific saw may not work well on another due to bar length, engine size, engine power, and even user circumstances.
Sorry guys - proper cylinder and porting design increases scavenging. Lacking any back pressure from a 2 stroke with all else being equal you'd have enormous charge loses from too much "scavenging". Exhaust needs to get out and fresh charge needs to be kept in. Some resistance is needed to provide that balance. The old designs were simply hole in the combustion chamber from the ports and holes out - fuel charge pushed straight into the cylinder forcing the spent gasses out and taking a lot of incoming charge with it. tossing unburned fuel out with the exhaust is wasted economy, wasted fuel, and in today's understanding higher hydrocarbon emissions. Todays engines are mostly designed to direct the incoming charge away from the exhaust ports so on higher end 2 stroke engines back pressure from an exhaust system are less a factor. A tuned pipe is an engineered restrictive exhaust that provides a specific back pressure and resonant energy echo at a specific rpm or rpm range which gives a performance enhancement to the process of moving the charges correctly. If having no restriction at all was the best solution then having no muffler at all would provide the best performance which it's easy to test and well documented that it doesn't. Do some research on 2 stroke engine tuning - there's tons of info from the 70's dirt bike racing/tuning genre.
As to the rich lean fault - I've never seen it first hand, only educated about it relating to a unit I was repairing who had been running 40:1 when the unit calls for 50:1. It was told to me by a guy who's far more educated in such things and experienced repairing them than anyone else I know and most likely anyone here. I have not had it mentioned in any or my professional training as yet, but I have a few levels to go before I'm a "master".
synthetic isn't the "be-all, end-all" to oil.
If you want your engine to last regardless of what engine it is, use the oil the manufacturer specifies and skip the "hype" from synthetics and Amsoil. There are specific requirements oils must meet - you've all heard of SAE rating for car engine lube oil... there are other ratings for 2 stroke oil. The most common is JASO which in reality applies to water cooled motor scooters and motorcyclesand is the standards all Husqvarna family engines use. An oil can be based on synthetic or mineral oil and meet the JASO or API specifications.
Different types of engine (and even different designs of the same type) have different operating environments and parameters. Different characteristics of the oil are needed for them. The ash level for example helps control cooling - more ash cools the cylinder more but leads to carbon buildup in engines designed for low ash which are in other words designed to run hotter. Synthetic oil is a poorly understood thing and subject to marketing hype, just as engine oil is for cars. There's a reason Texaco and Mobil sponsor race cars. Synthetic refers to the base stock of an oil and used to refer to group 4 which is PAO based. Currently there are multiple base stock group 3 oils that meet the same specs as the group 4 oils and are thus legally allowed to be called synthetic.
In reality synthetic is about the base stock having certain levels of sulphur and aromatics and molecule size not the process which it is refined. That's another misconception - that synthetic oils are created in a lab... synthesised and not refined. PAO comes from a different source but isn't lab created. Good synopsis in simple terms here. If you want to learn about oil do some reading at bobistheoilguy forum.
vintage nut
Well-known member
I can tell you for a fact that more oil can not harm the engine, as long as you keep the carb tuned properly. Every saw builder I know recommends 32-1 or at the very minimum 50-1, with synthetic oil. The saws live a long happy life on that. Try running a ported saw on 50-1 conventional oil, and its gonna die fast. As for back pressure, yes a tuned pipe is best, but back pressure is the worst. If you look back at old racing stuff, they used to run megaphone pipes, creating negative back pressure. And they ran far stronger than a muffler, and also stronger than a straight pipe, completely disproving your theory.
Finally, safety chains. I don't care what you say, I both build saws, and work as an arborist, and I can tell you without a doubt that a safety chain will not self feed anywhere close to a normal chain, not even considering not being able to bore cut.
If you think synthetic oils are all hype, tear down a saw that has been running 32:1 belray. You will see not a spec of carbon, and a light coating of oil on everything. Same saw ran on conventional will be bone dry and full of carbon. You can claim whatever you want, but I can say from experience that you are wrong on every point you have made.
you can never have too many tools
Finally, safety chains. I don't care what you say, I both build saws, and work as an arborist, and I can tell you without a doubt that a safety chain will not self feed anywhere close to a normal chain, not even considering not being able to bore cut.
If you think synthetic oils are all hype, tear down a saw that has been running 32:1 belray. You will see not a spec of carbon, and a light coating of oil on everything. Same saw ran on conventional will be bone dry and full of carbon. You can claim whatever you want, but I can say from experience that you are wrong on every point you have made.
you can never have too many tools
justme-
Well-known member
the term synthetic is hype - quality oil meeting the intended design specifications is what you want as I explained above. You're specific experiences don't determine the facts anymore than my specific experiences. I've seen internals of engines run on quality oil and low quality oil. Like a Cummins B with over 300K miles that was clean enough to eat out of the oil pan. It was run on Rotella. Similar to my B which has been fed Mobil 1 all but the first 50K and at hard 160K is also clean enough to eat out of. All well and good but running the wrong formulation of that same Mobil 1 means the cam tappets don't have the same additives protecting them from shear stress on the cam lobes. Not a factor in a 7.3L Ford with roller lifters. Different engine, different design, different oil requirement. Our rental stuff is all Stihl and only gets Stihl ultra synthetic. I've seen the insides - plenty clean. I admit all the "info" on them internet seems to hold the same point of view as you do. Plenty of documented stuff about fouling from too much oil, but nothing on what I described.
I'll dig on it in the industry. I'm pretty sure is was brought up in a master level training and that's how he would have learned about it. I know who I can inquire with when I get a chance and will get and forward any supporting documentation I get about it.
jar944
Well-known member
I cant say Ive seen safety chain in a square ground chisel (or even round full chisel in a box store.)
I do have a loop of Oregon V (looks like LGX with a bent raker) I got somewhere. It looks half decent (but it does not have bumpers on the tie links like a typical low kickback chain)
jar944
Well-known member
There is no passage in the carb that will filter out oil molecules. a saw claimed to run @ 50:1 will run just fine @ 16:1 (after carb adjustment)
What I believe you are referring to (or heard) is the fact that more oil in the mix means less gasoline. This will cause a change in the AF ratio. a saw tuned to run @ 16:1 will run very rich if you run a 50:1 or 100:1