How many hours before you have to replace your piston and rings ?
50:1 or 40:1?
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How many hours before you have to replace your piston and rings ?
I put quite a few hours on my work saws,run 25 to 1,air cooled 2 stroke oil, I do not think what I buy is synthetic. I know my saws smokes after i cold start it for a short bit, but once I get them cutting I haven't been noticing any smoke. Carbon build up hasn't been a problem for me at 25 to 1 for about 10 years I've been using it exclusively. Before that I used 32 to 1 in my 034 super until I seized it from accidently putting raw gas in it. I managed to free that engine up and continued using it for many years on 25 to 1 and sold it in good strong running condition. I have been running saws with lots of hours on them and I am fully convinced the heavier mixture is an advantage if you maintain the fuel to air mix properly on well used saws. That means cleaning the air filters before their 3/4 clogged and I find myself adjusting the carb screws now and then to maintain optimum performence ( probably due to the effect of changing weather mostly.).
I am not telling everybody to do as I do, but if your saw is running significant below 100% new when its at its best, IMO you are missing out on getting back some of that lost power and increasing reliability at high gas to oil ratios. If your saw is under warranty,make sure you use a ratio that will not void the warranty. Newer less used engines will do fine at the ratios the factory reccomends, but after a point in their life commpression will start to decrease and oil helps. Carbon is primarily from lack of maintnence and not everybody has the same ability to keep the carb mixture at its optimum so it should be a consideration also to what mix a person uses. Less oil would be more forgiving in regards to running dirty air cleaners, or running a rich carb setting.
And there is plenty more to read in past threads, no since in me repeating myself, I probably already did.
I am not telling everybody to do as I do, but if your saw is running significant below 100% new when its at its best, IMO you are missing out on getting back some of that lost power and increasing reliability at high gas to oil ratios. If your saw is under warranty,make sure you use a ratio that will not void the warranty. Newer less used engines will do fine at the ratios the factory reccomends, but after a point in their life commpression will start to decrease and oil helps. Carbon is primarily from lack of maintnence and not everybody has the same ability to keep the carb mixture at its optimum so it should be a consideration also to what mix a person uses. Less oil would be more forgiving in regards to running dirty air cleaners, or running a rich carb setting.
And there is plenty more to read in past threads, no since in me repeating myself, I probably already did.
Lewis Brander
Addicted to ArboristSite
Fuel Mix ratios:
Another point in question is seal lubrication. I have a bunch of old saws that as I have said I run with a roughly 24/1 oil mix. Yes, some have sat for years, but the old things run and the seals are just fine. I read more and more about newer saws not idling right and seal replacement. I realize that the newer saws are higher reving saws, but with the newer seal materials it would seem the seals should last longer than they sometimes do. Just seems to me that a tad more lube may prolong seal life, especially in these newer higher reving saws. I'm not talking about these modded woods saws or racing saws, for I don't have much interest in them. Any comments about seal life in the newer saws?
Another point in question is seal lubrication. I have a bunch of old saws that as I have said I run with a roughly 24/1 oil mix. Yes, some have sat for years, but the old things run and the seals are just fine. I read more and more about newer saws not idling right and seal replacement. I realize that the newer saws are higher reving saws, but with the newer seal materials it would seem the seals should last longer than they sometimes do. Just seems to me that a tad more lube may prolong seal life, especially in these newer higher reving saws. I'm not talking about these modded woods saws or racing saws, for I don't have much interest in them. Any comments about seal life in the newer saws?
sprdave
ArboristSite Lurker
I don't even know. I know I can use up over a gallon (4 liters) of premix before I replace rings. At 50:1 and if I get 20 mpg that's 1000 miles. I mix leaner than that and I might not get all of 20 mpg. Every time I replace rings I doubt that I wated long enough. If you follow the manual recomendation, it's something like "every three races" The last time I replaced a piston, I saved the old piston. It's still way outside of service spec for the replacement size. I really ride hard, too.
Here's another tidbit of info that saw folk might be interested in. Cast pistons don't get smaller so much from wear, as they do from shrinking. The piston actually shrinks from getting hot and cooling down. Forged pistons do it as well, but hardly in comparison to the cast pistons.
Lakeside53
Stihl Wrenching
lolol - the lowly pro saws get over 2000-2500 hours! hard to measure mileage..
sprdave
ArboristSite Lurker
I know. I think that's funny. My mom's has an 026 that I think she's had since 89. Two hours a weekend would be around 2000 hours. It still rips. I don't see it ever needing a top end. I kinda want to, just to see what it looks like inside.
Hi Lewis; I too do as you in that I like to work on the older vintage saws mostly IEL- Pioneers but also have others from mid 1940`s to mid 60`s. I take them running or not and strip them down to the crankshaft and replace bearings and seals. Make new gaskets and rebuild them with new rings,sometimes pistons if required and all fuel lines carb kits etc. The older saws seldom need new seals and are tight when I do a vacuum test before disassembly so maybe the high oil ratio keeps the seals more pliable. The older saws did not turn up such high rev`s and I think they run cooler as they had little muffler restriction and used more fuel and oil. It was not until the early eighty`s that my saws started to heat the gas in the tanks that would cause the saw to flood. I started to open up my mufflers and they were noisier but stopped flooding and running hot. The seals never failed either on these saws so maybe heat is causing the seals to fail. I have had to replace a lot of seals on the saws from the mid 80`s on up and bearings also but thought it is because they run too fast on less oil and make more heat. I personally have opened up the intakes on my own saws as well as the exhaust ports and the mufflers and do not have problems with the bearings or seals but I also run my saws under the recommended high rpm settings and slightly rich as well. I have a tach but don`t use it to set my saws for top speed but rely on my ear to set the saw for power in the cut not when it is running free or unloaded. This has worked for me but may not work for others and is my experience only. Pioneerguy600
Lewis Brander
Addicted to ArboristSite
Good poiints:
Pioneerguy600: I believe you have made some good poiints. As you say the older saws didn't rev as much, were less restricted, ran higher oil ratios and produced less heat and with a properly adjusted carb and no air leaks they ran cooler. My newest saw is a Poulan 3400 CAV. and she is totally original down to the spark plug and used very little. She calls for a 16/1 mix. of poulan oil. I now run full synthectic and run her at 32/1 mix. Originally she seemed to me to run hot, especially in the summer heat, even with the 16/1 mix and the carb adjusted as you say by ear. The muffler was way restricted. Muffler outlets were only 20% of the exhaust port area. I opened up the muffler to 80% of the exhaust port area and the saw ran much better. I also removed the spark arester screen and opened up the holes in the piece the screen was wrapped around. I also put a bit larger screen inside the muffler where I drilled holes to open her up in the front of the muffler. At 32/1 with a properly adjusted carb the saw breaths much better, runs cooler and runs like a totally different saw. About the only other improvement would be to change from 3/8" chipper chain to say a round ground/square ground chisel chain. As you say there are more newer saws with seal and bearing failure. I truely believe that runing a saw say at a 40/1 ratio with todays oils and slightly richer mixtures would greatly improve the life of the saw. Running a saw say at 50/1 or higher ratios and tuning the carb for the saws Max rpm range (leaning out the carb) only reduces the max life of the saw in my opinion. What you would gain in performance, would only reduced the saws life expectancy and cost more in repairs in the long run. A saw engine is air cooled, but more importantly is cooled by the vaoprized gas traveling through the crankcase. Lean out the mixture and use less oil and you will have more heat. Someone mentioned brown deposites, like a varnish, in thier saws crankcase. To me this only shows the saw was running at a hotter temperature and the fuel mixture was cooking to the sides etc of the crankcase and not properly lubricating and cooling the saw. There may be other opinions/arguements form others, more in the know than I, but these are my thoughts. These newer so called EPA carbs present a problelm, in that they are not adjustable, from what I can gather and alot of them are being replaced with adjustable carbs. In this case you are stuck wiht running the oil mix called for, cause adding more oil to the mix wll only lean out the air fuel mixtue and cause the saw to actually run leaner, so either opening up the carbs jets a bit or replacing them with larger ones, or puting on an adjustable carb is all your left with. You, in my opinion, can't open up the mufflers on these new saws without retuning the carb to a richer air/fuel mixture. There's not much that I can see you can do to these EPA saws without modifying the carb to compensate for any changes. The carbs usually are set on the lean side and any changes/mods will only make the saw run leaner. OK, not trying to write a book, but as said, some interesting thoughts and observations. Everyone take care. Lewis.
Pioneerguy600: I believe you have made some good poiints. As you say the older saws didn't rev as much, were less restricted, ran higher oil ratios and produced less heat and with a properly adjusted carb and no air leaks they ran cooler. My newest saw is a Poulan 3400 CAV. and she is totally original down to the spark plug and used very little. She calls for a 16/1 mix. of poulan oil. I now run full synthectic and run her at 32/1 mix. Originally she seemed to me to run hot, especially in the summer heat, even with the 16/1 mix and the carb adjusted as you say by ear. The muffler was way restricted. Muffler outlets were only 20% of the exhaust port area. I opened up the muffler to 80% of the exhaust port area and the saw ran much better. I also removed the spark arester screen and opened up the holes in the piece the screen was wrapped around. I also put a bit larger screen inside the muffler where I drilled holes to open her up in the front of the muffler. At 32/1 with a properly adjusted carb the saw breaths much better, runs cooler and runs like a totally different saw. About the only other improvement would be to change from 3/8" chipper chain to say a round ground/square ground chisel chain. As you say there are more newer saws with seal and bearing failure. I truely believe that runing a saw say at a 40/1 ratio with todays oils and slightly richer mixtures would greatly improve the life of the saw. Running a saw say at 50/1 or higher ratios and tuning the carb for the saws Max rpm range (leaning out the carb) only reduces the max life of the saw in my opinion. What you would gain in performance, would only reduced the saws life expectancy and cost more in repairs in the long run. A saw engine is air cooled, but more importantly is cooled by the vaoprized gas traveling through the crankcase. Lean out the mixture and use less oil and you will have more heat. Someone mentioned brown deposites, like a varnish, in thier saws crankcase. To me this only shows the saw was running at a hotter temperature and the fuel mixture was cooking to the sides etc of the crankcase and not properly lubricating and cooling the saw. There may be other opinions/arguements form others, more in the know than I, but these are my thoughts. These newer so called EPA carbs present a problelm, in that they are not adjustable, from what I can gather and alot of them are being replaced with adjustable carbs. In this case you are stuck wiht running the oil mix called for, cause adding more oil to the mix wll only lean out the air fuel mixtue and cause the saw to actually run leaner, so either opening up the carbs jets a bit or replacing them with larger ones, or puting on an adjustable carb is all your left with. You, in my opinion, can't open up the mufflers on these new saws without retuning the carb to a richer air/fuel mixture. There's not much that I can see you can do to these EPA saws without modifying the carb to compensate for any changes. The carbs usually are set on the lean side and any changes/mods will only make the saw run leaner. OK, not trying to write a book, but as said, some interesting thoughts and observations. Everyone take care. Lewis.
yungman
Addicted to ArboristSite
I lean my oil down to no more oil than about 45:1 and I ran three tankful of mix through my C4 blower and open the muffler, valve cover and plug to check the condition. To my surprise, I still see plenty of oil around the rocker arm and other parts under the valve cover. I think I can conclude 50:1 is not too little oil!!!! Just a piece of information someone here might be interested.
It definitely have more oil inside the engine than the few old 2 cycle engines I opened up to learn. I wonder whether in the hybrid engine, mix pass through a much longer path inside the crankcase before going into the combussion chamber so more oil settled out from the mix and remain in the crankcase and moving parts. Could this be the reason why Stihl even ok the use of leaner than 50:1 with their Ultra!!!??
One disappointing thing is I still see black deposits inside the muffler and exhaust port, I guess Echo Power Blend is no better than Mobil 2T or Shindaiwa One regarding to dirtying up the muffler. I wonder why the muffler and exhaust port of the Shindy C4 blower is so much dirtier than the Echo 21.2cc Hedge trimmer motor. I opened the Echo and look at the exhaust port and muffler, there was no black stuff, period!!! That was after a few tankful of gas!!! Things were shinny inside!!! Why???
It definitely have more oil inside the engine than the few old 2 cycle engines I opened up to learn. I wonder whether in the hybrid engine, mix pass through a much longer path inside the crankcase before going into the combussion chamber so more oil settled out from the mix and remain in the crankcase and moving parts. Could this be the reason why Stihl even ok the use of leaner than 50:1 with their Ultra!!!??
One disappointing thing is I still see black deposits inside the muffler and exhaust port, I guess Echo Power Blend is no better than Mobil 2T or Shindaiwa One regarding to dirtying up the muffler. I wonder why the muffler and exhaust port of the Shindy C4 blower is so much dirtier than the Echo 21.2cc Hedge trimmer motor. I opened the Echo and look at the exhaust port and muffler, there was no black stuff, period!!! That was after a few tankful of gas!!! Things were shinny inside!!! Why???
Last edited:
Does the Echo have a catalytic muffler?
Hugenpoet
Addicted to ArboristSite
It's replies like this that make this forum invaluable. Staight to the point good advice. Thanks.
Esteban
ArboristSite Lurker
foxeye
ArboristSite Member
Jet fuel Jet-A or JP5 or JP8 is more like kerosene than gasoline. Best to go with the 115 octane Aviation gas.
Do they still market Sunoco 260 anymore?
**JT**
New Member
I've been running Amsoil Synthetic for 7 years now at 100:1 in EVERY single piece of two cycle equipment we have. Absolutely NO engine failures during that time even with our trimmers that run 5 days a week on a lawn crew.
OilHead
ArboristSite Guru
I'd be scaired to run that ratio with the reformulated fuel we have here.
