Will Strato charged motors be less reliable long term?

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tree monkey

tree monkey

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yeh and that is husky's answer to everything, buy out the competition. unfortunately it has done nothing for reliability.

sorry ,i own both, sell one brand and strongly disagree. m-tronic saws are not problematic, the same cannot be said for auto-tune saws. husky's are lighter and a little quicker, but they do not hold a candle to stihl when it comes to reliability. i have 200 plus maint. techs under me here, 40 of them are small engine. i can tell you we do very little warranty work, most of the issues these days are due to operator error.

Corporate use of its size to crush competition by lobbying regulators for rules that favor it's technology in the name of saving the earf. Your days of field repairing your saw are soon over. Thanks world.

agreed
 
7sleeper

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This topic is in my eyes totally sensless. Why? Because how many saws of yesteryears are really in regular use today? Probably zilch! No one uses a 041 on a regular basis anymore. And those used in production felling all probably died decades ago. We have the same situation today, pro saws are designed for production felling and after 3-5 years of use have ended their life cycle. That a bunch of hobby firewooders are afraid that their pro saw will not last as long as the saws of the past is simply absurd. And if we advance to the last production cycles f.e. Stihl 260 or Husqvarna 353/346 we have the same situation. How many really exist after 3-5 years of production felling?
And now to the next question, who wants to still use their saw after 3-5 years of production felling and not upgrade to the next improved model?

7
 
bwalker
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This topic is in my eyes totally sensless. Why? Because how many saws of yesteryears are really in regular use today? Probably zilch! No one uses a 041 on a regular basis anymore. And those used in production felling all probably died decades ago. We have the same situation today, pro saws are designed for production felling and after 3-5 years of use have ended their life cycle. That a bunch of hobby firewooders are afraid that their pro saw will not last as long as the saws of the past is simply absurd. And if we advance to the last production cycles f.e. Stihl 260 or Husqvarna 353/346 we have the same situation. How many really exist after 3-5 years of production felling?
And now to the next question, who wants to still use their saw after 3-5 years of production felling and not upgrade to the next improved model?

7
But that's not really what I was thinking at all. Just a curiosity if the strato designs come with a down side.
And your right, new and better designs come out all the time.
 
STIHLTHEDEERE

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So Husky is conspiring with the EPA to drive other OPE mfg out of business?
That's rich!
if husky continues on their existing path, they will run themselves out of business. and not sure about the husky design, (which is/was surely someone elses), but stihl strato engines last/run just as long as the models they replaced. as previously stated, most of the problems/failures these days are due to operator error.
 
Chris-PA

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They run much leaner and leaner equals hotter.
I have been running the snot out of a Redmax 8000 blower since the early 2000's and its never missed a beat. However, it doesn't have a compensating carb like the newer saws have. FWIW it's been on a diet of 32:1 since day one.
They do not run leaner at all. You (or the feedback system) tune them so that they are the same fuel/air ratio as any other saw. In terms of fuel/air ratio the mix that passes through the case is much, much richer than a non strato saw, although I can't see why that matters. The rich fuel/air mix arrives much later and mixes with the fresh air that is already there to yeild a mix that is adjusted to be correct. The difference is that there is much less unburned fuel blowing out the exhaust - fuel that costs you money, makes no power and damages your health when you breathe it.

There are a lot of misconceptions about how strato saws work that contribute to these concerns. I run mine on 40:1.

Corporate use of its size to crush competition by lobbying regulators for rules that favor it's technology in the name of saving the earf. Your days of field repairing your saw are soon over. Thanks world.
I'm no fan of big corporations, but this is absurd. The emissions limits came first, and various manufacturers tried various approaches to meet them.

McCulloch tried whining, crying and lobbying, and when that didn't work they admitted that they had invested all their money in other things than product development, so they sold their name and when out of business.

Most did the cheapest thing and set the carbs lean, stuck limiters on the adjusters and shove a cat in the muffler. Including Husqvarna, although they apparently were working on a form of strato too.

Some smaller companies (Zenoah) actually invested in developing engine technologies to address the most basic problem of scavenging losses, and succeeded in a major breakthrough that requires no additional moving parts. But they were small and could not capture enough market share so they sold their business to Husqvarna - still, Husqvarna made an investment. Further, they invested in developing feedback carbs to address the other main culprit of puking raw fuel out the exhaust, which are the carbs that cannot hold a fixed fuel air ratio with varying rpm.

As for repairing saws, maybe that applies to you but I'll still be working on my tools. I've ported my strato saws while preserving the strato function, and the feedback carb systems are pathetically simple.
 
heyduke

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Yes they are a wide open or spudder out set up glad moto x bike didnt have strato crap. I like my pre strato saws

i'm not sure what you're trying to say here but... i suggest you try a husqvarna 575, possibly the best 70cc class saw ever built, and a strato. it has a smooth wide power band that reminds me of a saw from the 1970's.

and what chris-pa said above, stratos aren't designed to run leaner, like most modern stihls, they are designed to blow less raw hydrocarbons out the muffler by injecting fresh air in front of the charge. you can actually tune them richer. the first time i worked on one, i did a lot of head scratching. i'm still not sure what the actual or effective displacement is in a strato engine. i was sure that stratified charge was just another scam perpetrated by epa/carb. i was wrong. people have such short memories. we've forgotten when the first honda civics were introduced, 1500cc's, 50+mpg, no cat needed, abundant power, stratified charge.
 
bikemike

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i'm not sure what you're trying to say here but... i suggest you try a husqvarna 575, possibly the best 70cc class saw ever built, and a strato. it has a smooth wide power band that reminds me of a saw from the 1970's.

and what chris-pa said above, stratos aren't designed to run leaner, like most modern stihls, they are designed to blow less raw hydrocarbons out the muffler by injecting fresh air in front of the charge. you can actually tune them richer. the first time i worked on one, i did a lot of head scratching. i'm still not sure what the actual or effective displacement is in a strato engine. i was sure that stratified charge was just another scam perpetrated by epa/carb. i was wrong. people have such short memories. we've forgotten when the first honda civics were introduced, 1500cc's, 50+mpg, no cat needed, abundant power, stratified charge.
No they not designed to run leaner just better for emissions. I did run a few different master mind husky stratos and they were nice saws i do like the older 372xp and 572 xp air injection saws they are great stock and mean modded.
 
Franny K
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I have a strato engined saw built in 2005. Probably won't hold up nlong term.

There's probably 20% less mix passing through the case per unit time - so if that concerns you use 20% more oil, which is like going from 40:1 to 32:1. I don't worry about it at all and I've read nothing to make me think there is any reason for concern.

I also don't know where the idea that they run hotter comes from.
If there is 20% less mix then the heat of vaporization (negative) is going to be less. It may well be less vaporization cooling in some places vs other places as well. Whether this is where the run hotter idea comes from not that I knew of the idea prior.

Personally I think the coatings in the cylinder will get better if the manufacturers choose to put as good a coating as they can on the product in question. Oils also seem to improve.
 
bikemike

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If there is 20% less mix then the heat of vaporization (negative) is going to be less. It may well be less vaporization cooling in some places vs other places as well. Whether this is where the run hotter idea comes from not that I knew of the idea prior.

Personally I think the coatings in the cylinder will get better if the manufacturers choose to put as good a coating as they can on the product in question. Oils also seem to improve.
Yeahya. I also believe the running hotter is due to tuning and maybe restrictive exhaust. All engine will perform good at a moderate temp and too hot they will lag a bit
 
ArcticOverland

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Awww. All of you guys are cheating. You're bringing guns to a food fight. Damned facts and accurate information will ruin this thread.

Can we not all just play dumb and laugh at people who don't understand that modern technology does not automatically equal junk?

I really want to learn more from Stihlthedeere, the guy with the inside scoop on everything Hooskervarning. Guy's had some saws from them back when Bruce Willis still had a full head of hair and they obviously somehow put him on the quality control, manufacturing, R&D and strategic planning mailing lists as a result.

Yeah, stratosaws are junk. Especially huskydoohicky jap made blah blah blah....
 
Franny K
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In terms of fuel/air ratio the mix that passes through the case is much, much richer than a non strato saw, although I can't see why that matters.

I think this is a simple and short important piece of information that goes to answering the question in the title. There is a chance some design or designs that make it to market the clean air gets around bearings instead of the mixed air.

Some place near your strato transfer ports, the ones that pass air only it would stand to reason there is less lubrication. The guys that take these things apart probably can tell if it is an issue.
 

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