Will Strato charged motors be less reliable long term?

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chris-pa-

this tread got me to looking at the "xtorq" 372. from what i can see in the ipl, it lacks the separate fresh air intakes and has an ordinary looking carb. however the carb is different from the non-strato 372 and its walbro model number has a prefix of "DP" which i assume stands for "dual path." i've never worked on one of these so i'm really just guessing.

also, if the hypothesis, "stratified charge saws don't get enuff oil" was supported by experimental data, the dumpsters would be full of smoked chainsaws. the only data shown here is that davey tree's stihl 362's have a lot of failures and early husky 575 had some crank bearing failures, a problem that was corrected. it's been more than ten years since this technology came to market. you'll have to pry my 575 from my cold, dead hands. and it may kill me because it runs so long on a tank of mix i never get a break.
The dual path carbs are pretty simple - take a regular saw carb with a built in choke, open the choke and throttle full and look down the opening. You'll see that the main and idle fuel outlets are all on one side of the plates, and there is a pretty small gap between the choke and throttle plates. I seriously doubt much fuel ends up in the air flow path on the top side of the those plates, but it doesn't matter as they are set up to work that way and both paths mix together after the throttle plate anyway.

Now take that carb and add a fin to fill in that small gap between the plates, and feed the outlet into a manifold that is split and has a divider that matches up to the throttle plate when it is open - now the two flow paths are really separated, and one feeds the strato inlet while the other feeds fuel mix into the case.
 
chris-pa-

this tread got me to looking at the "xtorq" 372. from what i can see in the ipl, it lacks the separate fresh air intakes and has an ordinary looking carb. however the carb is different from the non-strato 372 and its walbro model number has a prefix of "DP" which i assume stands for "dual path." i've never worked on one of these so i'm really just guessing.

also, if the hypothesis, "stratified charge saws don't get enuff oil" was supported by experimental data, the dumpsters would be full of smoked chainsaws. the only data shown here is that davey tree's stihl 362's have a lot of failures and early husky 575 had some crank bearing failures, a problem that was corrected. it's been more than ten years since this technology came to market. you'll have to pry my 575 from my cold, dead hands. and it may kill me because it runs so long on a tank of mix i never get a break.
I don't think anyone said that stray say don't get enough oil. They do see much less lubrication so its natural to ask if this effects longetivity.
 
I don't think anyone said that stray say don't get enough oil. They do see much less lubrication so its natural to ask if this effects longetivity.

They see an average of 20% less throughput.........I'll agree to that.

Are you saying that the fuel mix at say 40:1 that enters the cases of strato and non-strato saws, remains 40:1 in the non-strato saws and changes to 50:1 or so for the strato saws?

I think from Scott's observation of the bottom end being oily and the piston being dryer, is due to more air (not air/fuel) through the transfers and across the piston, but the bottom end is doesn't get this drying effect.

I'm no expert, way over my head and probably sticking my foot in my mouth.
 
They see an average of 20% less throughput.........I'll agree to that.

Are you saying that the fuel mix at say 40:1 that enters the cases of strato and non-strato saws, remains 40:1 in the non-strato saws and changes to 50:1 or so for the strato saws?

I think from Scott's observation of the bottom end being oily and the piston being dryer, is due to more air (not air/fuel) through the transfers and across the piston, but the bottom end is doesn't get this drying effect.

I'm no expert, way over my head and probably sticking my foot in my mouth.
That's not what I said at all. Go back and read what I wrote. I spelled it out plainly.
 
Not a fanboy, just a good dealer who knows and sells the best. And not calling names,just stating the clearly obvious. Stihl has no competition, they are the competition, not single other brand can touch their sales numbers, not even close.And FYI, I own/ run Stihl, echo , and jonsered.........
You more sound like a little brat who got the chance to run dad's chainsaw this weekend, unfortunately for Stihl it was a Stihl saw.
 
Not sure if this has been covered, but the 365 XT's are not holding up as well as the old school 365's in a production environment.
And no, these guys don't take real good care of them. Might be the strato, but might be the fact the strato piston weighs a ton...
That's all I have..
 
Not sure if this has been covered, but the 365 XT's are not holding up as well as the old school 365's in a production environment.
And no, these guys don't take real good care of them. Might be the strato, but might be the fact the strato piston weighs a ton...
That's all I have..
Interesting. What sort of commercial work are they doing with 365's?
 
Not sure if this has been covered, but the 365 XT's are not holding up as well as the old school 365's in a production environment.
And no, these guys don't take real good care of them. Might be the strato, but might be the fact the strato piston weighs a ton...
That's all I have..

to be honest i am not a fan of the XT compared to the OE as well. that said i know of a few 372XT's used on the coast with more then 2 years on them that still run. not sure what those guys in MO are doing to them with those little 24" bars LOL but here they are running 33" average and i have even seen them with a 42" once in a while (crazy i know but fallers don't know any better). so far what i am seeing is they last just as long as an OE 372. just a stupid heavy piston like you say making them sluggish. there is no denying the snap of the OE 372. the XT is still a very usable saw and i'll take it before the comparable stihl anyday.
 
to be honest i am not a fan of the XT compared to the OE as well. that said i know of a few 372XT's used on the coast with more then 2 years on them that still run. not sure what those guys in MO are doing to them with those little 24" bars LOL but here they are running 33" average and i have even seen them with a 42" once in a while (crazy i know but fallers don't know any better). so far what i am seeing is they last just as long as an OE 372. just a stupid heavy piston like you say making them sluggish. there is no denying the snap of the OE 372. the XT is still a very usable saw and i'll take it before the comparable stihl anyday.

The XT 365/372's are fine, but suffer from people not tuning them properly, trying to get the same rpm's the old saws had. Tune to 13,000 or a little less and they will run fine. That's where all the failures came from. Small bar, too many rpm's, with a heavy piston, = boom. The way most so called professionals run and maintain their equipment is amazingly pathetic.
 
The XT 365/372's are fine, but suffer from people not tuning them properly, trying to get the same rpm's the old saws had. Tune to 13,000 or a little less and they will run fine. That's where all the failures came from. Small bar, too many rpm's, with a heavy piston, = boom. The way most so called professionals run and maintain their equipment is amazingly pathetic.
What makes the piston so heavy?
 

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