New technology is good

[Saw Dr.]

So I just returned from Stihl gold school yesterday. Part of that training is failure analysis. They actually give us new (or test) units and tell us how they want us to blow them up. Then we dissect them and study the innards to see the result. I killed a blower in less than 10 minutes with about 1/2 a thimble full of dirt. That is not the point of this thread.

Another crew got an MS 291. They were supposed to lean it out until it squeaked. The 291 has a bypass circuit on the high. They leaned it until the stop (no limit caps) and proceeded to cut with it for 20 minutes and it would not die. Then we put in a crank seal with 1/2 of the lip missing, and cut for another 10 minutes. Still going. The instructor took the saw and held it wide open for another 5 minutes with no load and a huge air leak. It got so hot that the spark plug became a glow plug, and it would not shut off.......

The saw never did croak. Then they told us that they had tried to fry that saw the week before, and it did the same thing(!!!!!!) A 290 would have croaked as son as the needle started to lean out, as would most other old school stuff. This new generation of saws is really durable. Count me amazed.

 

[Jimmy in NC]

I won't hide I was skeptical of new technology until I rebuilt a TS500. Fuel injection is the stuff on that saw. Never more than two pulls...or it isn't going to run. That's real neat how it kept feeding fuel.

So what let go with the dirt? Top end or bottom bearings?

 

[blsnelling]

Cool stuff!

 

[zogger]

That's very interesting! Sounds pretty good really...

Here is a test, real world, happens daily, did they do it, or something like it, at your school?

Gas jug/can, no stopper, open to outside atmosphere, year old ethanol contaminated gasoline, sort of some mix oil in there...one year old, from like last summer. Run it in the new tech saw. See what happens....will it run or croak....

 

[boxygen]

THanks for sharing. This is the type of thread that we have all been missing for the last several weeks with AS down. You can go anywhere and get/give advice on how to repair a wildthing. THis type of info that is real world, first hand objective information on technology advances is what reallly makes AS a great resource for information and why we keep coming back.

 

[Saw Dr.]

That's very interesting! Sounds pretty good really...

Here is a test, real world, happens daily, did they do it, or something like it, at your school?

Gas jug/can, no stopper, open to outside atmosphere, year old ethanol contaminated gasoline, sort of some mix oil in there...one year old, from like last summer. Run it in the new tech saw. See what happens....will it run or croak....

We straight gassed a new MS170 with one tank of fuel through it. Little stinker went 32 cuts in 16" hardwood before it squeaked. The strato trimmer went 7 mins at WOT on straight gas. They have an MS 360 there that they quit trying after 8(!!!) tanks of straight gas. The piston was not scored. This failure analysis is very interesting.

My point is not that these things are bulletproof. It is to show how much more resistant to abuse they are than previous designs.

Here she is pulling chips with the H seated and 1/2 crank seal.

 

[zogger]

Oh, heck ya it was cool and glad you replied to my question on them trying to run the stuff with questionable rank fuel. And I agree with stihls new tech, however it works, they are gonna keep loyal customers, this is quite impressive.. Not having your equipment bork is a big plus in my book, when the designs are that good.

 

[zogger]

Oh wait, one question, do you mean a 362? Or an upgraded with the new carb jazz old 360?

 

[Saw Dr.]

I mean an old tech regular 360 pro with no fancy jazz. No saw will last long on crap stale gas, regardless of the nameplate on the side. It is obvious you have something against Stihl, so why bother posting here?

 

[o8f150]

to bad this one didn't last that long
<iframe width="560" height="315" src="//www.youtube.com/embed/BVu4HrPCEXM" frameborder="0" allowfullscreen></iframe>

 

[zogger]

I mean an old tech regular 360 pro with no fancy jazz. No saw will last long on crap stale gas, regardless of the nameplate on the side. It is obvious you have something against Stihl, so why bother posting here?

Absolutely not! I have nothing against it, I thought your report was slick! I was wondering about a "bad gas" test, you replied with another good post, which again i thought was cool, but then I thought, just wondered, if you had just mis typed and typed 360 as opposed to the newer tech model 362. That's all man, really. I am basically brand agnostic. I think the reports of that test go to show the quality of their products, and that this was and is a very interesting thread.

I liked the report of some new bypass circuit in the carb, and just thought it was an example of that with the 360, but it wasn't, I just wanted it clarified. Really, no biggee at all man, not sure why you took it that way as it was not my intention to make light of or fun of the report.

 

[Whiskey_Bravo]

Were there any M-Tronic saws there for you guys to abuse?

 

[AKDoug]

Good stuff. I can't wait for my Gold class next year.

 

[Andyshine77]

Remember people, Stihl is in the business of selling products, dealers are consumers as well. If a dealer believes a product is far superior than anything else, they'll push that product even harder. Were dealing with a huge marketing game and every company does it.

I agree, new technology can be great and we all benefit from it in the long run.

 

[jdhacker]

I have a ms 291 its a great saw, one thing bothers me it 4 strokes on the heavy side by my ear. And I can turn the H as far as it will go both ways and it makes no difference in sound.

 

[Saw Dr.]

They bypass circuit is something in the carb design of the newer carbs. The bypass flows about 80% of the main fuel, and the needle only gets the last 20% of adjustment, which is why the high seems like it does nothing on several newer models. Even with the needle shut off, there is still 80% of the fuel being fed.

jdhacker, don't worry about the 4 stroking. They eliminated the "cutoff" style rev limiter on the new Stihl microprocessor coils. Now it just retards the mess out of the ignition timing to stop from over-revving.

 

[Andyshine77]

I believe my 211 is setup this way as well??

 

[Eccentric]

They bypass circuit is something in the carb design of the newer carbs. The bypass flows about 80% of the main fuel, and the needle only gets the last 20% of adjustment, which is why the high seems like it does nothing on several newer models. Even with the needle shut off, there is still 80% of the fuel being fed.

jdhacker, don't worry about the 4 stroking. They eliminated the "cutoff" style rev limiter on the new Stihl microprocessor coils. Now it just retards the mess out of the ignition timing to stop from over-revving.

Certain Homelites (mostly XL-98 demo saws and SXL-925 chainsaws) had 'semi-fixed' H side Tillotson HS carbs similar to what you're describing Tim. This was in the late 1970's/early 1980's. 'Standard' H side setting for those was around 1/4 turn open. Creepy....

 

[Saw Dr.]

I believe my 211 is setup this way as well??

Yup. They were building those yesterday when we toured the factory. The test run cell is very cool. They were serious as a heart attack about NOT taking any pictures.

 

[Mastermind]

Good stuff Tim, thanks for sharing.