Carbon Analysis On Piston Crown

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I'm with the group that also says 89 pump gas, Stihl Ultra or Baileys synthetic at 50:1, during the fall and winter firewood cutting we've burned as much as twelve gallon of mix in a week, prolly average between 7-8.5 gallon during the average cutting week. I know we're not milling, but the guys that run the saws all the time, I run as much as health allows, run the pizz out of them, they get shut down for fuel and bar oil, one fifteen minute break between eight and twelve, thirty minute lunch and one fifteen minute break between lunch and 0'dark thirty. I can't image much harder use, unless milling.
We do noodle alot of out bigger pieces and that practice seems as tough as any on a saw. I think 50:1 with a good oil is plenty of protection unless milling. I'll prolly start a can of worms but the Stihl tech I've used for years claims that the saws will survive on 70:1-80:1 during "normal" operation during
Stihls engine testing. I can't say if he's full of **** or that's the skinny from Stihl. I just know that Ultra or Baileys syn at 50:1 works for us in tough conditions with no excessive carbon fouling or saw failure.

I know I prolly violating some rule, but for those interested, do a little searching on Bob's the Oil Guy, it's a site for oil related topics just as involved as this site is with saws and the like. Tons of good info there.

I've been a member over there for sometime now. They had a guy do a very in depth review of R50. Befor he started running R50 he rebuild the engine, and took measurements of the piston, piston rings and the pin. He than ran the oil for a year than did a complete rebuild. The results were impressive, very little ware, that's what made me start running R50.

I've been told by too many people that know way more than most of the regulars on this site, including TW, E Copsy and Ed Heard to run 32:1. In fact I've been running my 2 stroke equipment on 32:1 for the last 20 years and I've never seen any carbon scoring. And to be honest I've seen more carbon issues in engines running 50:1.
 
I'm curious as to whether or not this is normal carbon formation on a piston crown. This is the P&C from my new MS440. It has only seen maybe a dozen tanks of fuel. The saw has not been run excessively rich, or lean for that matter. What's odd is the the combustion chamber and exhaust port are both clean. The carbon on the piston crown was extremely hard and very difficult to remove.

Most of you know that I run Klotz R50 at 32:1. My questions are this. Is this normal? If not, is this the result of running R50? Is it the result of running 32:1? What do the masses think. And please don't just blurt out, oh you're running it too rich. Give me a reason why you think what you do.



844997139_PLnLi-L.jpg






This is what I call clean.




4546697140_d6d2ae7cf4_b.jpg






MS660 cylinder, 6-7 tanks of Amoco Ultimate premium unleaded(10% ethanol) mixed with Stihl Ultra @ 50:1, with one ounce per gallon Klotz Super Techniplate added.


This photo was taken after the saw was used to buck 40" White Oak, so the top end was under plenty of load. No pic of the piston, but what was on the crown wiped off with a paper towel.

Notice how clean the plug is.


My $.02

...
 
This is what I call clean.




4546697140_d6d2ae7cf4_b.jpg






MS660 cylinder, 6-7 tanks of Amoco Ultimate premium unleaded(10% ethanol) mixed with Stihl Ultra @ 50:1, with one ounce per gallon Klotz Super Techniplate added.


This photo was taken after the saw was used to buck 40" White Oak, so the top end was under plenty of load. No pic of the piston, but what was on the crown wiped off with a paper towel.

Notice how clean the plug is.


My $.02

...
I'd rep you if it'd let me.

If I'm remembering right, you cut timber professionally, no?
 
This is what I call clean.

MS660 cylinder, 6-7 tanks of Amoco Ultimate premium unleaded(10% ethanol) mixed with Stihl Ultra @ 50:1, with one ounce per gallon Klotz Super Techniplate added.


This photo was taken after the saw was used to buck 40" White Oak, so the top end was under plenty of load. No pic of the piston, but what was on the crown wiped off with a paper towel.

Notice how clean the plug is.


My $.02

...

That is certainly clean!
 
Andy, no arguement from me, just saying what has worked for us, know doubt the oil you guys use is well rescearched and a quality product, no disrespect intended. My 2nd cousin is a third generation logger, they run stihl saws and the old orange bottle dino, they run a huge operation compared to our little firewood business, they run 40:1 and have prolly since the early 70's.
They don't have saws fail due to mix issues, but abuse and just plain wearing them out, they slap a new oem jug and slug on and go unitil the bearings are shot and then do a total teardown, they got a 044 on it's third rebuild. They just refuse to give up their old saws, they like em.

No two of us on here prolly use a saw in the same way day in and day out.
I run them wot, when I stop them, I've never give it a thought to let them cool down, just gas, oil and go. As fuel gets worse I may have to resort to using a better lube, who knows. I just know the results we get, little if any carbon residue, great running, and no performance issues related to the mix or it's effects on the internals, prolly can be duplicated by several combinations of mixes and quality levels of fuel.
 
It could be the Super unleaded fuel, like some have suggested.


Maybe some fuel's don't burn clean with certain types of 2 stroke oil ?


an additive miss-match ?
 
My fault in the fairness of full disclosure, we do add a half a can of sea foam to a five gallon can of mix every five or six five gallon cans we use. This may be contributing to the clean internals. I do think the fuel stabilizers in Ultra and Baileys work great, I'm cheap in some ways, hate to waste fuel, we've used some mix that's been left in a almost empty can, that only God knows how old it was and it ran fine, prolly not more than three months old. I know not a good practice.lol
 
It could be the Super unleaded fuel, like some have suggested.


Maybe some fuel's don't burn clean with certain types of 2 stroke oil ?


an additive miss-match ?

Orrrr, it could be from running nearly twice the rated amount of oil. Nah, surely not! :)
 
I'd rep you if it'd let me.

If I'm remembering right, you cut timber professionally, no?


No, I cut metal professionally >vvvv


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I run saws for enjoyment, but I owned a tree service for five years and I have run saws for over thirty years.


:cheers:


.
 
This is what I call clean.




4546697140_d6d2ae7cf4_b.jpg






MS660 cylinder, 6-7 tanks of Amoco Ultimate premium unleaded(10% ethanol) mixed with Stihl Ultra @ 50:1, with one ounce per gallon Klotz Super Techniplate added.


This photo was taken after the saw was used to buck 40" White Oak, so the top end was under plenty of load. No pic of the piston, but what was on the crown wiped off with a paper towel.

Notice how clean the plug is.


My $.02

...

50:1 plus an ounce would be ~36:1
 
Just go back to the orange bottle stihl oil. I ran that crap for years and never had a saw fail and honestly never looked at the piston simply because they never petered out. I will admit that my saws ran a little stronger when I went to ultra and my daily headaches subsided. Amsoil was just conevenient since I got a dealers license for my cars and equipment and it is quite a bit less than ultra not that I would call it better but it does smell better and burns a little cleaner but theres no stabilizer added to it so for the guys that arent using gas daily or weekly mix it as needed.
 
I've been running Maxima 927 Castor at 40:1 in my saws. I don't have the bottle in here to look at but I remember it saying it has esters in it along with the degummed castor oil. I haven't looked at any of the pistons lately but the saws run good on the stuff plus it smells good. In fact I just got another half gallon of the stuff and that will mix roughly 21 gallons of gas. I tend to run my saws on the edge and my understanding is the Maxima 927 is excellent in that respect as it's designed for racing 2 stroke dirtbikes. So long as my plugs are that nice brown chocolate chip cookie color I don't get to excited. Ok I am rambling now, the real question is why Brad's piston has alot of carbon on it and for that I don't have a concrete answer.
 

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