RED-85-Z51
Addicted to ArboristSite
I have resources.
Ok, you be the judge
- Thread starter Fish
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romeo
Addicted to ArboristSite
LOL, cotton candy machine.
Woodie
"Cap'n Bullcrap'n"
Speaking of which, where's THALL?
Woodie
"Cap'n Bullcrap'n"
I'm not sure I understand this...how could old gas cause a seizure? I know it's a dumb thing to use, but I thought it would simply prevent the engine from running due to poor ignition/vaporization problems.
But the oil wouldn't have broken down, so it would still be lubricating everything, right?
Help out a rook here.
RED-85-Z51
Addicted to ArboristSite
Old gas lacks the ability to burn properly. It leaves a varnish like coating on everything, as the varnish wont combust. It builds up, and as the heat rises it burns onto the piston, cylinder, crank etc. The buildup gets in on, and behind the rings. The layers buildup, and as more heat is added the layers begin to "melt". They turn into a liquid with the consistensy of cold molasses.
Now inside the carb, varnish is building up, and causing the saw to lean out. More air, less fuel/oil...makes the saw seem to run fine, tons of power. This adds even more heat to the now gummy engine, it turns more rpms. The varnish starts to tighten up the clearances between the reciprocating assembly, and the rotating assembly...more friction..more heat. IT starts to wind down. The rings are now shot, scrubbed to death and over heated...the overheated piston is now black with varnish buildup...and the ports have a thick crust on and around them that has chewed into the piston and skirt on the exhaust side.
If the heat doesnt make it lock up...it will simply shut off from lack of compression.
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This is my take on how it happens, having seen a few first hand. The worst is when it lives through the tank of foul gas, and gets run through a tank of fresh gas. The engine isnt fortunate enough to die...right before death it gets put on the ventilator and gets tortured for another 25-30 minutes before it finally flat lines.
I saw a Ryobi that was so bad that it broke the stamped steel con rod. Looked like a twiseler.
Woodie said:
See above, Red has explained it better than I ever could. But the remainder of what you see on those 310 parts, that's what an 'old gas' seizure looks like. I worked at a Stihl dealership in a small town for three years, and saw over a hundred of those types of problems. These old guys (and some young guys) leave their chainsaw/weedeater/blower/rototiller sit with gas in them for a few months, along with the same can they were using when they put everything away, and expect to fire right back up and pick up where they left off (6-7 months ago).
In certain cases, especially if the piston had a lot of wear simply from being used, the rings will just stick from being varnished and the motor is actually salvageable (to a point where you could install a new piston and rings without too much of a struggle).
Woodie
"Cap'n Bullcrap'n"
Got it...thanks Red and Jacob.
RED-85-Z51
Addicted to ArboristSite
Also after the rings have stuck in the valleys, or worn out...and the saw continues to run, the combusted gasses and flame front will seep down past the rings and further cook the piston, this is what you see in extreme cases like above.
Let me guess. The customer was SAP, therefore the dealer is is way wrong
Okay, just addressing the 'sugar in the gas' bit. Other than clogging up filters, sugar in gas will not do anything. It just turns into wet sugar, about the same as wet sand. Of course that applies to undiluted gas. Not sure what happens with oil/gas mix. I suspect the same thing.
Harry K
Fish
Tree Freak
Tell him his new one runs tighter tolerances,is more highly tuned and is less forgiving of owner abuse
The stihl rep used that one, would you believe that line?
Fish
Tree Freak
Red is that you that wrote this???????
Have you been pulling our leg all this time?????????
If so, good one............
Its obvious, I would say its was WMD and not about oil at all, why does everyone assume its all about oil??????
Oh, maybe this time it is about the lack of, as you were gentlemen
Oh, maybe this time it is about the lack of, as you were gentlemen
Fish
Tree Freak
Ok,
What does SAP and WMD mean?
What does SAP and WMD mean?
ford832
ArboristSite Guru
Personally,no,I wouldn't but I find it immensely discouraging that I think along the same lines as a Stihl rep.
On the other hand,there probably is some truth in it.Older machinery with less compression,more clearance,less advanced timing etc would probably stand this type of thing for a longer period of time.Look at the swill that was commonly used in the older machinery-I don't think you'd get away with it these days.
Simonizer
Addicted to ArboristSite
I think you should evaluate what type of a customer he is. It is obviously his fault, (or whoever put that in the fuel tank). Stihl does have what is called a "good-will" policy. If it was a nice little old man that made a mistake, I would probably warranty it. If the customer is a miserable pr**ck I would tell him it's not worth repairing, buy a new one. I never gamble on rod or crank bearings in a case like this. It will be more cost-effective to replace it. Cheers.
SawTroll
Information Collector
If he used Aspen premixed Alky fuel (as most people do here), this would never have happened......
Most interesting!
Simon, do you judge all Stihl warranty claims? Is there a handbook containing guidelines for this?
In your words, I can be a nice little old man. However, because of the treatment I receive at my local Stihl dealer, I might be considered a miserable pr**ck.
Just wondering where I might stand.
Old man and miserable pr**ck,
Joat
THALL10326
The Champ
LOLOLOLOLOLOLOLOL, I can't resist this, this is worth coming out of retirement. Here goes. Joat I'll be the dayummm judge of whether your a sweet little ole man or a miserable pr-ck, only Judge Roy Hall knows for sure,LOLOLOLOL
Ok back to the island drinking ta ta's, have fun boys.
