Khntr85
Addicted to ArboristSite
With @blsnelling here to give you tips, you are in GREAT hands now!!!
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D
Deleted member 135597
Guest
I will type up a full detailed report of everything that I've done with saw since new later. I've only run the thing 3 times so I know all the details since new. Gotta take care of some things first though.
D
Deleted member 135597
Guest
ok, for starters I never knew something was wrong with the saw till I saw the compression readings. Before I tore it down, it popped on the 1st or 2nd pull cold, switched to high idle and started with 1 pull. It seemed to have plenty of power, but again I have never ran a saw this big so don't have any experience to compare it to. At the beginning of this post you can see the oak I just bucked up with a 25 inch bar with full chisel chain. Again, didn't notice any issues at all. It starts with 1 pull hot everytime.
Since new, I fell one oak tree with it with saw totally stock out of dealer. bucked that tree up and could tell it was four stroking in the cut. Since new I have been running 100LL with stihl ultra 50:1.
After that tree, I pulled the limiters and trimmed the tabs, and reinstalled the limiters. I tuned the saw to 12900 rpm because I thought red line was 13k. I fell and bucked up another big oak. Now this is possibly where I may have over leaned the saw but not sure. while bucking this tree up I was tuning with a tach and checking it in the cut but 99 percent sure I was not over lean but I guess it's possible maybe one or two cuts were made with the saw lean.
Now I got a dual port muffler cover. The cylinder was scored already at this time, I saw it when I swapped covers. I retuned the saw to 13500 now because I was corrected that redline was not 13k. I went and cut a bunch of cookies from a downed beech tree to test it out, It ran good. Now remember, The cylinder was scored before I even tuned it leaner purposefully. Now I could really tell it would clear up good in the cut and when I would lift it would four stroke.
This brings us to the start of this thread. For ***** and giggles I wanted a baseline compression reading so in the future if I started having problems I could go back to a "new" saw compression reading. Max reading I received after about 5 pulls was 110. Everyone said my gauge was bad so I disregarded the reading. I dropped and bucked up the oak in the beginning of this thread with a 25 inch bar with full chisel chain with no problems. restarted the saw hot multiple times with no problems. Got back to the shop cleaned the saw all up and came home. The cylinder scoring was in the back of my mind with the low compression reading and I decided to pull the carb so I could get a good look at the intake side of the piston and the rest is history.
I don't have enough experience to tell you what caused it but i'm pretty certain I didn't go lean with the saw, but I did pull and trim the limiters so I guess it's possible and willing to take the blame. My gut tells me it's foreign object damage from either assembly or a piece from maching that came loose and the saw was like this from day one. I will never know. I do know for a small amount of money the saw will back up and running, I won't have to wait weeks for it, and I learned a **** load about the saw for the future.
thanks for all your guys input, i'm sure I will need some tips when it comes time for assembly
DAMN BINS OF DEAD STIHLS
Big_Wood
westcoast dweller
it's to hard to tell in the pics but those rings ends literally just have to touch for the end to chip. if if happened, it's so little that your gonna have to get a real close up focused or go by your judgement. all it takes is a tiny little piece of an end chipped off the do that kind of damage. if it was lean at the very minimum the side of piston 180 degrees from that point would be scored too which it isn't so i don't believe being lean had anything to do with it. maybe it was lean? what is lean? lean on AS is a 4 stroking piglet lol my saws don't 4 stroke much at all if any when fully warmed up and live through extreme use quite happily. my 461 i traded for a good saw was ported and tuned to 16.4k as a work tune! ran it that way for 175-180 tanks before i got sick of it. anyone who has ported a 461 knows damn well just how ****** and delicate the plating is compared to other saws. another possibility (even though your jug looks good) is maybe some plating flaked off from inside the upper transfer or the intake where the damage was done. close inspection might not even be able to conclude this as it could have been lose from the factory. i see this as a stihl issue not an operator issue. it is kinda hard to side with stihl after seeing all the bins of dead stihls recently though 
Big_Wood
westcoast dweller
believe it or not i actually like stihls. i just don't like the downhill slope in reliability they have taken as compared to the 460/660's. i have 2 660's and a 460 i use when i'm bored of the huskies. huskies are better for my job because they are much smoother for all day cutting. 461 to me vibrates more then 460 or a 660. well, maybe not more but definitely a different pitch of vibration that really irritates my hands and wrists after a few days.
D
Deleted member 135597
Guest
These are all very strange signs to me. Look at the pattern on top of the piston that's on the same side as the scoring. Also look at the plug difference side to side
Big_Wood
westcoast dweller
that pattern is the wash from the transfers feeding over the top of the piston. if that plug was ran on it's lean setting, your lean setting was very rich lol top of the piston does have that crispy grey lean straight gas look to it but the piston would show way more damage if either of those actually happened.i'd buff it out, new rings and run it myself but the 461 piston is $180 here in Canada.
D
Deleted member 135597
Guest
The gray might be from the 100LL. I can promise you saw was not straight gassed unless the dealer did it by mistake before I picked it up. piston was only 40 bucks new OEM.
Big_Wood
westcoast dweller
you don't need to promise me anything lol my observations are that it was not straight gassed or ran lean for long enough to hurt it without any promises. ya i heard pistons or anything is cheaper there. literally $180+tax list here and that's no joke.
D
Deleted member 135597
Guest
I don't see any table of limits in the shop manual. I'm looking for ring end gap and piston to cylinder clearance. Am I missing it or is there more literature with these limit in it?
D
Deleted member 135597
Guest
that's crazy. you should smuggle in parts to fix all those bins of dead stihls. No wonder no one fixes them and just chucks them into bins
D
Deleted member 135597
Guest
does anyone happen to have the correct part number for this coil brad is talking about?
Big_Wood
westcoast dweller
A 460/660 coil will work. Mine was the first on I installed a 660 coil on and Brad told me it don't matter if it's a 2 or 3 leg coil. Either work and he was right cause I tried both just to be sure for if/when I had to pass the info along.
D
Deleted member 135597
Guest
so if I get the part number from the IPL of a MS460 it wont be rev limited like a coil from a MS461? I want to put this in so I can use my tach to confirm the carb settings. If I see 13600 on the tach I want to know it's from the carb setting and not from the coil cutting out.
D
Deleted member 135597
Guest
So I went over everything visually in this engine multiple times. I don't see anything else damaged. The crankcase was spotless, but I flushed it out anyways. (with the crank installed) I will check the end gap of the new rings, check piston to cylinder clearance and pressure/vac test after I reassemble it. I will set the H 1.5 turns out from lightly seated and see how it does in the cut. IF its real fat, I will gradually lean it till it clears up in the cut. My guess is i'm going to end up about 1 1/8- 1 1/4 from lightly seated (where it was before I tore it down). I will leave it a little fat in the cut till the engine is fully broken in. I will also see what the compression is from the beginning and pull the muffler cover after the first couple runs to inspect the cylinder. My guess is the saw is going to live happily ever after and I will never know what the root cause of all this was. I eventually want to put an unlimited coil on it so I'm 100 percent sure of my carb settings
Just buy a used OEM one off eBay.
Khntr85
Addicted to ArboristSite
Finally we agree on one SINGLE thing.... if you ask 10 people what lean is or the correct way to tune a saw, you get ten different answers!!!!!it's to hard to tell in the pics but those rings ends literally just have to touch for the end to chip. if if happened, it's so little that your gonna have to get a real close up focused or go by your judgement. all it takes is a tiny little piece of an end chipped off the do that kind of damage. if it was lean at the very minimum the side of piston 180 degrees from that point would be scored too which it isn't so i don't believe being lean had anything to do with it. maybe it was lean? what is lean? lean on AS is a 4 stroking piglet lol my saws don't 4 stroke much at all if any when fully warmed up and live through extreme use quite happily. my 461 i traded for a good saw was ported and tuned to 16.4k as a work tune! ran it that way for 175-180 tanks before i got sick of it. anyone who has ported a 461 knows damn well just how ****** and delicate the plating is compared to other saws. another possibility (even though your jug looks good) is maybe some plating flaked off from inside the upper transfer or the intake where the damage was done. close inspection might not even be able to conclude this as it could have been lose from the factory. i see this as a stihl issue not an operator issue. it is kinda hard to side with stihl after seeing all the bins of dead stihls recently though
I would fix the stihl then SELL it imeadiatly.... then proceed to buy a husky, and a gallon of loctite and be happy.....
Big_Wood
westcoast dweller
Finally we agree on one SINGLE thing.... it you ask 10 people what lean is or the correct way to tune a saw, you get ten different answers!!!!!
I would fix the stihl then SELL it imeadiatly.... then proceed to buy a husky, and a gallon of loctite and be happy.....
funny thing is the only huskies i see losing screws are ones serviced by dealers because they are all a bunch of limp wristed culls who think 1/16 of a turn past finger tight is tight enough.
Gypo Logger
Timber Baron
You're been beveraging again, haven't you?
