# Oil coming out of muffler threads



## roccus (Jan 3, 2017)

I have some black oil coming out of my muffler on rebuilt MS260 was reading some of the threads here on it seems many say it could be from the case gasket in the oil tank area gone bad. If it was the case gasket would it hold pressure and vacuum? My saw holds pressure and vacuum perfectly. This saw has a new top end on it and I have so far only run it for maybe 15 minutes could it be that it has not seated in yet causing this? It seems to run real good but if I have the carb to rich would this pump oil out the muffler?

It is not flooding out or anything it starts easy just a few pulls when cold usually 2 pulls on full choke then 1 pull on 1/2 choke.


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## grizz55chev (Jan 3, 2017)

Run it like you stole it.


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## Full Chisel (Jan 3, 2017)

Might be tuned too rich or the metering lever in the carb is set too high.


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## roccus (Jan 3, 2017)

Well I leaned it out a bit and it seems to have helped... I know I am running a little rich as it is a new iop end and figure it best to be rich during first couple of tanks for break in. So if the crank case gasket is letting go to allow oil to push out the muffler would it hold pressure and vacuum on the leak down test?


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## roccus (Jan 3, 2017)

Another thought... this saw sat around for awhile before I got it wonder if there was oil in the crank case that is now blowing out and it just needs to run it's course to clean out? The first time I fires the saw after the rebuild I had a small puddle of oil sitting on top of the crank case under the muffler I don't seem to be getting puddles their now just more pin head sized droplets spitting out. I have now run almost a 1/2 tank gas through it since rebuild if there was excess oil in the crank how long would it take to push out?


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## pioneerguy600 (Jan 3, 2017)

Give it a couple tanks of run time, the rings should seat and the cylinder clean up. If it were the crankcase gasket it would not hold vac, possibly hold pressure after the oil tank was also pressurized. You could empty the bar oil and leave the cap off, run both vac and pressure tests then but its not likely the case gasket.


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## roccus (Jan 3, 2017)

pioneerguy600 said:


> Give it a couple tanks of run time, the rings should seat and the cylinder clean up. If it were the crankcase gasket it would not hold vac, possibly hold pressure after the oil tank was also pressurized. You could empty the bar oil and leave the cap off, run both vac and pressure tests then but its not likely the case gasket.



Thanks I really needed some good news!! I want to sell this saw but don't think I should sell it without knowing if it's ok this was a parts saw I got along with a running saw I hope to sell it to get something small and light. I will take the oil tank cover off and put some pressure to it to see what happens..... note to self when doing a pressure test in future always remove oil cap


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## Wood Doctor (Jan 3, 2017)

Sell it for something small and light? Seems to me like this MS260 is already there.

Hang onto it.


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## roccus (Jan 3, 2017)

Wood Doctor said:


> Sell it for something small and light? Seems to me like this MS260 is already there.
> 
> Hang onto it.



I have the other ms260 I will keep.. when I say small and light I am thinking something not over 12"bar in the size weight class of a mini mac


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## blsnelling (Jan 3, 2017)

If black oil continues to come out of the muffler, then the saw is likely tuned too rich.


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## Ted Jenkins (Jan 3, 2017)

I can remember two times this issue coming up recently. Most likely there is nothing wrong with the saw probably the fuel is adjusted rich which will cause at least some of the problem. If the saw is NOT under a load it can send unburned oil to the muffler because the combustion chamber is not at the ultimate temperature. There could be residual oil in the muffler and is now just getting blown out. Two tanks full of fuel and hard cutting should clear it up. Are there smaller saws than a MS 260? I always thought they were the smallest made. Thanks


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## roccus (Jan 3, 2017)

Well can I ask you all this... with the facts I have laid out with it passing leak down test and all would you consider buying a saw like this with a bit of oil spitting out the muffler and feel confident it should be ok or would you run away from it??


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## StihlNick (Jan 4, 2017)

Depends on what you were asking for it. Common folk mainly only care what it looks like anyways...


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## Little Al (Jan 4, 2017)

Are you running a rich Oil/fuel nix ? the old saws in the 25/1 & thicker mixes usually gobbed oil from the exhaust the older bikes were the same I would take off the muffler & clean the inside refit & run it.


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## Sammyp (Jan 4, 2017)

If I were selling it I'd probably break it in, then re-tune it and run hard for a tank. this should clear it out, if not then maybe you do have a problem (doesn't sound like it though or you'd have other symptoms/problems)


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## blsnelling (Jan 4, 2017)

It should not be tuned that rich even for break-in.


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## roccus (Jan 4, 2017)

Not sure if it makes any difference or not.. I use Stihl 50:1 oil mix with aviation fuel

another thing about this saw I have worked on a couple other stihl saws and when I have pulled the mufflers they have carbon build up in them which would be expected but the muffler on this saw has baked oil lining the inside of the muffler and cover so I wonder if this saw has been pushing oil out for awhile


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## pioneerguy600 (Jan 4, 2017)

I would clean that muffler out and then re tune the saw a little bit leaner each tank until it reaches the sweet spot. The oil spitting should stop by then.


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## roccus (Jan 4, 2017)

Thanks Pioneer thats what I'll do... turning low idle in leans and high speed out leans right?


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## grizz55chev (Jan 4, 2017)

Wrong.


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## Chris-PA (Jan 4, 2017)

Muffler bearing is worn - too much clearance allows oil to leak into the exhaust. Then you lose pressure on the main oil gallery and the main bearings fail. Probably should try that engine-rebuild-in-a-can stuff.


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## roccus (Jan 4, 2017)

Chris-PA said:


> Muffler bearing is worn - too much clearance allows oil to leak into the exhaust. Then you lose pressure on the main oil gallery and the main bearings fail. Probably should try that engine-rebuild-in-a-can stuff.



muffler bearings look good I sprayed them with canned steam to make sure the brake fluid would flow through them so the radiator would not over heat


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## pioneerguy600 (Jan 4, 2017)

Turning either screw in leans the fuel out, its like closing a valve. Clockwise = lean, counter clock = rich. I prefer the rough fourstroke WOT out of the cut and the clean up in the cut when the chain loads the engine. My own saws are tuned leaner than most but I can and do tune each one I am running two to three times a day. The average user does not know or have a need for on the edge tuning so the tune in and out of the cut, between 4 stroke and cleanup two stroking is very safe.


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## Sammyp (Jan 5, 2017)

clockwise leans them both out

anti clockwise makes it richer

and then the post above pops up.... sorry already answered!


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## Okie (Jan 5, 2017)

roccus said:


> Thanks Pioneer thats what I'll do... turning low idle in leans and high speed out leans right?





roccus said:


> Thanks Pioneer thats what I'll do... turning low idle in leans and high speed out leans right?



*WRONG Do as pioneerguy above says and re-search 4 stroke on the high jet adjust for now so you don't ruin your saw. And test the 4 stroke in the cut when a load is first applied.

If you are not careful you are going to ruin your new rebuild by leaning out the saw. It will happen real fast. Adjust the carb correctly take the saw to wood and run tank of gas thru it and if it's still smoking it may be burning bar oil somehow. 
You can remove the chain and leave the bar oil out (flush it out) and do a smoke test.

Pioneer guy was typing at same time as me
*


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## Little Al (Jan 5, 2017)

If you lean the Lo needle when the saw falters/hesitates on opening the throttle wind it out again & set just so the saw revs instantly without hesitation Then set HI to "burble/4stroke at full throttle out of cut( only a 2/3sec burp)& cleans up & 2stroke when cutting, go back & readjust the lo if necessary, could take several "tweeks" to get the best settings finally if required set the throttle stop screw so the saw idles at just below clutch engagement. the more you do it the more routine it will become worse case scenario; I've been known to retune at
fuel tank refills ( cold,Foggy starts & then the sun comes out) If in any doubt set a tiny bit rich, lean settings are saw wreckers


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## Okie (Jan 5, 2017)

Little Al said:


> If you lean the Lo needle when the saw falters/hesitates on opening the throttle wind it out again & set just so the saw revs instantly without hesitation* Then set HI to "burble/4stroke at full throttle out of cut( only a 2/3sec burp)& cleans up & 2stroke when cutting, go back & readjust the lo if necessary, could take several "tweeks" to get the best settings finally if required set the throttle* stop screw so the saw idles at just below clutch engagement. the more you do it the more routine it will become worse case scenario; I've been known to retune at
> fuel tank refills ( cold,Foggy starts & then the sun comes out) If in any doubt set a tiny bit rich, lean settings are saw wreckers


As indicated the saw when first placed into a loaded bar cut will 4 stroke (burp) for 2 to 3 seconds then start cutting strong running on 2 stroke.
Also when the* lo needle* is set correctly (at the slightly rich setting) the saw when you first start it *with the engine block cold* and you get the choke off and try to accelerate it may for about first 15 seconds of warm up bog if you try to piss rev (fast accelerate), just let it warm up for 15 seconds at fast idle and it will rev.

If you remove all the chain tank oil and with no chain on the saw for testing and it don't smoke you can forget about carb tuning. A check then why bar oil is getting into the engine block. Not likely for a Stihl unless maybe a crack or porous metal but I've see other type saws that use pressurized oiler tanks to start burning bar oil due to bad check valves.

If you work and piddle with chainsaws very much you might want to consider eventually getting yourself a GOOD digital tach and a infrared thermometer.

I started using a 3m type infrared thermometer about year ago in addition to a GOOD digital tach to* make sure that a chainsaw does not start overheating when into a full bar cut due to things like running lean, piston friction, air circulation, rpms' too high due to lean carb setting, MUFFLER BEARINGS as mentioned earlier, or anything that will cause a saw to overheat when in full bar cut.* The jug temp on your saw should not go above 350F and get their kinda slow or not quite get to 350F in a full bar cut. If you see it going above 350F in short period of time in a full bar loaded cut and headed towards 400F it headed for self destruct. Bring the saw back to idle or low rpms and see if it starts immediately cooling. If not cooling down very fast kill the saw and let it cool. If you test it again set to real rich on the carb and it again starts overheating remove the muffler and take a gander at the piston. If it's scored you are already SOL. (piston skirt will start expanding into jug wall and then scoring)


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## blsnelling (Jan 5, 2017)

http://www.arboristsite.com/community/threads/chainsaw-tuning-101.250802/


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## roccus (Jan 5, 2017)

Thanks so much guys for really great in depth info provided here this will for sure get me on the right track to maintaining my saws and keep them running.. I have learned so much from the peeps here the past month on saw operation workings and maintaining them to keep them in peak condition. I lie in a rural area in maine surrounded by thousands of acres of woods the person who owned the property that abuts my property owns over a mile back and has given me full permission to take all the wood I want I heat mostly wit a stove and the woods are full of hundreds of cords of wood laying on the ground just for the taking this is what 95% of my cutting is with the occasional taking a dead tree down I tend to take 8" and under size wood as no wood spitting need be done and is easy to handle I think this little ms260 will be the perfect saw for what I do.. I have 2 of these one runs perfect then the one I just rebuilt the one that runs perfect has very low hours on it and I think it is the smaller bore motor 44mm as the sticker on the handle says 49cc not 50cc also the serial number on it is 255093xxx and from what I read here only saws with serial number 262187xxx and above have the larger 44.7 motor on them I have had several other saws over the years but these are my fist stihl saws I did have an ms290 I bought used and used for a few week last fall but really did not like it for what I do it just seamed heavy and bulky to me although it seemed to have gobs of power I sold it to buy these 2 260's


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## pioneerguy600 (Jan 5, 2017)

I also became a fan of the 026 -260 saws once I figured out how to get top performance out of them. In the early days I was not really happy with the power and speed of them but they were rugged and dependable and sort of fit in with all the other Stihl saws I own and run. After some experimenting, a lot really, I have found these saws cover a wide range of cutting I do and never go to the woods without them. Hours are piling up on them and no down time on them ever.


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## Wood Doctor (Jan 5, 2017)

pioneerguy600 said:


> I also became a fan of the 026 -260 saws once I figured out how to get top performance out of them. In the early days I was not really happy with the power and speed of them but they were rugged and dependable and sort of fit in with all the other Stihl saws I own and run. After some experimenting, a lot really, I have found these saws cover a wide range of cutting I do and never go to the woods without them. Hours are piling up on them and no down time on them ever.


I buck cut a whole truckload of small branch rounds for firewood with an 026 PRO yesterday. I save these cut branches in a separate random pile as I collect firewood and they dry in the sun, ready to be cut to 18" lengths. Yes, it was cold, but the saw started on the second or third pull and ran fine, even though the bar oil was thick as pea soup. I was using a 16" B/C, full chisel, 325 pitch. One tank of fuel later I was finished. For work like this, it's my go to saw -- dependable, light, and plenty of power.

Had I gone to a second tank and kept going, I might have thinned the bar oil a little, but the engine's heat probably helped reduce the viscosity. I have a pair of these, both run well, and I doubt I will ever sell either.


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## Okie (Jan 5, 2017)

In really cold weather I sometimes go to the *Stihl winter blend bar oil in the blue jug* instead of thinning the bar oil blend in the Stihl orange jug that is like molasses when it's really cold weather.



The more people I meet, the better I like my dog.


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## roccus (Jan 5, 2017)

I never gave this much thought I usually don't cut in the winter just to cold and to much snow to truck through in the woods besides most wood I cut for stove is dead laying on the ground and it is buried under the snow so all I have is summer chain oil... hmmm it is cold out in shop and the summer oil is what I put in the saw for testing wonder if this could have something to do with oil spitting out the muffler??


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## pioneerguy600 (Jan 5, 2017)

Same up here in the Great White North, we have both summer and winter grades of bar oil. I stock up and buy it by the case, 4 one gallon jugs per case and just split up the amounts to about even numbers, most years about 3 cases of summer to 3 cases of winter. The winter grade flows very well down to as low as I want to work outside.


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## pioneerguy600 (Jan 5, 2017)

roccus said:


> I never gave this much thought I usually don't cut in the winter just to cold and to much snow to truck through in the woods besides most wood I cut for stove is dead laying on the ground and it is buried under the snow so all I have is summer chain oil... hmmm it is cold out in shop and the summer oil is what I put in the saw for testing wonder if this could have something to do with oil spitting out the muffler??



Your bar oil shouldn`t be getting into your combustion chamber at all, only way there is if that case gasket is gone. Did you ever check the through case screws that hold the two halves of the case together?


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## Okie (Jan 5, 2017)

roccus said:


> I never gave this much thought I usually don't cut in the winter just to cold and to much snow to truck through in the woods besides most wood I cut for stove is dead laying on the ground and it is buried under the snow so all I have is summer chain oil... hmmm it is cold out in shop and the summer oil is what I put in the saw for testing *wonder if this could have something to do with oil spitting out the muffler??*


*
NO. If a Stihl is smoking and burning bar oil it's going to burn thick or thin. Do the test I suggested above, remove the chain and the oil from the oil tank and see if it stops dripping oil and smoking out the muffler. You should see almost immediate results with 20 seconds after you empty the bar oil tank of running if it's burning bar oil. (that one guy said the muffler bearing seals might be bad)
I also use a thinner oil about 30W in the cheaper saws that pressurize the Bar oil tank so as they will oil better in cold weather. Some of the cheaper saws that use a pressurized oil tank recommend 30w oil all time. 
The main reason we go to thinner oil in winter is so the chain oiler is not trying to deliver molasses to the bar. I've also seen bar grooves load up (gum up with molasses wood dust) in winter when cutting frozen wood in real cold weather and the chain gets to running tighter and using a lighter oil thinned with kerosene or diesel helps, but when it's that cold I go to the house now days. Also every time you have your chain off your saws bar take a putty knife and go around the bar groove and see if it's getting gummed. (wear a leather glove and go slow or you will get a hand cut on the bar edges)If it's gummed very bad remove the bar and clean out the chain oiler hole in the bar.*


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## roccus (Jan 5, 2017)

Yea okie I will do as you suggest next time I go out to the shop for a bit have not really been out there past couple days just to cold and not enough to to do fire the wood stove I'll get out there the middle of next week and get it nice and toasty out there and putter around with it and a couple other things I want to do I want to customize a muffler for my keeper saw I ordered one of these to make a dual outlet exhaust out of it http://www.ebay.com/itm/272346684075?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT 

Pioneer geez you must cut for a living?? all the oil!!!


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## Wood Doctor (Jan 5, 2017)

Okie said:


> *NO. If a Stihl is smoking and burning bar oil it's going to burn thick or thin. Do the test I suggested above, remove the chain and the oil from the oil tank and see if it stops dripping oil and smoking out the muffler. You should see almost immediate results with 20 seconds after you empty the bar oil tank of running if it's burning bar oil. (that one guy said the muffler bearing seals might be bad)
> I also use a thinner oil about 30W in the cheaper saws that pressurize the Bar oil tank so as they will oil better in cold weather. Some of the cheaper saws that use a pressurized oil tank recommend 30w oil all time.
> The main reason we go to thinner oil in winter is so the chain oiler is not trying to deliver molasses to the bar. I've also seen bar grooves load up (gum up with molasses wood dust) in winter when cutting frozen wood in real cold weather and the chain gets to running tighter and using a lighter oil thinned with kerosene or diesel helps, but when it's that cold I go to the house now days. Also every time you have your chain off your saws bar take a putty knife and go around the bar groove and see if it's getting gummed. (wear a leather glove and go slow or you will get a hand cut on the bar edges)If it's gummed very bad remove the bar and clean out the chain oiler hole in the bar.*


Agreed. Thick bar oil in cold weather will also lock up the sprocket nose. Sawdust will mix with it and the sprocket nose will jam up as if it were welded to the bar. At that point you will have to either shut down completely or bring in a new bar to keep going. Many loggers have tried to avoid some of these problems by using a hard nose bar but even that will start smoking after awhile, burn the nose, and tighten up the chain so much that the engine cannot pull it through.

Okie, I'm surprised that you run into this in Oklahoma. It gets colder in my neck of the woods.


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## pioneerguy600 (Jan 5, 2017)

roccus said:


> Yea okie I will do as you suggest next time I go out to the shop for a bit have not really been out there past couple days just to cold and not enough to to do fire the wood stove I'll get out there the middle of next week and get it nice and toasty out there and putter around with it and a couple other things I want to do I want to customize a muffler for my keeper saw I ordered one of these to make a dual outlet exhaust out of it http://www.ebay.com/itm/272346684075?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
> 
> Pioneer geez you must cut for a living?? all the oil!!!


 We do a lot of cutting, more than most on here.


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## Okie (Jan 6, 2017)

Wood Doctor said:


> Agreed. Thick bar oil in cold weather will also lock up the sprocket nose. Sawdust will mix with it and the sprocket nose will jam up as if it were welded to the bar. At that point you will have to either shut down completely or bring in a new bar to keep going. Many loggers have tried to avoid some of these problems by using a hard nose bar but even that will start smoking after awhile, burn the nose, and tighten up the chain so much that the engine cannot pull it through.
> *Okie, I'm surprised that you run into this in Oklahoma. It gets colder in my neck of the woods.*


*


Yep, when I was younger I lived in a place with a fireplace that eat firewood and the house was uninsulated and my priority was deer season. When deer season opened the woodpile would get real weak and I would have to cut wood in the cold weather after season due to hunting priorities. (seemed to get colder and deeper snows few years ago)

Some of my thoughts:
Hunting is not a matter of life and death, It's more important than that.
The more people I meet the more I like my dog.

*


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## roccus (Jan 6, 2017)

My dog is my best friend....


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## Okie (Jan 6, 2017)

That picture of your dogs teeth reminds me I had a big hound named smiley few years ago, living in a rural area and when he run out to greet people* he would roll his lips back and show his big canine sharp teeth* which looked like he was a killer, strangers would run and jump back into their vec and/or roll up their windows real fast and leave fast or honk their horn until I came out. I would then usually call Smiley back and tie him up on a chain like he was a killer. He was just smiling and wanting some petting. No strangers would try to get past smiley's bad looking teeth. He would lick the skin off of the people that knew he was just smiling and wanting some petting.

If I was busy and did not want to talk to the strangers Smiley would keep them in their vec until they left.


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## grizz55chev (Jan 6, 2017)

I like my saws but I love my dogs.


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## roccus (Jan 6, 2017)

her name is woofiecycle and she smiles a lot her bark is what scares peeps around here


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## Okie (Jan 6, 2017)

roccus said:


> her name is woofiecycle and she smiles a lot her bark is what scares peeps around here



You need to remove that picture of woofiecycle and brush her front teeth and re-post the picture with clean teeth BEFORE PETA see's it and starts protesting cruelty to animals.
Them front teeth are dirty.


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## roccus (Jan 6, 2017)

Okie said:


> You need to remove that picture of woofiecycle and brush her front teeth and re-post the picture with clean teeth BEFORE PETA see's it and starts protesting cruelty to animals.
> Them front teeth are dirty.


[email protected]#@ peta I spoil this dog more than my wife!!! probably spend more time with her a well lol


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## Okie (Jan 7, 2017)

roccus said:


> [email protected]#@ peta I spoil this dog more than my wife!!! probably spend more time with her a well lol



PETA=People Eating Tasty Animals

Definition of PETA in this neck of the woods in the Redneck dickshernery.
and
I tell my wife that I wished she would: Just love me like my dogs does.


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## roccus (Jan 7, 2017)

Okie said:


> PETA=People Eating Tasty Animals
> 
> Definition of PETA in this neck of the woods in the Redneck dickshernery.
> and
> I tell my wife that I wished she would: Just love me like my dogs does.


lol I know what you mean when I come home my wife looks at me like oh it's just yu but my dog is happier than a pig in **** that I'm home


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## roccus (Jan 9, 2017)

Great news on this.. after the saw sat for a few days I finally got out to the shop and put another 1/2 tank of fuel in it and ran it. I backed of the high and low screws to where it is running perfect no bogging and cuts real nicely the oil coming out of the muffler has stopped so it must have been from running rich also where this saw sat for so long before I rebuilt it I had put oil on the crank to rod bearing quite heavy so there may have been access oil from the crank case coming out the muffler as well


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## Okie (Jan 9, 2017)

That's great.

Go over to pg 2 and click on the stihl video that btsnelling posted and listen to the stihl as it's cutting under load.

When he has it in the log and you hear the engine sound like it misses just little bit every once in awhile when the full load is is slightly reduced from the engine and it 4 cycles.(sputters)
4 cycle means it's running rich on fuel and this also cools the piston on a 2 cycle.)

If yours don't 4 cycle every once in awhile and it seems to be screaming in the cut, back out the H jet 1/2 turn and place the saw back in the cut and tweak it until you get the 4 cycle and it cuts good. (you *do not want the scream* smooth cut sound with not ever 4 cycling)
If the H jet is turned in too far CW the saw will seem to be running real good and screaming in the cut but the engine is running lean on fuel and Stihls will Overheat real fast and ruin the piston.
When you first start the Stihl and the engine is cold and it bogs when you hit the throttle, just let it warm up for awhile and then gently start advancing the throttle and it will warm up and go. Do not adjust it for immediate good throttle cold or it will not be correct when engine is hot Usually or sometimes.

Good Luck too ya.


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