dakotalawdog
ArboristSite Lurker
Howdy - I'm new here, but figure I'll be sticking around for a while, so I thought I would introduce myself. First off, the information I have found on this board in the last two weeks has been invaluable - I wish I found it a year ago. My wife and I bought a house w/ 40 acres in Southwest Wisconsin two years ago to escape the city. My job requires me to interact with some of the most foul people on the planet, so getting into the woods and firing up my saw is one chore I truly look forward to. Actually, I've found running chainsaws is kind of addicting.....
Anyways, 30 acres of our land is timber - mostly walnuts and a few oaks. I bought my first saw two years ago, a Stihl MS290 w/ 18" bar, just to clear brush and for firewood. There was a lot of downed and dead trees on the property, as no one had really done any real management in some time. For the last two winters, we have done almost all our heating with firewood from the property, which meant that 290 saw a lot of use. There were some days I dulled four chains out there cutting. Thinking back at how much I've cut, I should have probably started with something bigger.
Fast forward to a couple weeks ago, my 290 was dying when idling. Cleaned the air filter, adjusted the carb per the manual and continued cutting the 135 year old fallen oak. After 20 more minutes, she seized up. I had been thinking about picking up a bigger saw anyways, so
I bought an MS391 with a 20" bar. Definitely has more power than the 290
I'm real good with fixing guns, so I figured I'd try to rebuild the 290 and found my way here (never rebuilt an engine before). I scored the factory manual and am waiting on a new piston, so hopefully it will be up and running soon.
When I tore the 290 apart, of course, I found the piston was badly scored. Made me feel like a jerk, but live and learn. I want to make sure I do everything within my power to ensure this doesn't happen again. I realize there were things I did (or didn't do), that contributed/caused this to happen. My dealer blamed it on ethanol (without looking at it) - but I'm not 100% convinced. There are a few unanswered questions I have that I was hoping someone could clear up.
1) I did run quite a bit of E10 through the 290, which Stihl says is ok. Correct me if I am wrong, but ethanol essentially leans out your fuel/oil mixture? Anyways, the nearest place with ethanol-free fuel is only an extra 10 minute drive, so I am planning on that regardless. Does octane level matter in these engines? The only ethanol free gas I can get is premium (91) anyways, but I am curious.
2) I read the numerous threads on winter/summer operation modes and carb icing. My dealer said just to leave it in summer mode, unless it gets REALLY cold (in WI that means single digits or less). My question is this - when the air temperature drops, would the dense air not cause the engine to run leaner, which could potentially cause damage?
3) On the 290, I left the carburetor adjustment set as I got it from the dealer. It ran great on that setting in hot and cold weather for two years - until it started suddenly started dying at idle. Looking back, I see that was probably a "sign" of the impending doom, but I adjusted the carb per the manual - and it ran great for 20 minutes, until it seized. My father in law suggested running the carb richer - i.e. setting it so it bogs when I'm cutting, then backing it off a little until it doesn't. How do you guys adjust your carbs?
4) I probably did other stupid stuff, like finishing cutting with a dull chain instead of stopping and changing it - things I will not do again. Am I missing anything else? Seeing that kind of damage makes me think things were too lean and too hot, but as I said - I'm new to this, so any insight or advice is much appreciated. I know Stihl makes a great product, and the problems I had were "software" issues opposed to "hardware" so I'm hoping to fix those for the future.
Thanks again for all the insight this board has already provided. I'll be doing a lot of reading here....
My two saws (391 - right, and 290 - right, left and everywhere else)
View attachment 286678
and my destroyed piston :bang:
View attachment 286679
Anyways, 30 acres of our land is timber - mostly walnuts and a few oaks. I bought my first saw two years ago, a Stihl MS290 w/ 18" bar, just to clear brush and for firewood. There was a lot of downed and dead trees on the property, as no one had really done any real management in some time. For the last two winters, we have done almost all our heating with firewood from the property, which meant that 290 saw a lot of use. There were some days I dulled four chains out there cutting. Thinking back at how much I've cut, I should have probably started with something bigger.
Fast forward to a couple weeks ago, my 290 was dying when idling. Cleaned the air filter, adjusted the carb per the manual and continued cutting the 135 year old fallen oak. After 20 more minutes, she seized up. I had been thinking about picking up a bigger saw anyways, so
I bought an MS391 with a 20" bar. Definitely has more power than the 290
I'm real good with fixing guns, so I figured I'd try to rebuild the 290 and found my way here (never rebuilt an engine before). I scored the factory manual and am waiting on a new piston, so hopefully it will be up and running soon.When I tore the 290 apart, of course, I found the piston was badly scored. Made me feel like a jerk, but live and learn. I want to make sure I do everything within my power to ensure this doesn't happen again. I realize there were things I did (or didn't do), that contributed/caused this to happen. My dealer blamed it on ethanol (without looking at it) - but I'm not 100% convinced. There are a few unanswered questions I have that I was hoping someone could clear up.
1) I did run quite a bit of E10 through the 290, which Stihl says is ok. Correct me if I am wrong, but ethanol essentially leans out your fuel/oil mixture? Anyways, the nearest place with ethanol-free fuel is only an extra 10 minute drive, so I am planning on that regardless. Does octane level matter in these engines? The only ethanol free gas I can get is premium (91) anyways, but I am curious.
2) I read the numerous threads on winter/summer operation modes and carb icing. My dealer said just to leave it in summer mode, unless it gets REALLY cold (in WI that means single digits or less). My question is this - when the air temperature drops, would the dense air not cause the engine to run leaner, which could potentially cause damage?
3) On the 290, I left the carburetor adjustment set as I got it from the dealer. It ran great on that setting in hot and cold weather for two years - until it started suddenly started dying at idle. Looking back, I see that was probably a "sign" of the impending doom, but I adjusted the carb per the manual - and it ran great for 20 minutes, until it seized. My father in law suggested running the carb richer - i.e. setting it so it bogs when I'm cutting, then backing it off a little until it doesn't. How do you guys adjust your carbs?
4) I probably did other stupid stuff, like finishing cutting with a dull chain instead of stopping and changing it - things I will not do again. Am I missing anything else? Seeing that kind of damage makes me think things were too lean and too hot, but as I said - I'm new to this, so any insight or advice is much appreciated. I know Stihl makes a great product, and the problems I had were "software" issues opposed to "hardware" so I'm hoping to fix those for the future.
Thanks again for all the insight this board has already provided. I'll be doing a lot of reading here....
My two saws (391 - right, and 290 - right, left and everywhere else)
View attachment 286678
and my destroyed piston :bang:
View attachment 286679
