nikdfish
Platinum Member
I was getting the MS 290 ready for a trip to the rental property this morning to drop a couple of small maples. I sharpened the blade, filled gas & oil tanks, cleaned & adjusted the bar and intended to crank it up to check the idle speed since it had stopped while idling during use yesterday. No luck. Could not get it to start and noticed it just felt/sounded different.
Thinking I had flooded it, I went through the flooded Stihl start ritual of removing the plug, giving it a couple of pulls, replacing it & then using the warm start settings. No luck. After going through this sequence a few times & verifying that the plug had spark, I gave up & took it back to the John Deere dealership we bought it from in September. The service desk said their Stihl guy would take a look & give me a call.
I gave them a call about 4 hours later and was told that it looked like the piston was severely scored as if from either ingestion of foreign material or running raw gas. There has only been 2 gallons of gas/oil mix run through the machine since purchase, made using the Stihl 50:1 mix oil purchased at the same time as the saw was purchased. The mix was done using 93 octane gas, one bottle of mix oil per gallon plus a tablespoon of Star Tron to deal with the alcohol in the gas (which the dealership strongly recommended) and done in a new jug purchased at the same time as the saw. I disposed of the old mix I had on hand when we brought the saw home to make sure only the Stihl mix would be used. The air filter had not been removed prior to today, just brushed off, so I can't think of how any foreign material could get into the crankcase.
I'm still waiting on them to do a tear down & evaluation, the tech had seen the piston scoring through the exhaust port after removing the muffler. The service manager said that Stihl wanted a very clear description of cause for any warranty work. I told him that if I was at fault, I would want a very clear description of what I had done to contribute to the problem & that I had followed the manual directions for operation. I didn't do any no-load WOT, even after the first half dozen tanks, only running full throttle when actually cutting.
I'll post more when I know more.
Nick
Thinking I had flooded it, I went through the flooded Stihl start ritual of removing the plug, giving it a couple of pulls, replacing it & then using the warm start settings. No luck. After going through this sequence a few times & verifying that the plug had spark, I gave up & took it back to the John Deere dealership we bought it from in September. The service desk said their Stihl guy would take a look & give me a call.
I gave them a call about 4 hours later and was told that it looked like the piston was severely scored as if from either ingestion of foreign material or running raw gas. There has only been 2 gallons of gas/oil mix run through the machine since purchase, made using the Stihl 50:1 mix oil purchased at the same time as the saw was purchased. The mix was done using 93 octane gas, one bottle of mix oil per gallon plus a tablespoon of Star Tron to deal with the alcohol in the gas (which the dealership strongly recommended) and done in a new jug purchased at the same time as the saw. I disposed of the old mix I had on hand when we brought the saw home to make sure only the Stihl mix would be used. The air filter had not been removed prior to today, just brushed off, so I can't think of how any foreign material could get into the crankcase.
I'm still waiting on them to do a tear down & evaluation, the tech had seen the piston scoring through the exhaust port after removing the muffler. The service manager said that Stihl wanted a very clear description of cause for any warranty work. I told him that if I was at fault, I would want a very clear description of what I had done to contribute to the problem & that I had followed the manual directions for operation. I didn't do any no-load WOT, even after the first half dozen tanks, only running full throttle when actually cutting.
I'll post more when I know more.
Nick
