Stihl MS 250, 16" bar. Had the saw now 6+ years, never had this problem until last week. Cutting dead ash and oak, and every once in a while, the chain would just bind up tight on the bar, almost like the kick back brake was on. (It wasn't) Auto oiler working well. I'd take the chain and bar off and there would be sawdust, chips jammed in the roller nose. I'd clean that out, get everything back together, and would work fine for couple tanks of gas, then happen again. Stopped at shop and guy said bar was OK. He said I was running chain to loose and or if cutting punky wood ?? I keep pretty good check on chain, and was cutting solid wood, and again, it has never happened before. Anyone have any ideas, solutions? Thanks.
I’ve had them jam when letting off on throttle coming out of a cut. Some wood and saws do it more than others. Set bottom of bar on top of log and drag chain backwards a little bit and that is often enough to free it up. Once in a while this doesn’t work and nothing else to do but take it apart and clean it. Sent from my iPhone using Tapatalk
I have a MS250 18" and had this happen a couple times too! When it happened I was cutting down by the ground, grabbing tall grass, chips building, had been cutting for a while and prematurely let off throttle. What was it, probably a combo of things, who knows??? I made it a point to keep sharp, up, tight, sure I wasn't digging potatoes and allowing chips to fill in under the saw, and give an extra second of throttle to allow saw to clean itself after the cut. Has not happened in some time now. If I recall correctly I was cutting dead ash. I wore out that bar and have a new one and it hasn't happened on this one but that is not a fair standard to judge on as I had amended my cutting habits before the bar and don't care to go back just to see if I can make troubles for myself for fun.
I have a 025.....same thing sometimes. Dragging the chain backwards usually does the trick as mentioned above.
Is chain VERY sharp and saw running at peak JDU My saw will jam up with sawdust in bar groove & nose sprocket on occasion. I notice it happens under those circumstances. Is chain stretched and is cooling off cause jam? Just a thought. nice looking load of wood BTW
Try greasing the roller nose bearing. Few shots of penetrating oil then some bar oil. Bar on my 170 does this occasionally
Cutting with the tip.? Pinched cuts? Loose chain? All can cause this. Most times for me it has been cutting with the tip and on various saws. My 250 is semi-retired.
I have an MS250 as well; going on 10 years. Great saw! You can also try hitting the sprocket with some compressed air and seeing if that dislodges anything in there. With the bar off, it'll be easy to work the sprocket both ways and get the blowgun in there at different angles. The MS250 doesn't sling a lot of oil. I do my best to run the correct tension on the chain. I keep the chain sharp as well. I'll make sure I sharpen before every cutting session....and then every few tanks of fuel through it. IIRC I'm running a Stihl yellow chain.
They make little grease guns for greaseing the roller nose. $6.58 is all it cost. I have never had that problem but I also don't have any Stihls. This one is less than $5.00 at Home Depot. Al
What chain are you running? I constantly had that problem on my Husky 550 using Husky chain. Switched to Stihl and the problem is gone,,,,unless I pinch the bar in full cut mode. The Stihl RS full chisel chain cuts a little wider kerf than Husky/ Oregon and allows the chips room to get tossed out. Also less pinching. Stretches less too. Loose chain is just as bad as too tight IMO.
Saw running good and sharp chain. Interestingly, I cut another pickup load yesterday with the saw, big bone dry dead oaks, did not have a problem at all. Thanks for the compliment on load of wood....similar one yesterday.
White Oak, Ash & Elm seem to like to clog under the chains on occasion. Have had it happen a few times even on bigger saws. Not a huge issue, I'll usually rev the saw & drag the chain to get it to clean out.
Dead and dry seems to cause this more than green for me - maybe why the tech asked if you were cutting on punky stuff. I figure it's because of the associated "sawdust" quotient that comes even with a sharp chain that's also throwing a good chip. At least in my experience, cutting dry wood produces sawdust as well as chips, which clog up the nose and need some attention. As advised, I just run the chain backwards in the log for a minute and it clears right up. On the next fill, I'll clean the bar out with a bit of fine splitter trash and drop a little bar oil on the sprocket, work it in a bit, and back to the races.
