husqORbust
ArboristSite Operative
Hey, I bought a second hand ms250 that at this point makes me want to rip my hair out...
The saw has it's original bar and chain on it, and the bar is mint. The plastics are mint, and the saw is visually in pretty good condition. I'm using those two indicators that the saw has some pretty low hours on it.
Before going to look at it I asked if it would hold its own weight on the starter cord and he responded with "150psi compression" or something pretty decent numbers wise. So... I figured I'll go take a look at the saw.
When I showed up, the saw looked pretty mint. Akin to a looking at a second hand car that had just been freshly detailed. I checked the gas tank... mint fuel in it, not a spec of dirt. Air cleaner was mint. Saw held it's own weight for awhile before slowly slipping through the compression and down to the next one...definitely didn't just yo-yo itself through the cord. I figured that ought to be pretty good.
Muffler was cool to the touch...so it didn't seem like it was sitting there hot waiting for some unsuspecting victim to show up and have it fire up half way thru the first pull...
After my preliminary inspections he asked if I wanted to hear it run and I go sure....he takes it from me and chokes it and pulls the cord twice. Puts it to high idle and yanks er twice more and it's flashed right up he clicked the throttle and it kicked down and idled perfectly. He revved er up a few times and handed me the saw.
I roll it all over the place, rev it up myself a few times, shut it off, flashes back up with half a pull, let it sit there and idle for a bit then roll it all over the place again and rev it up. Checked the oiler...works mint.
I'm thinking great...this saw should do exactly what I need it for. Go from cold start, flash right up in 5 pulls or less, buck down some trail blow down or buck up some wood to have a weekend fire or camping fire wood. Hand him some cash and go on my marry way.
I get home and couldn't help myself but to yard the muffler off and look at the piston and sleeve. Looks mint. The screen is mint too. I slide the muffler back on, torque it down and think I just made a great purchase.
2 weeks later I fire it in the back of my truck, go out and have a fire, and every so often it'd just stall out as soon as I finished a cut. Would fire right back up. I think that was kind of odd but oh well....carry on.
Couple weeks later next outing it would have slight bogging issue off idle and if I didn't run the trigger right to get it up to revs it would stall out....then it would stall out after a cut. Or just die randomly sitting there idling. Not really happy with the saw at this point but whatever, fire it back into the case and carry on.
Couple weeks later next outing I'd fire it up, and it would die as soon as I touched the throttle. So after about 5 start ups and dies I would finally get it to be able to rev up to full throttle...make some cuts, if I didn't keep it revving it would just die out...as soon as it died I'd have to mess with it for awhile getting it running...a series of pulling the trigger for a bunch of times killing it then I'd end up being able to get it back up to full throttle. Sometimes the saw will just run on high idle then die immediately when touching the throttle. Or, it'll die by itself after a few seconds of high idle.
Now...at this point... I'm done with this thing, my buddy's Husq has year old fuel mix in it, fires up 5th pull or less every time and is bucking wood down within 30 seconds of pulling it out of the case, cuts everything, runs mint, never messes around with it, and gets used about as frequently as mine sitting unused for weeks at a time... hands me the saw, I do whatever I need to do with it... clearly not a user issue. There's something wrong with my piece of crap Stihl.
I'm not a small engines tech, and before about 72 hours ago, I had no idea how a small engines carb worked, what an impulse line was, or had any knowledge of a chainsaw engine operation other than when I pull the cord I want it to start right now and buck trees in 30 seconds or less without ever messing with it...lol...wishful thinking.
Things I've checked, and where I'm at with the saw...
- Every time I went out, I mixed up a liter of 94 octane no ethanol and 50:1 with Stihl oil. Whatever didn't go in the saw that trip, got dumped out. Fresh mix every time. This is not an old fuel issue.
- I checked the plug...looked acceptable... replaced it anyways. Didn't solve any of my problems.
- Fuel filter is mint
- Tank breather is mint
- Air filter was probably not the issue...cleaned it anyways... it definitely isn't the issue now, and it being freshly cleaned solved none of my problems.
time to get a little more adventurous with this pile...
Yard the carb off. Stick a dab of grease in the impulse hole and pull the cord. Blows a hole clean through the grease. Going to say the impulse line is not my issue. Holding off on replacing...
I blow into the fuel line plugging the other end... holds lung pressure. I suck...holds lung vacuum...the fuel line is also nice and rubbery-pliabe-like and looks pretty mint and has no signs of decay. Holding off on replacing.
The intake rubber to block looks nice and premium too...Holding off on replacing that on a whim.
Now I'm thinking the problem is in the carb.............................................lol. Start googling to get the why for and how to on small engine carbs. Ya, this probably isn't so bad. Tear the carb apart...The pump diaphragm looked mint. The metering diaphragm felt mint too. All the ports looked free of obstruction...took a small rubber hose and placed them everywhere I could to blow and suck and they're all clear. I put the carb back together and try to simulate the way the metering diaphragm should work with lung pressure and all that..ya she's all good to go. The mechanical nature of the carb checks out.
Now, I'm googling the why for and how to for tuning the carb...thinkin maybe the carb tune is my issue and these limiter caps gotta go. Bin the limiter caps. Thread the needles all the way down and back the low needle out 1/4 turn and the high 3/4 turn..(I know now this isn't right, but bear with it)
Fire the carb back in the hole... the carb gasket is looking suspect at this point because half the stud hole is torn now but looks good otherwise as far as sealing the throat bore of the carb...figure should be good enough for a test hit on the new carb needle settings.
Take it outside, choke it yank the chord like it owes me money and it pops. Decent...move to half choke and yank the chord again like it still owes me money and the saw flashes right up into high idle and I click the throttle and it comes off high idle and for a second it idled then died...my crash course on google for carb tuning tells me the low speed is too lean...so I crank it out a quarter turn, put the saw back on high idle and yank the cord like it owes someone else money and I'm the enforcer...flashed up into high idle, I clicked er off high idle and it sat there and purred like it hasn't in a long time. I hit the throttle and it thought about revving up and dies. Flash it back up, turn low screw in till it wants to die then I thread it out till it wants to die then put it somewhere in the middle where it idled best...probably right around 1 1/4 turns out from seated. Turned down the idle screw so the chain stopped moving. Hit the throttle and it was like ya baby, super crisp and fast off idle response...would rev up till it ran out of fuel on the top end. Time to work on the high speed.
So I dial out the high speed and get it to the point where it's revving to the moon, and continue to dial er out til she's "4 stroking" and I'm happy with that. Maybe a tickle rich. Probably right around 1 1/2 to 1 3/4 turns out at this point.
She's idling like never before(except for the day I bought it... it was idling perfect...but I tuned it now, so it's idling better hahaha), roll tests mint, super crisp off idle response, revs up right now.....I haven't thrown a single part at this thing, and now she's running perfect. What the heck did even do other than take it apart a bit and put it back together.
Fire it back in the case thinking done deal...not even sure what I did but I'll take it. Later that day go grab my bud and we head er for the mountains. Pull it out of the case and it flashes up in 3 pulls or less, revs up a couple times, a little sloppy on the throttle response, dies out on idle... Now it's doing exactly what it was doing before.... Barely get it to rev up, dies, barely get it to idle, dies immediately off high idle. What a piece of junk. Good thing my buddy brought the Husq
The saw has it's original bar and chain on it, and the bar is mint. The plastics are mint, and the saw is visually in pretty good condition. I'm using those two indicators that the saw has some pretty low hours on it.
Before going to look at it I asked if it would hold its own weight on the starter cord and he responded with "150psi compression" or something pretty decent numbers wise. So... I figured I'll go take a look at the saw.
When I showed up, the saw looked pretty mint. Akin to a looking at a second hand car that had just been freshly detailed. I checked the gas tank... mint fuel in it, not a spec of dirt. Air cleaner was mint. Saw held it's own weight for awhile before slowly slipping through the compression and down to the next one...definitely didn't just yo-yo itself through the cord. I figured that ought to be pretty good.
Muffler was cool to the touch...so it didn't seem like it was sitting there hot waiting for some unsuspecting victim to show up and have it fire up half way thru the first pull...
After my preliminary inspections he asked if I wanted to hear it run and I go sure....he takes it from me and chokes it and pulls the cord twice. Puts it to high idle and yanks er twice more and it's flashed right up he clicked the throttle and it kicked down and idled perfectly. He revved er up a few times and handed me the saw.
I roll it all over the place, rev it up myself a few times, shut it off, flashes back up with half a pull, let it sit there and idle for a bit then roll it all over the place again and rev it up. Checked the oiler...works mint.
I'm thinking great...this saw should do exactly what I need it for. Go from cold start, flash right up in 5 pulls or less, buck down some trail blow down or buck up some wood to have a weekend fire or camping fire wood. Hand him some cash and go on my marry way.
I get home and couldn't help myself but to yard the muffler off and look at the piston and sleeve. Looks mint. The screen is mint too. I slide the muffler back on, torque it down and think I just made a great purchase.
2 weeks later I fire it in the back of my truck, go out and have a fire, and every so often it'd just stall out as soon as I finished a cut. Would fire right back up. I think that was kind of odd but oh well....carry on.
Couple weeks later next outing it would have slight bogging issue off idle and if I didn't run the trigger right to get it up to revs it would stall out....then it would stall out after a cut. Or just die randomly sitting there idling. Not really happy with the saw at this point but whatever, fire it back into the case and carry on.
Couple weeks later next outing I'd fire it up, and it would die as soon as I touched the throttle. So after about 5 start ups and dies I would finally get it to be able to rev up to full throttle...make some cuts, if I didn't keep it revving it would just die out...as soon as it died I'd have to mess with it for awhile getting it running...a series of pulling the trigger for a bunch of times killing it then I'd end up being able to get it back up to full throttle. Sometimes the saw will just run on high idle then die immediately when touching the throttle. Or, it'll die by itself after a few seconds of high idle.
Now...at this point... I'm done with this thing, my buddy's Husq has year old fuel mix in it, fires up 5th pull or less every time and is bucking wood down within 30 seconds of pulling it out of the case, cuts everything, runs mint, never messes around with it, and gets used about as frequently as mine sitting unused for weeks at a time... hands me the saw, I do whatever I need to do with it... clearly not a user issue. There's something wrong with my piece of crap Stihl.
I'm not a small engines tech, and before about 72 hours ago, I had no idea how a small engines carb worked, what an impulse line was, or had any knowledge of a chainsaw engine operation other than when I pull the cord I want it to start right now and buck trees in 30 seconds or less without ever messing with it...lol...wishful thinking.
Things I've checked, and where I'm at with the saw...
- Every time I went out, I mixed up a liter of 94 octane no ethanol and 50:1 with Stihl oil. Whatever didn't go in the saw that trip, got dumped out. Fresh mix every time. This is not an old fuel issue.
- I checked the plug...looked acceptable... replaced it anyways. Didn't solve any of my problems.
- Fuel filter is mint
- Tank breather is mint
- Air filter was probably not the issue...cleaned it anyways... it definitely isn't the issue now, and it being freshly cleaned solved none of my problems.
time to get a little more adventurous with this pile...
Yard the carb off. Stick a dab of grease in the impulse hole and pull the cord. Blows a hole clean through the grease. Going to say the impulse line is not my issue. Holding off on replacing...
I blow into the fuel line plugging the other end... holds lung pressure. I suck...holds lung vacuum...the fuel line is also nice and rubbery-pliabe-like and looks pretty mint and has no signs of decay. Holding off on replacing.
The intake rubber to block looks nice and premium too...Holding off on replacing that on a whim.
Now I'm thinking the problem is in the carb.............................................lol. Start googling to get the why for and how to on small engine carbs. Ya, this probably isn't so bad. Tear the carb apart...The pump diaphragm looked mint. The metering diaphragm felt mint too. All the ports looked free of obstruction...took a small rubber hose and placed them everywhere I could to blow and suck and they're all clear. I put the carb back together and try to simulate the way the metering diaphragm should work with lung pressure and all that..ya she's all good to go. The mechanical nature of the carb checks out.
Now, I'm googling the why for and how to for tuning the carb...thinkin maybe the carb tune is my issue and these limiter caps gotta go. Bin the limiter caps. Thread the needles all the way down and back the low needle out 1/4 turn and the high 3/4 turn..(I know now this isn't right, but bear with it)
Fire the carb back in the hole... the carb gasket is looking suspect at this point because half the stud hole is torn now but looks good otherwise as far as sealing the throat bore of the carb...figure should be good enough for a test hit on the new carb needle settings.
Take it outside, choke it yank the chord like it owes me money and it pops. Decent...move to half choke and yank the chord again like it still owes me money and the saw flashes right up into high idle and I click the throttle and it comes off high idle and for a second it idled then died...my crash course on google for carb tuning tells me the low speed is too lean...so I crank it out a quarter turn, put the saw back on high idle and yank the cord like it owes someone else money and I'm the enforcer...flashed up into high idle, I clicked er off high idle and it sat there and purred like it hasn't in a long time. I hit the throttle and it thought about revving up and dies. Flash it back up, turn low screw in till it wants to die then I thread it out till it wants to die then put it somewhere in the middle where it idled best...probably right around 1 1/4 turns out from seated. Turned down the idle screw so the chain stopped moving. Hit the throttle and it was like ya baby, super crisp and fast off idle response...would rev up till it ran out of fuel on the top end. Time to work on the high speed.
So I dial out the high speed and get it to the point where it's revving to the moon, and continue to dial er out til she's "4 stroking" and I'm happy with that. Maybe a tickle rich. Probably right around 1 1/2 to 1 3/4 turns out at this point.
She's idling like never before(except for the day I bought it... it was idling perfect...but I tuned it now, so it's idling better hahaha), roll tests mint, super crisp off idle response, revs up right now.....I haven't thrown a single part at this thing, and now she's running perfect. What the heck did even do other than take it apart a bit and put it back together.
Fire it back in the case thinking done deal...not even sure what I did but I'll take it. Later that day go grab my bud and we head er for the mountains. Pull it out of the case and it flashes up in 3 pulls or less, revs up a couple times, a little sloppy on the throttle response, dies out on idle... Now it's doing exactly what it was doing before.... Barely get it to rev up, dies, barely get it to idle, dies immediately off high idle. What a piece of junk. Good thing my buddy brought the Husq
