One thing I learned quite quickly and that is, cheap parts on Amazon or Flea Bay are just that. Just don't apply to chainswas either but everything. Chinese companies with proper oversight can produce excellent products, Milwaukee cordless tools are one but no oversight equals junk.
MS250 won’t run right.
- Thread starter Jeffsaw
- Start date
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Around here MS250 owners have been known to run ethanol gas in them and then let them sit for a year or so after use with fuel still in them. That's one reason the small carburetors fail. Sometimes it will work after cleaning and sometimes you have to replace the carb.
Uh, that doesn't just apply to Chinese companies. Workers from everywhere tend to let up when the overseer is not around..
Well, I see he never showed back up. Imagine that.
MS250s are definitely known to flood, especially hot.
Been my experience over the years that if the carbs aren't properly insulated (spacer) from the jug, the heat from it causes them to hot flood. Had a Dolmar years ago that was real prone to doing that.
You got that right. How does that go... 'When the boss is away, the workers play'...
oakchop
ArboristSite Lurker
If you check this thread we're all discussing the same thing. The MS 250.
https://www.arboristsite.com/threads/stihl-ms250-bogging-at-full-throttle.308805/#post-8114902
Hot flooding is right next to this other issue.
They're very much alike. The Impulse hose.
My issue is the saw runs perfect for an hour of cutting then suddenly starts bogging at any attempt to cut. Full throttle starts to bog too. the saw is also hotter from extended high rpm (it eventually reaches this stage as with any home use saw).
After lots of troubleshooting and frustration I discovered a common issue where the impulse line or pulse hose (black hose that sits under the H and L adjustment screws between the plastic shroud. The hose gets hot and stretches. It can fall off the orange nipple its supposed to be pushed onto. when it's disconnected the exact symptom is bogging suddenly after enough runtime each time you run your saw, typically about an hour of good use. This is my exact issue.
To check it you have to take out 2 screws from the under side of your throttle or grip area, under the saw. Then remove the bushing screw on the right of the saw near the carb adjustment holes.
then you pull the saw slightly apart and look with a flash light to see if that black hose disconnected from the orange nipple that goes up through the plastic and out to the right of the carb. Connect it back gently using some curved or long needle nose pliers. it needs to be very secure. it may need to be replaced if it's falling off. I hear they fall off from excessive fatigue and stretching from heat/high rpm. chances are if it's falling off at all, it may need to be replaced because it will obviously happen again unless there's a way you can safely attach it more securely. I've heard once it falls off it COULD mean it just needs replacement. but sometimes dropping the saw or high rpm can shake it loose. In this case inspect it if you can before putting it back on. if it's still new then push it back on that nipple and try to push it far onto it. clean off the orange plastic too with alcohol if you can.
If you have to replace the hose this involves deeper disassembly.
Hope this helps some of you or gives another thing to check off.
https://www.arboristsite.com/threads/stihl-ms250-bogging-at-full-throttle.308805/#post-8114902
Hot flooding is right next to this other issue.
They're very much alike. The Impulse hose.
My issue is the saw runs perfect for an hour of cutting then suddenly starts bogging at any attempt to cut. Full throttle starts to bog too. the saw is also hotter from extended high rpm (it eventually reaches this stage as with any home use saw).
After lots of troubleshooting and frustration I discovered a common issue where the impulse line or pulse hose (black hose that sits under the H and L adjustment screws between the plastic shroud. The hose gets hot and stretches. It can fall off the orange nipple its supposed to be pushed onto. when it's disconnected the exact symptom is bogging suddenly after enough runtime each time you run your saw, typically about an hour of good use. This is my exact issue.
To check it you have to take out 2 screws from the under side of your throttle or grip area, under the saw. Then remove the bushing screw on the right of the saw near the carb adjustment holes.
then you pull the saw slightly apart and look with a flash light to see if that black hose disconnected from the orange nipple that goes up through the plastic and out to the right of the carb. Connect it back gently using some curved or long needle nose pliers. it needs to be very secure. it may need to be replaced if it's falling off. I hear they fall off from excessive fatigue and stretching from heat/high rpm. chances are if it's falling off at all, it may need to be replaced because it will obviously happen again unless there's a way you can safely attach it more securely. I've heard once it falls off it COULD mean it just needs replacement. but sometimes dropping the saw or high rpm can shake it loose. In this case inspect it if you can before putting it back on. if it's still new then push it back on that nipple and try to push it far onto it. clean off the orange plastic too with alcohol if you can.
If you have to replace the hose this involves deeper disassembly.
Hope this helps some of you or gives another thing to check off.
