Stihl MS181 starting & running problems

[Rich J]

Hi,

 

just found this forum and hoping I can get some help.

 

I’ve had my Stihl for 7 years and in the last couple of years it’s started to run poorly. It bogs down when I pull the accelerator trigger and I’ve had the carb cleaned, replaced the air filter, fuel filter, spark plug, fuel line but no change. A couple of weeks ago I asked my local garden machinery shop and they suggested taking off the adjustment caps on the H & L carb adjusters which I did, and with a bit of tweaking of the screws the saw then ran ok and I thought result! However I tried to start the saw today and initially it did run on tick over but wouldn’t speed up, and after randomly turning the H & L adjustment screws it now doesn’t start at all!!

 

is there a standard start setting for the H & L adjusters without the caps i.e. screw fully clockwise and then 2 turns counter clockwise that will at least get the saw started? Or am I looking at getting a new carb?

 

thanks

[spudulike]

Assuming this is the 1139 machine with the limiters removed, from the screws fully in (don't over tighten), the H screw should be 1 1/2 turns out and the L screw 1 turn out. There have been a few incarnations of this machine but these settings should get it going assuming there is nothing seriously wrong with it.

[openspaceman]

1 hour ago, spudulike said:

Assuming this is the 1139 machine with the limiters removed, from the screws fully in (don't over tighten), the H screw should be 1 1/2 turns out and the L screw 1 turn out. There have been a few incarnations of this machine but these settings should get it going assuming there is nothing seriously wrong with it.

I had a similar sort of problem with a ms181C which @bmp01 diagnosed as an air  leak past the accelerator pump (as I recall), he plugged the thing as a least cost repair and the saw was returned to its owner, still running last I saw it.

[Trailoftears]

Bit of a negative thought tbh,but depending on the useage you've had over 7 years plus the cost to replace/repair ratio assuming you may have to pay for a main dealer diag./repair.Assuming you've had good value out of it.May be worth buying a new unit and keeping all the known good parts off it?These small budget homeowner saws tend not to be Stihl's finest tech/durable items to be brutally honest.If you've had 7 odd years of decent graft out of one of these units-you've done ok frankly.

[Trailoftears]

From past experience I find these cheaper stihl homeowner/farmer chainsaws are a lottery really.Bought a 170-horrid little saw,,bought a 180c-still serving me well after doing things it was never designed for 12 years later.

Bought a 250 some years ago-went back to the dealer 4 times under warranty-they couldnt fix it/I couldnt fix it-worst saw I've ever bought.On the other hand I've rarely had issues with their pro saws-or indeed the 'vintage' old farmer saws they used to sell-the older 0 prefix saws seem bulletproof.

[Stere]

Some new versions  have come out so both thoose models are now superseeded

 

MS 162 Benzin-Kettensäge online kaufen | STIHL

WWW.STIHL.DE

---

STIHL MS 162 ist eine zuverlässige Motorsäge für Einsteiger: kompakt ✓ komfortabel ✓ vielseitig ✓ ➤ Jetzt kaufen!

 

Stihl MS 172 chainsaw | GRUBE.EU

WWW.GRUBE.EU

 

 

 

 

 

[Gav73]

Might be an odd one, but have you changed the 2 stroke oil you use? I had a 170 - great little saw - and to say it was a “diva” would be an understatement. It would only run when I used stihl HP ultra. Anything else in it (even normal stihl 2 stroke) and it would cut out/not start etc

[bmp01]

16 hours ago, openspaceman said:

I had a similar sort of problem with a ms181C which @bmp01 diagnosed as an air  leak past the accelerator pump (as I recall), he plugged the thing as a least cost repair and the saw was returned to its owner, still running last I saw it.

Yep.

Accelerator pump circuit is a good thing as new - nice throttle response. Sadly it doesnt stay that way forever and has a lot to answer for in terms of irregular or intermitant poor running. At the end of the day its a bit of unnecessary baggage to help with emissions legislations. But just deleting it doesnt always work because the rest of the carb is setup to work along side a functioning accelerator pump.

 

Accelerator pumps didnt always exist though; it is possible to get decent throttle response with out one.

 

As Spud says best make sure nothing else is wrong with saw before going down this rabbit hole.

 

[peatff]

I had one of these doing similar and all it needed was the metering lever lifting a bit.

[spudulike]

I think the OP has pissed off in to the distance!