Stihl ms 250 flooding

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

richardg40

Member
Mar 11, 2013
27
My small ms250 that I like to use for cutting down smaller trees and branches keeps flooding . Its easy to start the first time but when I shut it off to refuel its won t start . I know what to do to get it going again but its a pain . im looking for a more permanent fix or what could be the problem . This saw is about 20 years old . I own a still 261 for the bigger trees .
 
When its hot you don't use the choke. When hot it might start better on the first fast idle "choke" position than in the run position. The fast idle position cracks the throttle open slightly but does not move the choke plate.
 
Also, if it has a compression release, do not use it on a hot start, only a cold start. Using the compression release when hot also tends to flood it.
 
The MS250 doesn't have a compression release. But with my saws that do have a release I use it all the time cold or hot and there's never a flooding problem from it.
 
Dirty needle seat.
Pull the needle, spray some wd40 in there, inspect end of needle, bend tab maybe...

worth a try.
 
  • Like
Reactions: richardg40
It's 20 years old, rebuild or replace the carb fuel lines and filter. Also replace the air filter.
 
That may or may not be the problem. Perhaps a carb rebuild is in order. Kits are cheap. Does your carb have both high and low needles? If you have to replace the carb, get one with both adjustment needles and learn how to adjust it. It's super easy once you learn the steps to follow.

I have several saws over 30 years old with original fuel systems. I'd have more, but ran ethanol fuel in one and had to replace carb parts, fuel lines and filter after 30 years of no issues with that saw. Anyway...
 
Last edited:
Thanks I watched a youtube video about that . This is a common problem with the 250 I believe .
It's a common problem with lots of small engines and is usually due to a dirty fuel can. It happens to almost everybody from time to time..

I would start with a needle and seat inspection. Careful, there's a few wee parts there..
 
Carbs for them are cheap...throw a new one on it and roll with it.
 
My MS250 does the same thing when starting it warm. Not hot or cold, just a troublesome spot where it's warm. Happens every few years maybe because it is not a primary saw and sits for periods of time. I have replaced the main needle (and other parts that come with a rebuild kit) and also gone with a new carb. New carb is faster but some of them don't line up to the adjustment ports on the saw body so you have to take the cover off to adjust.
 
Carbs for them are cheap...throw a new one on it and roll with it.
Imported carbs are cheap
OEM ones not so cheap
Buy a kit unless you are buying an OEM carb
 
Last edited by a moderator:
  • Like
Reactions: Newbie78
Imported carbs are cheap
OEM ones not so cheap
Buy a kit unless you are buying an OEM carb
OEM carb is what I was talking about...I dont do the aftermarket hit and miss game..seems to me the last one from the dealer was less than $50...
 
OEM carb is what I was talking about...I dont do the aftermarket hit and miss game..seems to me the last one from the dealer was less than $50...
My dad took his 250 to the dealer a few years back and it was 50 or 60 installed, cleaned, and tuned (by ear at least).

If you could use a bit more power, now would be a good time for a muffler mod. DM me or Look on youtube if interested!
 
  • Like
Reactions: Tar12
It cost a friend of mine about 180 canadian bucks for a new carb installed on his old ms250. the whole saw isn't worth that, imo.

I'd been fiddling with that saw a bit over a few years to help him keep it running. That time a quick fiddle didn't help, so he decided to just take it in, unbeknownst to me. He didn't want to impose, even though he knew I would've fixed it for him.
 
Tuned by ear (and feel) is the correct way, btw...
Tuning with a tachometer works well if you have the specs like the ones Stihl puts in their workshop manuals.

Some people don't have the ear/feel. I do but I'm open to trying other methods. Both work for me. The tach method also works when you don't have wood to cut.
 
There is no need for a tach whatsoever once you know what you are doing. It's like a file guide; a crutch, a training tool if you need it.

gizmos are everywhere. I now have a moisture meter, IR gun and a probe thermometer for my stove, for example. I use them less and less as time goes on, especially the moisture meter.
 
  • Like
Reactions: salecker
There is no need for a tach whatsoever once you know what you are doing. It's like a file guide; a crutch, a training tool if you need it.

gizmos are everywhere. I now have a moisture meter, IR gun and a probe thermometer for my stove, for example. I use them less and less as time goes on, especially the moisture meter.
Simplicity is always the best option...
No need for gizmos
experience rules