MS250 checkup

[davidwyby]

Need to replace the spur on an Ms250 and want to make sure the rest is in good health. Are there known Achilles heels on these? Not familiar with them or stihls in general.
Thanks

 

[Stevetheboatguy]

Need to replace the spur on an Ms250 and want to make sure the rest is in good health. Are there known Achilles heels on these? Not familiar with them or stihls in general.
Thanks

I seem to always be replacing fuel lines on those. They tend to rot rather quickly. Other than that they are a pretty solid machine.


Steven

 

[Chainmale]

Impulse hoses can pop off from Time to time, especially if buffers need replacing

 

[drf256]

The ground wire is a common issue also.

They are surprisingly good little clammy’s.

 

[Dustin4185]

I know where one is in a retention pond in east TN if you need parts, lol. It was way before I got into fiddling with saws and that thing wouldn’t hit a lick. We wound up cutting the tree with and axe after I threw the saw in the pond!

Every other one I’ve worked on have had one of the issues above. Fuel lines are usually the issue when someone at work brings me one and says it won’t start.

 

[Squareground3691]

Yea some line issues to , switched over to a Cannon narrow kerf bar and rim sprocket with a Stihl PS chain works well and muffler mod .

 

[irhunter]

Need to replace the spur on an Ms250 and want to make sure the rest is in good health. Are there known Achilles heels on these? Not familiar with them or stihls in general.
Thanks

Age of the saw, and estimated run time will help get better responses. Do you still have a chain catcher? These saws have the catcher molded as part of the clutch cover...right?

I agree with others about the fuel line. I do wonder if owners of these saws are not as careful about leaving gas in the saw, as they should be.

Roy

 

[Loony661]

I have an 025 and also switched it over to 3/8 Picco on a 16” bar. With full chisel it’s surprisingly quick and for its size. They also have quite a bit of grunt for their size. We used a sell a lot of the MS250’s at the dealership. They are no professional saw by any means, but they are actually darn tough and handle a lot. Our fire dept has one in our “brush truck”. My biggest advice for them is: they flood easily. If it “pops” and you pull it even 1 more time on full choke, it’s flooded...

I use mine mostly for trail clearing on the snowmobile and ATV trails. Also works well for hinge cutting trees for deer habitat. Sits most of the year for me, but glad I have it around for smaller tasks.

 

[davidwyby]

Crack in tank above fill explains leak. Sounded lean the other day…yeah 3800/15000 lean…gotta figure out how to bypass the limiter cap. no drums available locally, probably order the separate rim upgrade. Sharpened the chain on my USG, cuts good.

erratic tension is what precipitated working on it which is why I running with cover off. Seems to work ok that way. Maybe for some reason with the cover on the chain wanders over to an unworn portion of the sprocket and gets tight…
not a lot of what I assume was the chain Catcher left

 

[Loony661]

I think the polymer cases on these are susceptible to warping slightly when the bar nuts are too tight. Have you tried setting the cover on and just backing off a bit with how tight you are setting them?

Stihl makes a larger diameter stud for these because guys would over do it and pull the plastic right out with the studs... this model you can’t treat like a Pro saw when snugging the bar up.

 

[pbillyi69]

i had a friend of mine give me an old 025 that he was having issues with and he left it outside for several years with gas in it. i dumped the fuel and cleaned all of the gunk off it put some fresh fuel in and it started on the fifth pull. it needs lines and a carb kit but it runs pretty well considering

 

[qurotro]

The ZaMA carb has a accelerate pump in it

 

[davidwyby]

I cleaned and tuned it while back when I made this thread. Was lean. Came back to me because it’s hard to start, etc. Idles a few seconds and stalls. Restarts with fuel in the throat or choke. Bog when throttle applied but if you can get past that it runs full throttle and cuts.

Idle circuit plugged, impulse line, fuel line, diaphragm…? I really don’t wanna mess with it but now that I’ve touched it…

 

[thedude74]

Like others said, lines dry out. Mine did what yours did....hard, dried impulse line. The tune would wander at idle and run fine wfo. Also MS250s have a reputation developing an air leak where the cylinder and lower clam(crank case) bolt together on the right exhaust side when facing the exhaust.
If yours is leaking there you can likely see gas/oil residue at the seam.

I tried sealing the clamshell with permatex ultra grey and it leaked....Switched to Honda bond 4(gooderer)...no leak

If it were mine I'd start with replacing the fuel line, filter and impulse line.

 

[Bob95065]

I had one of these that wouldn't seal at the carb boot on the cylinder. The boot is held by the plastic baffle that slides on. Like others said replace the impulse line and I would put a boot on it too. Do a pressure/vacuum test when it's back together.

 

[davidwyby]

I had one of these that wouldn't seal at the carb boot on the cylinder. The boot is held by the plastic baffle that slides on. Like others said replace the impulse line and I would put a boot on it too. Do a pressure/vacuum test when it's back together.

Thanks amigo. I’m thinking about telling him to take it to the dealer…. I don’t mind a tuneup but if I’m gonna work on saws I have my own…

 

[thedude74]

I’m thinking about telling him to take it to the dealer….

Smart man. Good intentions often lead to fixing someone else's broken crap....forever.

 

[davidwyby]

…yet here I am… NOT a fan of this thing.

Lines are pliable and hold vac. Piston is clean. Saw Doesn’t seem old.

Messy due to cracked tank. Slightly busted air filter…saw dust into saw thru impulse into carb?

Haven’t opened the zama yet. Is there a test for accel?pump n check for squirt like a car?

Ref pics for me and the next unlucky jerk.

 

[davidwyby]

Fuel filt looks clean but has restricted feel in and out by mouth…I had a stihl filter laying around from no idea where that has no resistance. Installing that. Gonna peek behind flywheel…in carb…maybe vac test…

 

[davidwyby]

Passed press n vac. Runs. Maybe all it needed was the tab trimmed off the L. I didn’t replace anything in the carb, didn’t have gaskets. Diaphragm questionable. Still tunes a little weird on the L, never gets blubbering stalling fat. Can’t add in idle speed…so maybe still a slight lean condition.

I think I got something wonky with the AV mounts. All I did was remove and reinstall the screws but one is proud and one is deep.