Ms250 advice

[Brent Nowell]

Guess the word got out I like to play with saws, Neighbor's friend dropped off an ms250 that looks well used but well taken care of. He wants it to “run better”

I figure I’ll start it up and see if there are any real running issues at all, I just got it last night so I have t started it yet. I have a hunting trip here today so I probably won’t get around to it till tomorrow.

Any issues with these models I should watch out for?
I’m a husky guy myself, so I know nothing about this model. I figure I’ll check the usual make sure there are no air leaks and then break out the tach and do a tune on it. Clean the screen etc... of throttle response is really poor I’ll have to take a look at the carb and see if pop off pressure is an issue or possibly an accelerator pump issue. Maybe it doesn’t have one

Any tips would be appreciated

 

[Joseph Huckabaa]

I have an MS250 that I’ve been using for about 6 years. I’m definitely not a pro but I like mine. The only complaint I have is the air filter assembly. The air filter after some time doesn’t seal to the carb adapter very well. They’re fine when new but after getting hot they don’t fit well. The only other problems I have had were operator error like leaving fuel in it for too long and having to get a new carburetor.


Joseph Huckabaa

 

[drf255]

I just modded one yesterday.

Very good light little saw.

Open the muffler up into the roof or floor of the baffle inside the port entry. Open the front exit. Pry open the front deflector gills.

Then you will have to pull the pin in the side of the carb that limits H screw opening. You will need more fuel.

With the above mods you will have a different saw. Just spend some time making certain you get all the metal shavings out of the muffler.

 

[Brent Nowell]

I just modded one yesterday.

Very good light little saw.

Open the muffler up into the roof or floor of the baffle inside the port entry. Open the front exit. Pry open the front deflector gills.

Then you will have to pull the pin in the side of the carb that limits H screw opening. You will need more fuel.

With the above mods you will have a different saw. Just spend some time making certain you get all the metal shavings out of the muffler.

Thanks I’ll do that if I don’t find any major problems

 

[Brent Nowell]

Ohhhh massive air leak on the boot.

Idle adjustment all the way in lol, low idle adjustment was out 4 turns maybe a little more to compensate lol. It actually idled normal.

Put the low screw one turn out and it was screaming. Sprayed some carb cleaner near the boot and it stalled.
Looks like an easy fix. Neat little saw layout from what I can see

 

[Justin Taylor]

Muffler mod

 

[holeycow]

I saw two of those "not running very good" ms250's a while back on two separate occasions.

They just needed carb adjustments. Pulled caps, adjusted, done. 10 minutes each.

They come tuned for ****

Delayed post by me. Your case is obviously different.

 

[holeycow]

PS, I thought those seemed like pretty handy little saws. Very light and maneuverable with decent power and throttle response

 

[Brent Nowell]

There was no vac leak I am just an idiot sometimes...

Ripped it all apart to the boot and couldn’t see anything wrong, the plastic plate was blocking the rest. Didn’t want to pull the cylinder until I did a vac test, and it passed with flying colours. Put it all back together again and fired it up, lmao I was adjusting the fricken idle screw in all those turns... must have cause the limiters were still on the carb and there’s no way I could have turned in the low that many

It runs fine.

I’ll throw a muff mod on it tomorrow as per drf255’s advise and retune.
Shaved off limiters with a knife..

The design of this saw seems to be as dumb as me! Gotta pull the cylinder to remove a boot?

The 550 and the 372 can be done with cylinder on. The 550 would require some very interesting screw drivers however. 372 is a bit of a pain.

Can’t seem to get the plastic plug for the lower anti vibe grommet in all the way, 1/8 sticking out. Is there a trick or is the lower one supposed to be like that?

Thanks all for the help!