MS250 will fire, but dies a half second later, won't stay running

[kspakland]

Trying to fix a friend's MS250.
It will fire after the choke primes it, raise the lever to the start notch, pull the rope and it runs for about a half second, but won't stay running.
Should I suspect the impulse line, or maybe look elsewhere?
Thanks guys ....

 

[HarleyT]

Look closely at the fuel line for cracks.

 

[brandonstc6]

Look closely at the fuel line for cracks.

Then go through the carb after checking the fuel line. The impulse line is kinda hard to get to. You have to take the handle loose and lift it up to take it off.


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[bigmoose]

Pull the muffler and look at the piston

 

[kspakland]

The saw has incredible compression, it's a workout to pull the rope to start it, so I think the piston should be okay.
I will double check it anyway.
It would be nice if all it needs is a new fuel line and/or carb cleaning.
I dread to think what a dang Stihl dealer is going to charge me for a carb kit ..... lately it seems their prices on everything have jumped dramatically.
Thanks for the suggestions, guys .........

 

[blueberrymuzik]

I ran onto a MS250 with these same symptoms a couple of years back- the muffler was clogged.

 

[farmer steve]

The saw has incredible compression, it's a workout to pull the rope to start it, so I think the piston should be okay.
I will double check it anyway.
It would be nice if all it needs is a new fuel line and/or carb cleaning.
I dread to think what a dang Stihl dealer is going to charge me for a carb kit ..... lately it seems their prices on everything have jumped dramatically.
Thanks for the suggestions, guys .........

i think when i had carb issues 2/3 years ago on mine a new carb was less than $30 from Stihl. had issues with my 023 yesterday and replaced plug/air filter and reset the carb back to factory specs and then it ran fine. old plug looked good and i had blown off the old filter before i went out to saw.

 

[Den69RS96]

My Stihl dealer will not sell rebuild kits for the carbs. I had to buy a new one for my 250. They are around 25-30 bucks. My saw did the same thing. I cleaned the carb a couple of time in the past, but after the 3rd time, my saw would no longer start. Since my dealer is a little far away, I bought a new fuel line and impulse hose as well. My saw didn't need them, but since I already had it apart to check them I just replaced them. I kept the original as backups. Fired right up with the new carb.

 

[Gugi47]

I ran onto a MS250 with these same symptoms a couple of years back- the muffler was clogged.

Me to.
With a hand torch heat the muffler all to cherry red and blow it with air.
Clean the screen with wire brash.
Problem solve.
That happens when use to much oil or the wrong oil.. That's just for future referents to your friend.

 

[Rockjock]

My Stihl dealer will not sell rebuild kits for the carbs. I had to buy a new one for my 250. They are around 25-30 bucks. My saw did the same thing. I cleaned the carb a couple of time in the past, but after the 3rd time, my saw would no longer start. Since my dealer is a little far away, I bought a new fuel line and impulse hose as well. My saw didn't need them, but since I already had it apart to check them I just replaced them. I kept the original as backups. Fired right up with the new carb.

Find a new dealer. Problem fixed.

 

[Den69RS96]

I have found another dealer a couple towns over that I'll give a shot next time I need a carb kit. The dealer I normally use told me a carb kit was around 18 bucks plus tax. A new carb was around 25. For the small difference in price, I wanted the new carb anyway. This dealer stopped ordering kits because all the jerk customers would come back in and complain that the kit didn't fix their saw or trimmer etc. They got tired of that and just ordered new carbs.

 

[kspakland]

I was searching on ebay and see a lot of Walbro carbs and fuel lines from China.
The price is in the budget, but I am concerned about the quality.
Has anybody here had experience with those parts ?

 

[HarleyT]

Get one at your Stihl dealer, they are cheap.

 

[Rx7man]

doesn't Definitive Dave have kits for them?

I have a hard time believing that so many carbs are in fact faulty that are getting replaced.. I have NEVER bought a new carb, and only rarely bought a rebuild kit. The key is using the right solvents to get rid of the gunk and microfine wire to clean orifices.
I agree.. check fuel line and impulse line first, and intake boot

 

[kspakland]

HarleyT: Thanks, but you have not had to deal with the two sorta local, (50 miles each way) Stihl dealers here, they are beyond greedy and charge way more than retail for everything they sell, plus they have a bad attitude like the customers are wasting their precious time.
I would prefer to deal online with anybody else but them.

 

[HarleyT]

If you can get a brand new OEM carb for @ $22, why in the hell wouldn't you?

 

[HarleyT]

Well I'll get you one and mail it to you, Shipping would be $2.80

 

[kspakland]

I would suspect the reason so many carbs get replaced is due to the crappy gas with ethanol that is being forced upon us.
That and the crud and sediment that comes out of the tanks at the gas station is amazing.
I use a lot of 5 gallon cans here for my trucks and generators, and the lids are kept tight so no foreign matter can enter, yet I find a lot of chunks of crud in them that can only be coming from the gas station tanks.

 

[kspakland]

The dealers here would charge 40 bucks plus tax for that $22 carb.
I would gladly paypal you the $22 plus $2.80 shipping !!!!!!!

 

[kspakland]

I braved the cold outside just now and took a close look at the saw, the muffler is clear, not plugged, and the fuel line is still nice and flexible and appears to have no cracks in it.
But it can't hurt to replace the lines on a saw with the age on it this saw has.