Stihl ms250-hard to pull start rope

[Robin Rowley]

I've got an old Stihl ms250 that has gradually gotten about impossible to start. I just broke the second pull rope out of it--it feels like it's got too much compression. Once started it runs and cuts great. I took the muffler off and looked at the piston, it doesn't appear to have much carbon built up on it. Anybody got any ideas what the problem could be??

 

[DND 9000]

Is your saw flooded? This could be a reason for it. Did you check that?

 

[RED-85-Z51]

250s were pretty notorious for being hard to pull. Ill get 5 or 6 a year that people feel like there is a problem...but its just a 250 being an ass. I drop start all saws so its nothing out of the ordinary to me but bench starting, they pull notably harder. Use a good rope.

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[HarleyT]

Did you look for carbon on the top of the piston?
Also, is the pull rope as long as it should be?

 

[Robin Rowley]

No not flooded. Pull rope correct length. Negligible carbon on piston. I drop start my Echo all the time. This Stihl requires about 4 times the effort and didn’t used to be this tough. Carbon buildup on the head? Carb leaking gas into cylinder? (I’m not very sharp on how small 2 stroke carbs work). I hate to scrap the thing, it still cuts great but I’m tired of replacing pull ropes!

 

[rupedoggy]

Bring it over and I can trade for a nice easy starting ms170

 

[dmb2613]

No not flooded. Pull rope correct length. Negligible carbon on piston. I drop start my Echo all the time. This Stihl requires about 4 times the effort and didn’t used to be this tough. Carbon buildup on the head? Carb leaking gas into cylinder? (I’m not very sharp on how small 2 stroke carbs work). I hate to scrap the thing, it still cuts great but I’m tired of replacing pull ropes!

Father Time , I see that you are 67 , the 250s are very hard to start if you dont give it an all out pull to start with. I bet you have had it pull the handle through your fingers. That will make you a little tinder pulling it. I am 65 and get one of the young bucks at work to start the 250s.

 

[irhunter]

How does it roll over without the plug? It, of course, should be smooth and effortless. Maybe something is binding up?

 

[RED-85-Z51]

Father Time , I see that you are 67 , the 250s are very hard to start if you dont give it an all out pull to start with. I bet you have had it pull the handle through your fingers. That will make you a little tinder pulling it. I am 65 and get one of the young bucks at work to start the 250s.

Yep. Most of the ms250 complaints are 65+. It takes a confident hard pull. A hint of hesitation and it will make you pay.

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[Maintenance supervisor]

I've got one on a park and the guys have broken 2 ropes and th recoil , but i think the carb is weeping a little gas .

 

[PV Hiker]

I've got an old Stihl ms250 that has gradually gotten about impossible to start. I just broke the second pull rope out of it--it feels like it's got too much compression. Once started it runs and cuts great. I took the muffler off and looked at the piston, it doesn't appear to have much carbon built up on it. Anybody got any ideas what the problem could be??

A few things since you said it is gradually getting worse. Carb could have a leakie needle seat valve putting extra fuel when you try to start.

Might try adjust the low needle, check coil gap and slightly open sparkplug gap.

Get you a trunk monkey to come out and rip it for you.

 

[SteveSr]

Did you look for carbon on the top of the piston?
Also, is the pull rope as long as it should be?

Also is the pull rope OEM? Aftermarket is typically smaller diameter for the same advertised size. If the diameter is too small it will bind in the pulley.

 

[Robin Rowley]

Thanks for the input, guys. Especially all the old age remarks . I think I might invest in a $15 eBay carb since I can afford it and maybe try to pick up a used trunk monkey there too in case the carb doesn’t help.

 

[sundance]

I'm the same age and have the same issue. I'm also not ready to concede that I've failed physically.
I'm going to try a new Walbro WT-215 carb to replace the Zama and see if that helps. Mine acts like it hydrolocks just sitting.
Note that my dealer assures me I've become too weak.
If the new carb doesn't help it I'll probably be looking to sell to one of the young bucks who can apparently start them effortlessly.

 

[grön ek]

Thanks for the input, guys. Especially all the old age remarks . I think I might invest in a $15 eBay carb since I can afford it and maybe try to pick up a used trunk monkey there too in case the carb doesn’t help.

Some people get lucky with $15 carbs, but I've had nothing but bad luck. I just bought a proline for $50 which worked perfectly out of the box. Have you checked the woodruff key? I know it's unlikely, but it happens occasionally.

 

[irhunter]

How about this zero-cost carb test. Empty saw of gas, get it started by whatever means necessary, let it idle through the gas in the line and carb. Now that the saw is purged of gas, how does it roll over?

 

[HarleyT]

Some people get lucky with $15 carbs, but I've had nothing but bad luck. I just bought a proline for $50 which worked perfectly out of the box. Have you checked the woodruff key? I know it's unlikely, but it happens occasionally.

Same goes with hookers..

 

[farmer steve]

How does it roll over without the plug? It, of course, should be smooth and effortless. Maybe something is binding up?

Try this Robin. It will tell you if there are other issues.

 

[purdyite]

I had a 291 that would rip the handle out of my hand on starting. It seemed that the timing was advanced just enough that it would spark before TDC and try to reverse the rotation. A new coil fixed it. Just a thought. But I can't see where a coil would "get worse"; the 291 did it from the first time I started it. (It wasn't new; was a pawn shop find.)

 

[Robin Rowley]

I was leaning towards the hydrolock theory but have taken the carb out, removed the plug, pulled it through several times and replaced plug. Still hard as hell to pull. So that would disprove hydrolock, right??