Replacing Zama carb that has connection to purge bulb (C1Q-S84B) by a Walbro (WT-215) for MS250

[MMFoF]

I’m having big problems with my MS250 unable to idle (but I can start on high idle setting and it still cuts fine at full throttle), so I’d like to try a new carb.
It seems very difficult to get my hands on a straight OEM replacement in Australia (if anybody in Aus has tips for a homeowner like me on getting Stihl parts, please fire away), plus I’ve seen in other threads that people say the Walbro is a better option.

So if I was to replace the Zama on my MS250 which has the purge bulb and decompression valve with the wt-215, my question is - can I do this? And if so, how do I make it work and do I need to buy any other parts?

 

[Bludenz]

I’m having big problems with my MS250 unable to idle (but I can start on high idle setting and it still cuts fine at full throttle), so I’d like to try a new carb.
It seems very difficult to get my hands on a straight OEM replacement in Australia (if anybody in Aus has tips for a homeowner like me on getting Stihl parts, please fire away), plus I’ve seen in other threads that people say the Walbro is a better option.

So if I was to replace the Zama on my MS250 which has the purge bulb and decompression valve with the wt-215, my question is - can I do this? And if so, how do I make it work and do I need to buy any other parts?

Hey,
Before you even go to Stihl, have you tried resetting the carb to factory settings? Ask @ray benson for a manual and an IPL, and follow the instructions in that. If you've tried that to no avail, have you tried contacting your local Stihl dealer? Easy as a google search "Stihl dealer in *location*". You should be able to send them an email, ask for a quote and provide your carb part number or what your carb is and ask for a new one. It may be a bit pricey, but you'll have a genuine OEM one.

However, before you jump the gun and buy a brand new carb, have you taken apart your carb and cleaned it? That should be the first step, go to your local Stihl dealer, by a carb repair set (carb gasket set) and replace all the gaskets, clean out the jets, etc... YouTube has a few good tutorials on this ("Stihl carburetor clean"). If you've cleaned it and it still doesn't work, then consider replacing your carb.

If it is too expensive (I was quoted $250aud for a ms192t carb), consider trying ebay. Make sure you use ebay.com.au if you are in aus, and set you shipping post code. Search "Stihl ms250 carburetor" and filter by used. This will have a higher chance of showing an OEM one instead of some Chinese knock off. Find one that suits your price range, and check it is the same. Postage may be a little on the pricey side from the US, but would be significant cheaper than one from Stihl.

I've never worked on an MS250, but I've worked on several other ones. This is just my 2 cents and in no way am I an authorised Stihl tech. Good luck fixing the saw!

 

[ray benson]

I’m having big problems with my MS250 unable to idle (but I can start on high idle setting and it still cuts fine at full throttle), so I’d like to try a new carb.
It seems very difficult to get my hands on a straight OEM replacement in Australia (if anybody in Aus has tips for a homeowner like me on getting Stihl parts, please fire away), plus I’ve seen in other threads that people say the Walbro is a better option.

So if I was to replace the Zama on my MS250 which has the purge bulb and decompression valve with the wt-215, my question is - can I do this? And if so, how do I make it work and do I need to buy any other parts?

Check your inbox for a 250 ipl and service manual.

 

[MMFoF]

thankyou!

 

[MMFoF]

Hey,
Before you even go to Stihl, have you tried resetting the carb to factory settings? Ask @ray benson for a manual and an IPL, and follow the instructions in that. If you've tried that to no avail, have you tried contacting your local Stihl dealer? Easy as a google search "Stihl dealer in *location*". You should be able to send them an email, ask for a quote and provide your carb part number or what your carb is and ask for a new one. It may be a bit pricey, but you'll have a genuine OEM one.

However, before you jump the gun and buy a brand new carb, have you taken apart your carb and cleaned it? That should be the first step, go to your local Stihl dealer, by a carb repair set (carb gasket set) and replace all the gaskets, clean out the jets, etc... YouTube has a few good tutorials on this ("Stihl carburetor clean"). If you've cleaned it and it still doesn't work, then consider replacing your carb.

If it is too expensive (I was quoted $250aud for a ms192t carb), consider trying ebay. Make sure you use ebay.com.au if you are in aus, and set you shipping post code. Search "Stihl ms250 carburetor" and filter by used. This will have a higher chance of showing an OEM one instead of some Chinese knock off. Find one that suits your price range, and check it is the same. Postage may be a little on the pricey side from the US, but would be significant cheaper than one from Stihl.

I've never worked on an MS250, but I've worked on several other ones. This is just my 2 cents and in no way am I an authorised Stihl tech. Good luck fixing the saw!

Thanks, I'll take your advice for tracking down parts. As for have I taken apart the carb? Yes I did, but being a newbie at this, I didn't really know how to diagnose a problem. I just sprayed carb spray everywhere. I have not replaced gaskets etc (they did look OK according to some other youtube videos I had looked at). I find it hard to understand if there is a problem with gaskets how it could work so well under full throttle. I did find this thread below that seems to describe very similar symptoms (although I never went to 8 turns on the Low screw!) and it seems the final resolution was to replace the carb.
I'll also look on ebay for used OEMs - hadn't thought of that as an option

https://www.arboristsite.com/threads/stihl-messing-with-my-saw-ms250.335840/

 

[Bludenz]

Thanks, I'll take your advice for tracking down parts. As for have I taken apart the carb? Yes I did, but being a newbie at this, I didn't really know how to diagnose a problem. I just sprayed carb spray everywhere. I have not replaced gaskets etc (they did look OK according to some other youtube videos I had looked at). I find it hard to understand if there is a problem with gaskets how it could work so well under full throttle. I did find this thread below that seems to describe very similar symptoms (although I never went to 8 turns on the Low screw!) and it seems the final resolution was to replace the carb.
I'll also look on ebay for used OEMs - hadn't thought of that as an option

https://www.arboristsite.com/threads/stihl-messing-with-my-saw-ms250.335840/

Gaskets should be fine unless they are stiff to my understanding. As I stated, before you go running off to buy parts, find the part in the Manual that Ray Benson sent you that outlines how to reset the carb to factory settings. Reset to those settings and follow the start up guide and see if it will idle then.

Don't look for the exact part number on ebay, search generic terms, "Stihl ms250 parts lot" or "Stihl ms250 carburetor". If someone parts out a saw and they put up a bulk lot of parts, good chance it will have a carby in it. Chances are that the seller will be happy to separate it as well, in my experience.

Good luck trying to fix it once again