MS250 revival & carburetor part #

[Jp_over]

Friends,

Trying to revive my old MS 250 (2008) and will be adding a new carburator in the next day or so. For those who need the info, here's what I found out after a call to Zama & a call to Stihl support.

The part # on my carburater is broken down as follows:
S76A is the model #. You can also search for just "S76" because “A” [or letter] designates cosmetic changes
639A is a date code & can be disregarded

Zama recommended calling Stihl customer support for a direct replacement part # which I did.

The Stihl replacement part for the S76G carburetor is 11231200603.

I'll post back with results once I get it installed and get some work done around here. Man, I think I need an extra saw as it's too easy to put stuff off when your saw only runs on choke and kills when you hit the throttle.

Also, after I did a complete tune up (plug, filters, lines, oil pump) I had an old-timer mechanic tune it up for me but it only ran well for about a month. Also, I only run ethanol free, treated gas but Muphy can also have some say. Completely replacing the carb is my last shot on this saw to keep it going.

Just wanted to get the part # out there for folks looking for it. If this fix doesn't work I'm going to try out a similar Echo model.

 

[Czed]

https://www.google.com/search?q=sti...print-us-revc&sourceid=chrome-mobile&ie=UTF-8
Oem 32+ dollar's

 

[husqORbust]

Do yourself a favour and Kobe the Zama directly into the nearest garbage can. Then order up a walbro wt-215.

https://www.ebay.ca/itm/OEM-Walbro-...445808&hash=item4b5ff2bf8e:g:dtwAAOSwO9RbHcPt

025/250's used to come with Walbro's...then the bean counters took over.

 

[HarleyT]

From the Stihl dealer:


1123 120 0602 CARBURETOR (MS250C) $64.49


1123 120 0603 CARBURETOR (MS250) $22.67

1123 120 0604 CARBURETOR (MS210) $22.67

1123 120 0605 CARBURETOR $29.37

1123 120 0611 CARBURETOR $33.41

1123 120 0619 CARBURETOR C1Q-S90 $64.43

1123 120 0620 CARBURETOR $29.37

1123 120 0629 Carburetor $38.14

 

[HarleyT]

Here is the carb kit from Stihl:


1123 007 1060 CARBURETOR PARTS KIT $24.99

 

[HarleyT]

Here is the Walbro wt-215:


1123 120 0605

 

[Jp_over]

I appreciate all the feedback - will check out the Walbro if this Zama doesn't work out. I didn't know it (Walbro) was an option.

 

[Jp_over]

Well, brand new carb and still having the same problem. Idles great on 1/2 choke, kills when I give it throttle.

Some recent maintenance:
- fresh fuel (always used high octane ethanol free & treated)
- recent fuel filter change & fuel line
- recent new spark plug
- recent new air filter

The gasket between the carb and body was a little stiff and I wonder if this needs replacement too. Perhaps it wasn't the carb or maybe this new carb is out of adjustment? If the "high" adjustment was off I'd expect at least a little throttle but it kills just about straightaway after coming off 1/2 choke.

I'm off to watch some youtube troubleshooting for now but would appreciate some additional troubleshooting.

 

[HarleyT]

Check your impulse line.

They like to vibrate loose/off.

 

[Country bumpkin]

I’ve replaced several crank seals on this series of saws.

 

[Jp_over]

I have the model that terminates in a "tank vent" - not sure if the line is called an impulse line or a vent line but it looks good/solid.

Today, when trying to make some further carb adjustments (still not throttling up/bogging) I broke the starter rope. Prior to this I pulled the muffler and inspected the spark arrestor screen (looked fine).

Just about ready to cut my losses & pick up a new saw as I've spent quite a bit of time on this one and still haven't been able to get cutting on some overdue chores.

 

[MACHINE]

I’ve replaced several crank seals on this series of saws.

This

Sent from my SM-G930F using Tapatalk

 

[husqORbust]

The impulse line goes from the block to a nipple on the handle where the carb seals to. Can see it well with the starter removed and can fish it out with some slender needle nose pliers and a small flat blade screw driver. The impulse line drives the fuel pump with crankcase vac and pressure.

Does the saw idle it just wont rev out? No idle at all? Whats it doing precisely... set needles at 1 on the low and 1.5 on the high. Should idle and rev if its the tune

 

[Jp_over]

husqORbust,

Thanks for some good info. I just realized a couple of things.

1) My case indicates these settings for the carb:

I wonder if these setting still apply with a new Zama OEM carb?

2) The current Stihl manual shows these settings:

On the carb adjustment, now I'm really confused but at least know a bit more of the problem details. Before I made any adjustments, I could not get a decent idle. After adjusting to my case settings, I could get some idling but still bogging down with throttle. Pardon me if these questions seem ignorant but I'm learning as I go and greatly appreciate the help.

Also, I think I initially misidentified and did not check the impulse line based on your description. Is this it?

 

[HarleyT]

Yes, the other end goes to the nipple seen here.

This is the end that usuall comes off.

 

[DND 9000]

husqORbust did already give you a good starting point.

The carburetor setting depends on the carburetor which is used on your saw. According to your case picture you have not the latest carb version with "real limiter caps" on both L and H screws. The screenshot from the user`s manual is for a later version with limiters on both screws. You have a previous version with a real limiter on the H screw and a cap on the L screw which dosen`t limit the adjustment.

Attention: The settings on your case picture are only valid with seated limiters and if before the basic setting was done without caps. On most carburetors used on the MS 250 the basic setting without limiters is H=1,5 and L=1 turn open from the lightly seated position of the adjustment screw.

It would be good if you could tell us which carburetor is used on your saw. With that information the crowd here can give you the right adjustment for your carburetor.

 

[Jp_over]

Much appreciated HarleyT!

I've now correctly identified the impulse line and it was indeed detached at the nipple near the boot. I'm guessing I'll have to tear this thing down a bit to get to it.

This morning I'm going to pick up a new impulse line & a new starter cord and install them. I couldn't really see if the impulse line was damaged but it's over 11 years old and I might as well replace it while I'm in there + I have to get a new pull cord anyhow.

If I'm not sawing by mid afternoon I'll be adding a new saw to the lineup. Since it may have simply been the impulse line all along, I'll also put a bit more time into this MS 250 to see if I can salvage it as a back up.

 

[Jp_over]

DND 9000,

Thanks for clearing up the carb info. Here's the current model which I just installed: S76G carburetor / Stihl part # 1123 120 0603 (purchased locally from an authorized Stihl dealer).

 

[DND 9000]

Thank you for the information. The basic setting without caps for your C1Q-S76G would be H=1,5, L=1.

 

[HarleyT]

You need an assortment of these for chainsaw work.