need a little IPL help on a carb

[lambs]

Hi all,
Working on a friend's MS250 and I've narrowed it down to the carb, which I've cleaned 3 times now. I'm ready to replace the carb; the saw runs great when I put a used carb from an 021 on it.

I'm looking on Amazon and eBay for a replacement for the ZAMA C1Q S76B, based on the old carb. I can only find them on Amazon, but on the bay, I can find a C1Q S76C.

Could someone please look up the Stihl part number for the S76B so I can cross reference that too?

And does anyone know if the B and C are interchangeable? I assumed there was some difference that I cannot spot in the pictures online.

Thanks!

 

[dougand3]

S76B = 1123 120 0603
Easy start version shows S75B = 1123 120 0602

 

[lambs]

Thank you Dougand3 for checking it out for me!

 

[lambs]

Other than one letter, can any one tell me the difference between the B and C units ?

 

[Chainsaw Jim]

If the fuel line barb, throttle and choke levers are in the same location then the carb will work. If it is the intellicarb style and the vent is different then use the cover from the original carb.
If the difference is the throttle plate where the linkage connects then change the entire shaft with the original.
Many carbs can easily have parts swapped to fit this saw. Basically most if not all C1Q carbs will be able to work.

 

[dougand3]

Also, Walbro WT-286 clones are a direct fit. They cost $8 shipped.

 

[lambs]

From the pics I have seen, Walbro carb H / L screws look too close together.

 

[SawTroll]

Several different carbs were used on that model, here's an IPL:

 

[lambs]

Really appreciate the help guys.

So I finally ordered a replacement Zama carb from eBay and the limiter on the H screw is only partway pushed into place.

Can I just remove the limiter or does it have to be there for some reason? I would rather leave it off if that is ok so I can tune it.

Thx

 

[dougand3]

You can remove limiter if screw has a spring to keep it snugly in place. If limiter is the "snugger", put it back on after tune.

 

[lambs]

So to do that, I need to take the carb off again after tuning it just to slip the limiter cap back on, right?

Would there be any problems with setting the H screw to the baseline setting, then placing the limiter on the H screw so it can be turned another 1/4 turn rich, and then installing the carb and tuning ?

 

[dougand3]

There isn't room to install limiter with carb box cover off? I've worked on 1 MS250 and don't recall. Maybe someone more familiar will chime in.

 

[lambs]

There isn't room to install limiter with carb box cover off? I've worked on 1 MS250 and don't recall. Maybe someone more familiar will chime in.

Well, there's a rubber sleeve over the H screw and the idle stop screw ....like a rubber boot.

I will just have to try it I guess.

 

[SteveSr]

Walbro WT-215 is another option. It is fully adjustable and was used on both 025 and MS250 early/ Non-US units. You may have to buy a new carb screw grommet but they are available.

The replacement Zamas are saw specific such that a different model is required based on engine displacement. You should be able to see this in the IPL as 210/230/250 are different displacement.