Nozzle Check Valve Stihl Part Number

[Vintage Engine Repairs]

Gents,

My carb on the Stihl 034 super is a “Zama C3A S4C 12D” and they don’t show any of the parts for this exact carb in the Stihl IPL.

I need to replace the high speed nozzle check valve, but the two Zama carbs they show in the IPL all have different part number and sizes.

This one doesn’t have any size written on it.

If anyone could shed some light and advice with what it is that would be massively appreciated!

 

[Old2stroke]

These are very simple check valves, just a small round disc held over a fuel orifice but there are a few with different dimensions on the brass body, so only the right one will work as a replacement. The walbro ones have a rubber-ish disc that changes size, leading to faulty operation and some of us just make a new disc and replace the original one (do a search on "repair nozzle check valve"). Zama ones that I have seen appear to have a fiber disc instead of the "rubber" one and probably can't be replaced but I have never seen a problem with any that have the fiber disc.

 

[DND 9000]

If you mean the valve jet for the C3A-S4C carburetor, it is Stihl no. 4119 121 5400, original Zama no. should be A007028.
https://www.ebay.com/itm/323273083917

 

[Yukon Stihl]

Post a few pic's when you have time for those of us that haven't messed with one yet...
Please...

 

[Vintage Engine Repairs]

If you mean the valve jet for the C3A-S4C carburetor, it is Stihl no. 4119 121 5400, original Zama no. should be A007028.
https://www.ebay.com/itm/323273083917

Hey mate, that comes up as jets for line trimmers that are like 30-44cc’s how did you find that PN?

 

[SteveSr]

Hey mate, that comes up as jets for line trimmers that are like 30-44cc’s how did you find that PN?

It came out of this IPL... But then there is also mentioned 1125-121-5402 in a later build.

 

[Vintage Engine Repairs]

Oh ok, yes that won’t fit, Zama says these are the carbs it fits, and that’s not one of them.

 

[SteveSr]

Oh ok, yes that won’t fit, Zama says these are the carbs it fits, and that’s not one of them.

Well, the C3A-S4C is listed in the above list. What carb do you have? There may also be a date code on the carb that would give you the vintage 80's-early 90's.

 

[Vintage Engine Repairs]

Well, the C3A-S4C is listed in the above list. What carb do you have? There may also be a date code on the carb that would give you the vintage 80's-early 90's.

I have the C3A SC4 but the carb you showed in the PDF isn’t the C3ASC4 it’s an S19. That model carb has a different nozzel check valve to the one I need for my C3ASC4

 

[Vintage Engine Repairs]

Not to go off topic but @Yukon Stihl -

take the H screw out, use a punch if you haven’t got the correct kit and tap it through. Check the service manual from the carb manufacture though, some tap through, some unscrew and some have a retainer clip which means you have to push the nozzel from the venturi back through into the metering chamber.

A light coat of oil on the new nozzel and re insert

if the nozzel doesn’t hold vacuum from the metering side then it needs to be replaced.

 

[DND 9000]

The number I posted is the valve jet that is used on the C1Q-S4C. Of course, it can be used on other models too.

 

[Vintage Engine Repairs]

Hey @DND 9000 The C1Q S4C isn’t listed on Zama website as having the same check valve as I need on my C3A S4C?

here is a list of carbs that have the same nozzel as I need, the one you mentioned isn’t listed there?

 

[DND 9000]

It is possible that they don`t have this old part anymore. I took the number from an old Stihl IPL.

 

[HarleyT]

The old price lists had some great carb info.

 

[HarleyT]

It appears in the 2019 pricelist.
4119 121 5400 VALVE NOZZLE $10.49

 

[HarleyT]

Here is the models that the jet/valve is found.

 

[Vintage Engine Repairs]

Thanks chaps for all your help. I have checked back and forth over and over all the Pn’s none interchange with Zama’s listed carbs. I’m going to try 1125 121 5408. Will report back when it arrives

 

[SteveSr]

Thanks chaps for all your help. I have checked back and forth over and over all the Pn’s none interchange with Zama’s listed carbs. I’m going to try 1125 121 5408. Will report back when it arrives

Where did you get the ...5408 number?

I may be in the same boat shortly. My 034s started misbehaving on it's last outing. All of a sudden wouldn't idle... Too lean. Then after messing with the "L" screw it started working again. I thought that there may be some crud that got into the "L" circuit causing an obstruction. When I got home I pulled the carb and really didn't find much other than the screen wasn't fully seated. So this might have been the main nozzle check valve sticking and not fully closing.

One thing that I did find was that my clear super glue welch plug sealant held up perfectly! Gasoline didn't affect it. Don't know about alcohol as I use E-free gas.

 

[DND 9000]

Might be worth checking to see if Stihl 1135 121 5401 will interchange ?

That will not interchange. This jet is for Walbro HD carburetors used on the MS 361 and Tom`s carburetor is a Zama.

Valve jet for Zama C3A-S4 = Stihl part # 1125 121 5401.

This jet is nla for a long time and was superseded to the one I mentioned above (4119 121 5400)

 

[SteveSr]

Here is the models that the jet/valve is found.
View attachment 881704

This may be misleading since Mediacat doesn't go back far enough to list the C3A-S4 carb. However, It does show the following for carbs above S19:

...5402 - Valve Jet 0.60 Technote 33.1997
...5408 - Valve Jet 0.58
...5409 - Valve Jet 0.56 High Altitude

What is also interesting is that it would seem that these have an actual metering orifice in the jet itself. These carbs had primary flow through the valve jet with secondary flow through the "H" needle. This is the beginning of the limited adjustability carbs.

The C3A-S4C carb that is in my 034S has all of the "H" circuit through the needle and there is NO metering hole in the main nozzle. This may be why valve jets from some smaller carbs also fit the C3A-S4C. BTW, mine also seems to have a long oval welch plug instead of the triangular one shown.