Accelerator Pump O-Rings (Carburetor Model Look-Up)

[Vintage Engine Repairs]

I’m a big fan of having an accelerator pump on a carby, but the o-rings are a known weak point.

For your reference, buy them from an o-ring supplier - it’s about 20-30 cents a piece. From Stihl / Zama, you can buy one size and not the other.

Lots of people block off the accelerator pump drillings and in some machines this works well, like the 200t, on other machines, this affects metering chamber volume and will cause strange running characteristics. I have yet to repair a machine with a worn piston or bore yet, but that does happen and is worth checking too. But having the o/rings on hand can make a quick fix for a leaking acc accelerator pump. I hope it helps.

Size One - 3x1 metric fits:



Size Two - 2.3x0.8 metric fits:

 

[EFSM]

We stock 3 different sizes: from smallest to largest 195702308 (most common on Husqvarna products), 195503010 (superceded to Z000-955-Z014-A, the most common), and 195503510 (fits some of the Stihl 4-mix/saw carbs). Replacing accelerator plunger o-rings has drastically improved the success rates of my carb rebuilds.

 

[EFSM]

I should see if I can cross reference the Zama part numbers to Walbro. Their rubber is far, far superior. I have only replaced one or two Walbro o-rings.

 

[Vintage Engine Repairs]

We stock 3 different sizes: from smallest to largest 195702308 (most common on Husqvarna products), 195503010 (superceded to Z000-955-Z014-A, the most common), and 195503510 (fits some of the Stihl 4-mix/saw carbs). Replacing accelerator plunger o-rings has drastically improved the success rates of my carb rebuilds.

Nice, I haven’t come across any 4 mix yet, that’s really handy to know. I’ll keep that in mind, thanks! My guess is 3.5mm x 1mm. Can you confirm that?

Edit: I haven’t come across any walbro carby pump issues come to think of it! Maybe I just don’t see them on carbs as frequently?

 

[EFSM]

Nice, I haven’t come across any 4 mix yet, that’s really handy to know. I’ll keep that in mind, thanks! My guess is 3.5mm x 1mm. Can you confirm that?

Edit: I haven’t come across any walbro carby pump issues come to think of it! Maybe I just don’t see them on carbs as frequently?

They are not as common but Echo uses them extensively on their top-handle saws. 3.5x1 sounds about right. They're barely bigger.

 

[pbillyi69]

We stock 3 different sizes: from smallest to largest 195702308 (most common on Husqvarna products), 195503010 (superceded to Z000-955-Z014-A, the most common), and 195503510 (fits some of the Stihl 4-mix/saw carbs). Replacing accelerator plunger o-rings has drastically improved the success rates of my carb rebuilds.

do you have the o rings for the walbro 199 carb?

 

[EFSM]

do you have the o rings for the walbro 199 carb?

I don't think we stock them. I basically don't seem them go bad.