Carburetor O-Rings

I have an arrow pointing to the brass piece the inlet needle valve inserts in. I've had people tell me there should be an o-ring in this brass piece but the engine manuel does not show one. It appears to me the brass piece is the perfect size for the needle valve to seat perfectly without an o-ring. I do not see how an o-ring would fit here and do not see one existing, unless it is seated inside the hole somehow.

No O ring That carb uses the viton tipped float valve. The rubber tip on the float valve is the sealing media.

Perfect- I confirmed that the carb needed rebuilt and was wondering if the 22 year o-rings, body gasket and needle valve can contribute to gas getting into the crankcase oil.

Float valve leaking will allow get into the crankcase, So after replacment need to confirm that the float valve is actually sealing.

ILENGINE said:

Float valve leaking will allow get into the crankcase, So after replacment need to confirm that the float valve is actually sealing.

Click to expand...

What is the best method to confirm it is sealing?

Best option is to turn the carb upside down with the float facing up, wet the float valve and then attach something like this or similar.


You want the valve to hold around 5-7 psi. And if you order one make sure it has the psi scale and not just the bar scale.

I was putting the carb back together with the o ring kit I received and the the tiny o rings are actually round which won't fit in the holes. I believe I need the flat style to fit in the holes. Any recomendations on the best place to find a kit? I order the first kit from Amazon that matched the part number I found at Parts Tree referring to my engine spec number. The body gasket fit perfect but the slow speed jet needs the flat style o rings, not round. Also, anyone hesitant to put a $20 carb on this engine? It's on a Walker mower.

For the needle brass seat, it helps to use a Q-tip and a little baking soda to lightly polish the seat and remove any old fuel residue. This will ensure that the needle seals properly.

As for the mystery seat "O-ring", there are some carburetors out there that are designed with a Viton rubber seat that can be replaced. This carburetor is not designed that way.

As for the kit you received, they often are made for various applications, so extra parts is not unusual. By making them this way, it keeps down production costs and multiple part numbers for each specific carburetor.