Needle valve rubber seat. Which direction?

R

riseandrun

Member
Good morning! My rebuild kit 631893a has a rubber seat for the needle valve with a groove in one side. Does the grove go down toward the body of the jet or does it go up for the needle valve to seat against?
Thanks
R&R
 
The groove or ridge goes towards the carb body. You should see a slight tapper to the sides of the hole on the other side of the seat for the needle.

Walt Conner
 
Thanks Walt. The rubber seat doesn't go into the carb body, it fits inside of the jet and the needle valve goes through the jet. The jet screws into the body. This is the first time I've seen a carburetor like this one. It came off my Ariens snowblower with a 9.05 engine(?). I'm not even sure what brand it is. Also there is no float bowl and float
like most of my lawnmowers. I will look for a slight taper in the rubber seat.
KW
 
The center taper in the rubber seat will face the tapered area on the needle valve. This is a Tecumseh all position carb. that style of needle valve with the diaphragm works the same way it does on chainsaws, and trimmers. Vacuum pulses draw fuel into the main part of the carb, which creates a vacuum in the diaphragm chamber drawing up on the diaphragm which opens the needle valve to allow more fuel to enter that chamber, and the cycle repeats.
 
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