Does anyone have pictures comparing the differences between the oem and aftermarket needle valves and seats?
Like many others at this point I imagine, I rebuilt my carb before I knew about the issues with the aftermarket needle valves and seats that come with the rebuild kits these days and am now dealing with the aftermarket ones constantly getting stuck open. I don’t even know if my carb had oem seats when I opened it up but they are long gone at this point. I’ve read that polishing up the corners of the aftermarket needle valves fixes the issue but you know what they say, a picture is worth a thousand words and I’d certainly love to see the differences between the two.
On a semi related note, are the needle valves and seats that Atkins sells oem? They are expensive at $40 but would gladly pay it if I knew they would fix my issue.

 

No pictures but one of the things you can do, besides burnishing the edges of the needles, is to take compressed air in the fuel line and use it to bounce the needles up and down with the top off and the floats hanging down. At first they may appear to stick but after awhile they start to move easier.

 

I didn't know Atkins sold the needles and seats until you mentioned it, but yeah, those do look similar OEM. I can't say if they are OEM (I'd guess not), but they definitely aren't the ones you get in most rebuild kits. Cool to see they include the little screen as well.

The easiest way to distinguish the seats from rebuilt kits is that they usually do not have a chamfer on the four little outlet ports and instead are just straight drilled holes. OEM and, by the looks of it the Atkins ones, both have these chamfers. While I don't have a photo of an aftermarket seat, here's an OEM one I put in one of my carbs a while back (yeah I might have polished it). You can see the chamfer on the port facing the camera.

 

That's good to know about the chamfer on the oem seats. I'll give a shot a polishing the corners of the needle valves and if that doesn't work pay $80 for the Atkins seats and see if that does the trick. And just to ensure to confusion, these are the corners that need to be smoothed up correct?

 

I decided to buy the needle valves and seats from Atkins to compare with the aftermarket ones I currently have. Atkins is on the left, generic rebuild kit on the right.





The needle body looks smoother and you can see the difference in machining of the seats. The Atkins seat have an extra machined lip on the bottom and it looks like the aftermarket seats are flat. I would also say that the Atkins needle goes up and down smoother and with less free play. Once I put the Atkins needle valves and seats all of my flooding issues went away. After having dealt with both now I would say if you carb doesn't have oem seats buy these and don't even bother with the seats in the rebuild kits.

 

Great photos, they really show the difference in quality.

 

Good to know. Never knew they sold qualify needle valves. Pricey for what they are. But worth every penny.