Weber jetting and float needle seat size

I didn't think there were size options there. Whatever you do, use identical kits for both carbs.

As to "not your question" change the idles and drive it. Get them squared away before messing with mains. One change at a time, and if you have a wideband A/F meter, the changes are easy to see.

I'm not sure what the question is? The needle and seat are not generally something anybody ever messes with, other than to replace during a rebuild, or to set the float height. I'm not aware of any various sizes, and can't think of why there would be. There aren't any "sizes" listed on CBs parts list.

The CB jetting chart is a great place to start. With a 1915, I think 55s are going to be pretty close. The 130s may be a bit fat, but you won't know without an AF meter (unless you go WOT, pull off the road, and read a plug).

I wouldn't get carried away with the correction jet.

Stan, when I did the "cooking with idf" upgrade from CB performance,  the the kit came with different size needles and seats for the floats. So I changed them as recommended to work with the kit's "larger" venturi .
I only had moderate success with that rig and have given up on it. I have taken all that mess out and gone back to the original geometry for the carbs.

But this leaves me with a couple of different needle sizes and seats with no markings. I don't know which fits in  the original 40 idf.
When I went to Pierce manifold to buy new needles and seats (along with the jets) for the IDFs, there were lots of different sizes.   So ... which size ? - is my question.

Standard needle/seat size is 200.  I find that to be a good size for just about every motor with dual IDFs.  They offer them 150-250 in increments of 25.  While I've read that you are supposed to go to 250's when you break 200hp, I've never had the need to change needle/seat size up or down personally.

Thank you Carey!

... and I was wrong. Sorry about that, and thanks for the info, Carey!

forget the 60 idles unless you like fouled plugs

see here for discussion of weber tuning  (first few pages)

https://www.thesamba.com/vw/fo...ewtopic.php?t=293837

I'm running 57.5 idles in my 2165.

Thanks Carey, I learned something today!