Hey guys, here's the deal. I just picked up a Weber 48 IDF and I'm trying to figure out what jets to use as a base line to start my tuning. I've found lots of info on the IDA's but nothing for the IDF's. I'm builing a 13B 4 port with a half bridge and some mild exhaust porting. (Please don't flame on me for building a half bridge. I chose it for a reason) I was thinking of using 200 main fuel jets, 170 air jets, and F11 emulsion tubes with possibly a #300 float needle valve. Let me know what you guys think.

 

not sure how different the IDF is... if its similar (48mm throttle plate, venturi etc) then i'd start with IDA type jetting.

 

what i know: the jets for the IDA, IDF and DCO carbies are all the same.

what i "think" i remember: the IDA and IDF are virtually the same except, some of the IDFs have chokes and the manifold bolt patterns are reversed.

if i were you, in addition to searching, i'd probably do the following:
1. check the Australian forums for rotary-specific Weber information,
2. check with a carb-place like CB Performance and at least see if you can cross-reference combination and part numbers between the two carbs. i think they mostly deal with old VWs, but the information on the carbs themseleves is what's relevant.

all in all, i have the feeling if you use the IDA setups as a guideline, you'll be able to flesh out a solid setup for yourself and just fine tune from there.

 

From what I know, the IDA's and IDF's are pretty similar. They use the same jets, emulsion tubes, etc. I have info on how to set up a 48 IDA for a street port 13B and how to set up a 51 IDA for a full bridge 13B. I kind of picked some numbers in between those two taking into consideration the extra air volume the 51 IDA would have. I guess all I can do is try it and see how it goes.