Weber Questions
 

1. WHY WOULD SOMEONE PUT DIFFERENT SIZE MAIN JETS IN THE SAME SET OF WEBERS. HERE IS WHAT IS IN THE CARBS, LEFT BANK, CYL.1 JET #115, CYL. 2 & 3 JET #110. RIGHT BANK, CYL. 4 JET #140, CYL. 5 & 6 #110.
2. WHICH JET WOULD RUN RICHER #110 OR #140?
3. WHAT ARE THE DIFFERENCES. 40 IDT P 3C WEBER, 40 IDS, 40 IDA?

HHmmmm
 

Escape Wrote:

1. WHY WOULD SOMEONE PUT DIFFERENT SIZE MAIN JETS IN THE SAME SET OF WEBERS. HERE IS WHAT IS IN THE CARBS, LEFT BANK, CYL.1 JET #115, CYL. 2 & 3 JET #110. RIGHT BANK, CYL. 4 JET #140, CYL. 5 & 6 #110.

- Odd to say the least. The jets should all have the same number. That being said, it's possible that the jets have been redrilled at some point and not marked as such.

As a side note - I've read somewhere that Weber only marked their jets after checking the flow of each one - apparently oriffice (sp?) size was only one factor in flow, so redrilling to a particular size is an estimate at best. Sounds like a new set of jets would be in order.

2. WHICH JET WOULD RUN RICHER #110 OR #140?

- #140 would flow more fuel and thus run richer.

3. WHAT ARE THE DIFFERENCES. 40 IDT P 3C WEBER, 40 IDS, 40 IDA?

-Some one else can confirm, but I think:
IDT- Came on 2.0T and some 2.2T's and had different idle/bypass stuff
IDS- Used on early 911S - has an extra high speed enrichment circut
IDA- Standard Issue carbs


Hope this helps a bit

Andrew M

Mabye they wanted a purposly mismatched engine: i.e. each cylinder was calibrated for a different torque/rpm range to make a more flat torque curve.
Don't think it would work though.