Need to borrow 4 DCOE idle jets

FIAT cars and parts wanted
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friedman
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Need to borrow 4 DCOE idle jets

Post by friedman » Wed Feb 21, 2018 4:20 pm

The air/fuel gauge shows that just off idle is way too rich,10.0-11.0 range rather than the desired 14.7. I'm using 45F9 idles so need something even leaner.

For reference, running 115 main and 170 air correctors with F11 emulsion tubes. Kind of explained why carbs ran cleaner with cold motor than hot one. So if I could borrow some idle jets leaner than 45F9s I could then figure out what to ultimately buy.




Just so you know, DCOE idle jets are totally different from idle jets in any other Weber I have ever seen.
Carl in Virginia
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Bedilion
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Re: Need to borrow 4 DCOE idle jets

Post by Bedilion » Wed Feb 21, 2018 11:04 pm

Hi Carl,
Just for fun, what size engine and what size ventures?
The 45 idle size is about the smallest in the idle zone.
Even 1300 Alfas ran 50s.
I'll discuss this with you at length, if you want to do a p/mail.
Steve B
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friedman
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Re: Need to borrow 4 DCOE idle jets

Post by friedman » Thu Feb 22, 2018 8:40 am

PM sent.
Carl in Virginia
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Re: Need to borrow 4 DCOE idle jets

Post by Bedilion » Thu Feb 22, 2018 1:50 pm

Ok, no email found, so I'll make this brief.
You may be at a rich condition at idle because you have exceeded the tuning range of the idle circuit and are
sucking unwanted (extra) fuel out of the transition circuit bores.
The throttle plates must be completely shut, and the ignition timing needs to be spot on.
The a/f idle adjust screws should be set to 1 turn out from bottoming out. No more.
Then adjust the idle volume set screws ( the ones with the 8mm lock nut) to dial in each cyl.
Sounds strange, but give it a try. You may end up going back to #50 idle jet!
I just got thru going the full 10 rounds with a Stromberg to Weber conversion on a Lotus Elan engine.
Stephen at Pierce Manifolds really helped me get thru my rich idle condition.
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