Weber Carb Tuning Saga

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Doverhay
Posts: 264
Joined: Thu Sep 27, 2018 6:43 pm
Location: TA66NN

Weber Carb Tuning Saga

Post by Doverhay » Wed Feb 02, 2022 5:17 pm

After playing around with at least 100 combinations of different idle, air and main jet I decided to change the emulsion tubes, that’s the tube that holds the main and air jet for the higher engine rev range. Currently fitted were a pair of F2 emulsion tubes. I had a pair of F16 tubes that I’ve never thought about fitting until now. To these I fitted 140 main jets and 190 air jets, the very first jet combination I tried when I initially fitted the carb. Why did I consider playing around with the furling again, well I recently changed the exhaust system by removing the expansion boxes and the balance pipe which did change the fuelling requirement, so it was back to playing around with jet combination’s again. This is when I noticed the F16 emulsion tubes, so fitted the above combination and took the car for a test drive, it was fantastic, the Triking grin had returned.
So the jetting I now use in the Weber DCOE45 is: 50f9 idle jets, f16 emulsion tube with 140 main and 190 air jets.

Oily
Posts: 25
Joined: Mon Oct 01, 2018 6:09 pm
Location: Jersey

Re: Weber Carb Tuning Saga

Post by Oily » Thu Feb 03, 2022 4:17 pm

I shall give this a try - many thanks! Since fitiing mine I’ve struggled to get the mixture correct. Dry sooty plugs which fail after about an hour’s driving. Present set up is 50F9 idle, 120 main, F2 emulsion, and curiously enough,185 air corrector on the left (the side that fails first) and 190 on the right.

Doverhay
Posts: 264
Joined: Thu Sep 27, 2018 6:43 pm
Location: TA66NN

Re: Weber Carb Tuning Saga

Post by Doverhay » Thu Feb 03, 2022 8:21 pm

120 on the main jet is a bit small. The best I got the engine to run with the f2 tubes is with 55f8 idle and 145 mains with 175 air jets but it still hesitated when using the throttle but ran reasonably well. Let me know how you get on.

Doverhay
Posts: 264
Joined: Thu Sep 27, 2018 6:43 pm
Location: TA66NN

Re: Weber Carb Tuning Saga

Post by Doverhay » Fri Aug 05, 2022 8:45 pm

Just an update on the Weber carb tuning. I have been playing around with the ignition timing, according to the Weber tuners ignition timing is vital. The need for more advancement of ignition at the low rpm range is necessary; however, this is difficult when you only have a few options on the ZDG3 electronic ignition system. If you advance the standard single plug setting you’re going to have far to much at the top rpm.
I’ve now taken a different approach, setting 6 on the system is for dual plug systems and starts at 5 degree before tdc and tops out at 28 degrees top rpm, but if you use this setting and advance it 6 degrees you now have 11 degrees to start with and 34 degrees at the top end.
Using this ignition setting along with the F16 emulsion tubes, 50f9 idle jets, 135 main jets with 175 air jets I’m now getting very close to optimum of the carb set up😎

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