Twofold. 1. A word of thanks to George Camp for his coaching in replacing the heater plumbing in my 70 E - Type OTC. Without his help I would not have been able to complete this very nasty job. Thanks George.
2. I have triple Weber's DCOE 45 which run great except at idle. When adjusted to 800 rpm cold the idle speed will pick up to 1600 rpm when warmed up. Any thoughts?

Gerald Brinton

Submitted by SW01-44661 on Sat, 06/11/2011 - 15:00

Andrew
My apologizes for not getting back sooner. Been out of touch for a few weeks. Your comments regarding the DCOE's are right on. When they are right they are great; however, as you put it they are "SENSITIVE".
I think my problem is warm fuel and I need to play with the float levels. The car was set up in CA and I think the problem started after I moved the car to AZ. Sea level to 3500+.
Will check out the web sites and Passini's "Tuning Tips".
Thanks again for your suggestions, I will let you know how it works out.
Gerald

w

Submitted by akblackley@roa… on Mon, 05/30/2011 - 16:41

Gerald: I do not have much experience with DCOEs on the XK engine, but I did learn a few things tuning a dual setup on an 81 Alfa Spider. These carbs are sensitive to the fuel level in the float bowl. Possibly warm fuel is expanding further up the emulsion tube than you want. Another thing: the idle circuit is extremely sensitive to the position of the throttle butterfly vis-a-vis the progression drillings above the throttle plate. I tuned the idle screws by 1/16 turn increments. Be sure that the spindles and throttle plates are all equally closed (synchronized). Also check for air leaks around the carb mountings and throttle spindles.

Here is an excellent site that discusses the DCOE in detail: http://www.tjwakeman.net/TR/WeberDCOEinfo.htm

And this: http://www.teglerizer.com/dcoe/webertune.htm

I also recommend John Passini's "Weber Carburettors: Tuning Tips and Techniques" for even more detail.

You may wish you had kept the SUs. My dual Strombergs are childs play by comparison.