View single post by DonBurns
 Posted: 02-26-2017 06:01 pm
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DonBurns

 

Joined: 09-18-2015
Location: Fullerton, California USA
Posts: 47
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Have not made much progress. I sent away for some jets to play with, including a set of 7850.7 corrector jets and 50 idle jets which is listed above under Lotus 2.0. My engine is 2.2 and I can tell you this combination did not work at all, could barely keep is running. Also noticed that my Carbtune Pro columns were barely moving no mater how I adjusted the idle screw. Tim - could you suggest a starting point idle jet for use with the 7850.7 on an engine built to Esprit S3 specs (plus big valves)?

Does someone have a Dellorto parts source in US? I sent away to the Netherlands for parts, but that means over a month between adjustments.

I finally realized I have DLHA 45 E carbs. I thought the letter was cast after the 45 so I thought mine was "no letter", but I finally noticed a very faint, as in it's not even complete, E stamped under the DLHA 45 casting, and I have 5 progression holes.

I checked my pump jets and they are 50's. In the Des Hammill book the diagram (looks like official Dellorto diagram)shows a spring between the pump jet and holder. Mine have no spring, and pictures of actual pump jet assembly in the book don't seem to show a spring. Was that a later modification?

This might be a really basic question that I probably should have understood before I started fiddling, but what is the goal for A:F mixture? I mean for optimizing for set-up and a different A:F ratio might turn out to be different for fine-tuning power and drivability. When changing jets and seeing effects is there a A:F curve we are trying to match? 13.5 at Idle and 12.5 full power? Currently I think I am rich at idle (11.8) OK during progression (13.5 - 13.0) and then maybe slightly rich at 4000. If rich at idle but good during progression, is that the reason to move from one progression tube to another?

Trying to get my head around all this - thanks for any help.