My Lotus/Caterham 7 with a 2.0 Zetec, running presently on a (possibly) mismatched pair of 45 DCOE's (45DCOE9 & 45DCOE16). Although the car has run well over the last 10 years since the transplant, (apart from acting as though it has a "pit-limiter" when off throttle) I have found that it is impossible to set the throttle adjustment screw as the motor "ticks-over" at 1100 plus without any throttle screw contact at all (pressure on the throttle lever will reduce the revs but it returns to 1100 or more as soon as pressure is released) with the result that it is almost impossible to tune them. (I have a strong return spring on the main lever and also on the twin cables)
I also note that the barrel on cylinder No.3 does not give any discernable "hiss" and my old crypton balancer gives a reading of 2 when all others are at 4.5, Also the idle screw, when removed, was of a black appearance as was the No, 3 plug. Regardless of this, when given some stick the beast still flies and examination of the plug immediately after a blast shows it as being relatively OK albeit a bit sooty. (can I say that?). My thoughts are that it is running rich on No.3 and I have checked the float level (15 / 8.5) and idle mixture screw a dozen times with no change.
By the bye, main jets are all 135; Idle jets are: 50F8; Emulsions are F.16.
Any helpful suggestions greatly appreciated (I have trawled back to 2001 - some interesting threads but couldn't find my particular problem) It's been a long time since I have had to play with these things...........................
Many thanks
david