David Mirylees

Help! Short while ago listed a problem with the 45's on my 2 litre zetec where barrel No.3 was impossible to set an idle. Took the easy way out - thanks to my old dear - and got hold of a new pair of carbs from Gower & Lee. I now have a super idle and a very quick car at full bore but it's almost impossible to drive at any steady revs from 1200 to 3000 (which is where I spend most of my in traffic) as it misfires like hell. It is also almost impossible to adjust the idle screws as there is little discernible rev change, so they are out of the box at 2.5 turns. The balance between the carbs is showing as spot on using the crypton gauge and the butterflies are in identical positions when looking at the progression holes. There is also no hesitation when blipping the throttle so I assume the balance is OK. I also changed the ECU as the (very) old unit wouldn't recognise the latest weber thottle pot. The computer shows the throttle to be working correctly and the ECU supplier assures me that my problem is with the carbs. Unfortunately (for me) the carb bods answer is "take it on a rolling road". Not that easy and not what I expected (the carbs came jetted exactly as my originals) as I have managed for the last 36+ years on my own. Has anyone had and sorted a similar problem? What can I adjust next? Aplogies for the tome - just trying to think of everything :-( Cheers david

OK, butterfly screws are fine. Butterflies are visually sitting at rest identically. Venturi are fixed and fine. There are no air bypass adjusment screws on these old beasts - at least that appear anywhere that I have looked :-( I am thinking now that the best way forward may be to let Gower & Lee take them both and rebuild them to match. It is beginning to sound as if they are just getting old with the gremlins that lurk dormant for so long waking up!! Really frustrating when the basics of tuning cannot be applied. (I know, should have known better in the first place etc etc) Very many thanks to all that commented. cheers david

Thanks chaps - I'll get the carbs off and give the butterfly screws a good looking at etc. One thing I am unsure of - how does one adjust the airflow? I can adjust the balance and the mixture but I can see no airflow adjustment screw Ref the venturi - it (they) appear OK and were all wired for safety when I put the engine in cheers

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

You could make your own - I did and they have been magic for many years now. Also a plus is that you can replace the rubber with standard replacements from virtually anywhere. They appeared in Low Flying years ago - I am sure that Barry can find the piece if required........smile.gif

Ummm What's a roof?........

Yup - put it back to how it was :-)

Email me on david.mirylees@freeuk.com I have a 4 to 5 conversion record + drawings/pics when I did the job years ago on my standard chassis/live axled 7 and would be only too pleased to let you have a set. I would like an A4 SAE if poss.

There's a lot from Lawrence - anyone else awake out there? ...........Oh yes, watch out - Dicko's now on-line :-(

Well done! Looks a lot better and is now easier to use - thanks