David Mirylees

My 1988 chassis Caterham has the problem of gaining +10 degrees on the water temp guage whenever the headlights or the cooling fan (etc) are operated.

I have tried fitting a solid state voltage stabiliser (from my Europa) to see if it improved anything but it made no difference.

Any suggestions as to the reason for the initial problem and a subsequent cure would be very much appreciated.

Cheers

david

Just to cover the whole sorry sequence of affairs........

Gower & Lee refuse to change the carbs (turns out they are 4 progression hole versions and not the 5's) their advice is that they have many 2.0 zetecs running on the 4 holes trouble free and I should take the car to a rolling road. Now done that (another £450) and the engine is as bad as ever. Goes like a train when floored but impossible to drive in traffic. Gower & Lee said they would get "recompense from Weber" if I got the rolling road bods to furnish a report. Course the RR bods were/are not keen to do this and state that they can probably get the car sorted if they had it for a week (yeah, and another £1200!!) but no promises.

Apparently (source - Weber) the 4 hole versions were developed on behalf of GM but due to pretty well exactly the problems I have been getting, they developed the 5 hole version for the 2.0 Zetec.

State of affairs now is when I took the car back to the RR a bright spark at the took the 50F9 slow running jets and opened up the side hole to appx 2mm and, although not perfect, the low end has improved with no popping and backfiring. (luckily they did this for nought as it was embarrassing that they could not improve the car previously on the two days they had previously played with it).

Moral #1 If it ain't impossibly broke - don't fix it.

Moral #2 Only buy bits like this from the "right" people.

This has been an expensive exercise, I can't throw any more cash at it and the sellers really aren't interested in helping. All very annoying as I have been playing with twin carbs for more than 35 years. I really should have been able to fit a new pair of carbs and found - at the least - smooth basic running characteristics, just as I have in the past.

EOF

Unfortunately personally cannot recommend Gower & Lee. They told me one of my 45's had the most bent spindle they had ever seen. I ordered a new pair of 45's for my 2.0 Zetec. and have been trying for 3 months to get the things to run. It appears that they supplied a 4 progression hole version (developed for the GM/Vauxhall) whereas Webcon said I they should have been a 5 progression hole version (developed specifically for the 2.0 Zetec)

The car pops and bangs at any steady revs and all Gower & Lee will do is state "take it to a rolling road".

(and yes, I have checked and changed all the electrical bits - just in case)

Hope you get sorted.

cheers

david

The whole fiasco has cost so much now I think I would have been better paying a bit more and going for the complete injection system :-)

Unfortunately rebuilding the original carbs was not a good idea as they had been problematic from the word go. Although supplied as a pair, one was a 45DCOE9 and the other a 45DCOE16 and even the choke levers worked in opposite directions (need a choke sometimes to start in mid winter as the car - until now - was my everyday transport). Initially, after a blat, the things would cut-out having run out of fuel but I sourced that to massively out of adjustment float levels. Gower & Lee told me that they were scrap and that they had never seen such a twisted spindle on my rear carb!!!!!

Really thought buying new was the most simple and effective way forward - I am also hearing (now!!) that some chaps have horror stories with these new Spanish built units (my ECU supplier told me that he had a new pair on a customers engine that one barrel wouldn't work - eventually found, after removing some blanking plug, that there was swarf completely blocking a passageway....................

Ho hummmmm what do they say about hindsight................

david

Paul Turner told me that he had a similar (but opposite) problem and different emulsion tubes made the difference. I have asked Gower & Lee to let me have a trial of the recommended F4's (I have F16's fitted)

I have tried many, many times over the last few weeks to contact James Whiting on the phone - I keep getting an answering machine - anyway, have actually left a message today so may get a response (James actually supplied the original, now scrap. carbs!!!)

Thanks all for your help - I'll post the results and hopefully the cure if and when it happens (for the sake of future searches).

I have now been 7-less for the longest time in more than 30 years - what a ******** up :-(

cheers

david

The new carbs have the 5 progression holes - actually the missing band is probably just when the butterflies clear these.

Coil wires OK - I crimped them with great care to ensure all was OK..........

Looks like the rolling road is the only option

david

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

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.