Getting CO 2 emmissions down ?

[Martin Hall]

Hi
Just got back from a controle technique
After spending over a month and several rolls of Mig wire later The car only failed on exessive co2 emissions
What is the procedure for reducing this ?
I have searched back on the archives and there seems to be mention of turning the mixture screw right in then out 1.5 turns Only trouble is my carb does not have a mixture screw only slow running adjustment screw
Would it be an idea to replace the carb with a older one with mixture screw or is there another method I have checked the air filter etc
The car is running sweet as a nut otherwise
By the way the car is a 4 clan R1123
Thanks in anticipation
Martin

 

[Martin Hall]

By the way the failure reading was 10.2%

 

[Steve Hennessey]

What carb do you have? There must be a mixture screw - it may be hiding under some dirt or hidden under a small plastic bung. If you have the downdraught Solex look under the float bowl somewhere. Is your airfilter clean?

 

[Chiller]

Look hire

It should be one of these, hope I helped.
Sorry for my English.

 

[Martin Hall]

Hi
The carb is a Zenith 32if
Which came from R5 1108 cc 1984 phase 1 car It has no mixture screw I can see Thought I found it but it is just a hole
I have found a original carb that should go on this engine It looks like the second one in the pictures and is a 28if I am going to fit that and am going to get a co2 measureing machine Gunsons do a Gas tester for around 100 pounds To set it up properly for the retest

Any ideas what the co2 limit is in the UK I expect it is similiar in France

 

[Steve Hennessey]

If you've got a 32IF from the Mk1 R5 that is very good news. Don't fit the 28IF (it won't fit the manifold anyway) as they are rubbish. I've got a 32IF on my R4 and I can tell you that there is definitely a mixture screw. It's well hidden away and you'll need a very thin screwdriver to adjust it. If there is a hole without a screw it is possible that the screw is missing. The CO2 is anything between .5 to 3% but I always adjust to get the tickover smooth and not lumpy.

 

[Martin Hall]

Hi Steve
Thanks for you replys
So you would leave a 32if carb on the car even though its a small engine R1123 845cc I think It does run very well as is But of course I have to get those co2 emmisions down
I have another 32if carb on a engine with a banana shaped cylinder head This carb does have a screw on it It is in a hole

By the way my R5 Laurete R1397 passed at 3.5% co2 so I guess if I get it down to that it should be OK
The trouble is with the french system is you have to make a booking for a retest They wont just check it is OK and You have to book a couple of weeks ahead to get a appointment So I want to get it right before I go back
Martin

 

[Steve Hennessey]

I believe the smaller engines did have the 32IF fitted. When they made the GTL they put the 28IF on instead of a decent carb. Why don't you just take the screw out of the other carb and see if it will fit into your 'blank hole'? One of the common causes for the screw coming out is a perished 'o' ring - the screw needs to be held firmly in place for obvious reasons.

 

[Martin Hall]

Well eventually found the mixture screw under a metal plate that had to be drilled out and with my new Gunsons emission tester got the reading down to .58%
Took the car back for the retest and passed straight away Although the car was running like a bag of **** So when I got home re adjusted the mixture to give around 3.00% The high limit on a 1985 car in France is 4.5% anyway
Readjutsed the timing again to the clemtine way it was miles out
Took the car out for a test drive and is running sweet as a nut now
But after stopping in the village for a bagette the car wouldnt start

Battery flat !!
The alternator wasnt charing I dont think it ever had been as the charge light has never been on So put a replacement alternator on and changed the bottom heater hose that was leaking a bit now the car is running fine I guess you are going to get teething problems on a car that has been laid up for a number of years