Volvo Owners Club Forum - View Single Post - MOT fail for CO2

Bugjam1999 · Aug 13th, 2018, 10:23

Hi all,

I have a 1978 245 fitted with a Stromberg 175 CDUS which has failed the MOT as CO2 levels were too high. I haven't done anything to the carb yet, so a starting point is to strip it down, clean it and put it back together.

I can see from receipts from the previous owner that a new jet and needle were fitted in 2011, which equates to about 55,000 miles ago based on MOT mileages. I guess they're due for replacement then - although I'll look at them first to see if there's any obvious damage.

I also have a complete carb from another car which had 90k on it, but I have no idea how good it is or whether the jet and needle in that were ever replaced etc.

My question then - how do I/the garage go about adjusting the carb? I don't have a co2 meter so it'll have to be the garage realistically. I've seen a few threads online, most usefully this one:

https://www.volvoforums.org.uk/showthread.php?t=100472

But I'm not sure if my carb is an earlier or later type, as referred to in that thread.

It looks like this:

Any comments/help/advice? From the thread above I think if the dashpot is removed the needle can be raised up and down to adjust the mixture via a special tool, is that correct?

Thanks

Aug 13th, 2018, 10:23	#1
Bugjam1999 Master Member Last Online: Yesterday 12:00 Join Date: Nov 2012 Location: London and Cambridge	MOT fail for CO2 - adjusting a Stromberg 175 CDUS Hi all, I have a 1978 245 fitted with a Stromberg 175 CDUS which has failed the MOT as CO2 levels were too high. I haven't done anything to the carb yet, so a starting point is to strip it down, clean it and put it back together. I can see from receipts from the previous owner that a new jet and needle were fitted in 2011, which equates to about 55,000 miles ago based on MOT mileages. I guess they're due for replacement then - although I'll look at them first to see if there's any obvious damage. I also have a complete carb from another car which had 90k on it, but I have no idea how good it is or whether the jet and needle in that were ever replaced etc. My question then - how do I/the garage go about adjusting the carb? I don't have a co2 meter so it'll have to be the garage realistically. I've seen a few threads online, most usefully this one: https://www.volvoforums.org.uk/showthread.php?t=100472 But I'm not sure if my carb is an earlier or later type, as referred to in that thread. It looks like this: Any comments/help/advice? From the thread above I think if the dashpot is removed the needle can be raised up and down to adjust the mixture via a special tool, is that correct? Thanks