Original jet sizes

[JohnFol]

Hi all, car in for MOT today and there is a question about emissions.

Car is a '79 2l spider with the 34 DAT and I had used this as a guide when replacing jets / tubes (from another post on here)

• Primary Idle   0.7 instead of 0.5 standard
• Primary  Main  130 instead of 120 standard,  kept standard F30 Emulsion Tube,  Air Corrector Cap 160 instead of 170
• Secondary Idle 1.0 instead of 0.8 standard  (doesn't seem to be anything available between 0.8 and 1.0)
• Secondary Main 155 instead of 140 standard, kept standard F30 Emulsion Tube,  Air Corrector Cap 225 instead of 240

I know the car runs rich, so I'd like to go back to "original spec" and just want to check the "instead of" values are correct for my car, i.e. primary idle from factory was 0.5
Any thoughts welcome

[Nigel]

John,
According to my notes your original figures are correct.

For MOT purposes, make sure the tester is applying the correct values
for year of car, it makes a huge difference.

Nigel

[JohnFol]

Can't recall the exact, but something like 4 and mine is 10
Thanks for confirming

[WestonE]

Hi john

With CO levels like that check the float needle is closing properly and the float is at the right height. If you are running an external electric pump it could be pushing the valve open causing flooding. If so an inline pressure valve set at 3psi is needed.

There are various guides on how to set the float level arround.

I hope this helps.

Eric   

[capriblu]

The revised jetting will have minimal effect on CO levels at idle.  As you know my car runs this jetting and CO levels are generally somewhere around 2.5 at idle.  As Eric suggests the issue probably stems from something more fundamental.  As well as float height setting have you checked the idle mixture screw condition and adjustment?