Sorry to bore you all again.

I need a duffers guide to my emissions readings at SVA

I had 2 fast idle tests

CO limit was 0.3 i was 2.24 and 1.79 respectively
HC limit was 200 i was 84 and 252 respectively
Lambda limit is 0.97-1.03 i was 0.94 and 0.95 respectively.

Natural idle test passed ok.

Can anyone suggest what i may need to do to gain better readings?

I take it thats its a carb R1?

You could look at the tubes and fish tank valve option, worked a treat for me at SVA with our blade.

Mike

Short of getting a full tune-up at a BEC friendly garage which has a Krypton tuner your choices are limited to either using something like an Gunsons Gastester or a Colortune.
I got surprisingly close with my carbs using just a Colortune and a carb sync balancer. Infact, I got close enough to pass... It helped I've got a sheddy old engine though so the limits aren't too onerous.

what kind of CAT do you have colin

lambda of less than 1 means you're running too rich. low CO and low (one one test) HC means you should have an easy job of adjusting it. If its a carbed engine, turn the idle screws in a touch until lambda is right.

My local MOT place let me use their gas tester for free.

Colin,

Do you mean idle screws or Mixture screws?

Thanks

Mixture screws, sorry. Idle mixture screws to be precise because they change the mixture at idle.