Weber carbs question......

[Martin S.]

My 2Ltr Dunnel Zetec has twin 45's fitted and every MOT I have to screw in the idle mixture screws (by which time it's running rough as ****) to get it through the emissions test, then after screw them out again. Is this normal or should I get the jetting looked at?

[Roger King]

You would normally expect acceptable emissions with the car idling happily.

 

Is your MOT station aware that amateur built cars should be tested for visible smoke only? This problem shouldn't arise.

[Jam Mad]

echo that... at my last mot the mechanics looked at it, checked it for co2 but not emissions, had a fag, and then gave me my form.

 

and it's a 1700 xflow... so not the most environmental motor car...

 

i think you should change mot garage.

 

cheers,

 

j

[Martin S.]

Hmm though emissions test was CO2 test!

[Roger King]

For a non cat car, the MOT is looking for CO (not CO2) and hydrocarbons (unburnt fuel). For a cat car they will also look at the lambda (fuel/air ratio) reading. The permissible limits vary according to vehicle age.

 

For amateur built vehicles they should test as though it is a pre 1974 (I think this is the right date) vehicle regardless of age. All this means is that they look for unacceptable levels of visible smoke.

[Sam Monoogian]

Wandering slightly off-topic, does the pre-1974 rule also apply to SVA tests. I've got a 1980 chassis that's been restored and will have to SVA it with a 1600 X-Flow of unknown age.

[Mark H]

When i MOT,d my 88 cross flow last year i was told that only factory built cars had to pass the CO2 test , not home built .does any one know if this is correct?

 

Mark smile.gif

[philwaters]

Sam, has the Chassis never been registered before? If so, then you will not need to SVA - just update the registered details with the new engine details. If not then you are right - for a newly registered car it will have to be SVA'd.

As far as I know if you can not prove the age of the engine then it is treated as new - but don't quote me.

 

Phil Waters

1600 X/flow - soon to be 2000 Zetec wink.gif

[mike ashurst]

For the MOT and emissions,

here

 

is a good place to look, I went through the agony's last Feb.

 

Mike

[hugh]

i have just passed the SVA 1650 CROSSFLOW, the following applied with regards emmissions pre 1976 engines a visual test is only required between 1976 and 1986 its tested on hydro carbons and co2 which is not very stringent (my engine with flat topped pistons and ancient carbs passed, by changing the main jets just for the test),emmision tests vary from one mot station to the other my local station used to only do a visual on my old w*******d and the same shall apply for the caterham in a few years time, my advice is find another testing station.