Mixture Settings

Post by **wehey** » 11 Aug 2006, 10:02

I have a 1980 2L Aircooled.

To get through the MOT we had to weaken the mixture but now im worried it could be running hot and damaging the engine.

Im gonna take it to a garage and ask to borrow their emmissions machine.

What would i be looking for on the readout to ensure its running about right.

Thanks

Post by **HarryMann** » 11 Aug 2006, 12:33

The mixture you reset to pass the emissions will only affect the idle and maybe pickup from idle - if that even.
Unless you changed the main jets, or emulsion tubes then when cruising or under full load, I wouldn't think things have changed.

If you get popping back through the exhaust on the overrun (when decelerating, or rolling down a hill on a closed throttle) or an irregular idle (hunting) then you've gone too weak on the idle screw.

I think I'm right in saying that, and that you're far from alone in believing that the mixture screw affects much more than low speed idle on a fixed jet type carb.