2 litre air cooled emission data running weber carbs

[johhny5]

Just came back from a very wet week in the new forest.
Noticed while i was down there one side of the engine was running very rich, didn't mess with it till i got it home today.
Set up is Weber 34's on a cu air-cooled with twin empi quiet pack exhaust
Found what ever i did with the mixture screw made no difference, i have mate who has a garage so put the bus on the gas analyzer,yep running very rich.Stripped down inlet manifold,carb etc as i believed i had an air leak, all looking good but found idle mixture tube on the side was not seated correctly in to the carb body.
Got running roughly,I will have to re sync the carbs tommorow .
When i have the gas analser running , what co,hydrocarbons at what idle speed am i looking for out of each exhaust pipe?
To make it as best i can
Many thanks
John

[matt-northey]

between 2.50% - 3.50% on the co2

[sarran1955]

Hello,

WHS^^, though you will be struggling to be below 4% CO at a 1000 rpm tickover.

As you have access to a gas analyser, the smoothest setup is for the engine to put up to 7 yes 7 % on hard acceleration under load, and then for the mixture to lean off once you are at steady cruising with light throttle.

What is your ignition system??

Watch the gauges in these 2 videos.

I have an analogue machine which allows me to see how things change and settle down over a cycle.

If you also have access to a rolling road, (an MOT brake tester is good) then you could look at the jetting of your carbs, depending on how you want to drive. Once you've got all the settings, mark things with tippex!!

http://www.youtube.com/watch?v=4qayyc9Z4E0" onclick="window.open(this.href);return false;

http://www.youtube.com/watch?v=dsfo5ATg ... ure=relmfu" onclick="window.open(this.href);return false;

What can I say, Aircooled is thirsty but fun!!

Cordialement,

[oorwullie]

i have no idea about webers and fancy exhausts but round my way a CU needs by law to be between 2- 4% CO2 and the HC less than 1200ppm.

perfectly attainable with standard solex carbs and stock exhaust.

[johhny5]

Many thanks for the replies, i have set the beasty up the best i can and printed out the results,
one side running 3.22 co2 and 849 hydrocarbons and the other side running 2.98 co2 and 688 hydrocarbons on tick over around 900, much better than when i first put it on the machine,well over 7 Co2,on the offending carb,diddnt bother looking at hydrocarbons smelt like it was almost neat petrol out of the exhaust
Used a small snail vac gauge with i have used on the bike carbs on my kit car to balance carbs, took out for a run seems ok
Thanks again, hope to get away again soon, when thsi rubbish weather stops