Tuning Carbs Up - with or without air box

[davidvincent]

Hi all

Just wondering how you (those running carbs) go about tuning and setting your mixture and idle... do you take your air box off and set up the carb(s) or leave on?

I'm running a Weber DGAS 38 auto choke, but with a stock air box, and I 'think' it's impossible to do a proper setup whilst the air box assembly is in place - because you can't access one of the mixture screws (the one on the choke side).

So I end up removing the air cleaner assembly, doing the full setup and having it running great, but as soon as I reinstall the air box it's throws it out, presumably because of the reduced airflow. In the past I have got lucky I think, and also doing things like emulating the reduced airflow by blocking the vacuum hose with a screwdriver - but it's not very scientific, and I want to get it spot on if possible.

I have cleaned the small pipe section inside the stock air box, as it was semi-blocked, but it hasn't made a huge difference....

I didn't really want to but I'm now wondering if it would be easier to replace the stock air box with a smaller pancake style filter assembly, something with better access to the mixture screws - anyone have any thoughts on this?

Thanks in advance

David

[David Mc]

The carb has to be adjusted with all the running gear (i.e. air box) in place. Sometimes this means making special tools so that you can get at the mixture screws. An old trick I used to use is to slide a tight fitting length of rubber hose over the head of the mixture screws, re-fit the air filter, then twist the hoses to get the mixture correct. Once set, you just pull the hose off the head of the mixture screw.

[davidvincent]

The carb has to be adjusted with all the running gear (i.e. air box) in place. Sometimes this means making special tools so that you can get at the mixture screws. An old trick I used to use is to slide a tight fitting length of rubber hose over the head of the mixture screws, re-fit the air filter, then twist the hoses to get the mixture correct. Once set, you just pull the hose off the head of the mixture screw.

Cheers David, that's a cool trick - thanks