Mixture screws

[markmark2]

Hi all, bit confused here....left hand carb, mixture screw turns and turns and doesn't bottom, I know that this isn't correct (will repair at later date) but when using colour tune have the perfect blue flame so maybe I got lucky when it decided not to move any more giving me the correct mixture setting. However the right hand carb turns about 3 1/2 turns from top to bottom and stops at the top and bottom but cannot get a blue flame. Is there an explanation for this to enable me to get the correct mixture? Any help appreciated. Cheers Mark

[tractorjames]

Hi all, bit confused here....left hand carb, mixture screw turns and turns and doesn't bottom, I know that this isn't correct (will repair at later date) but when using colour tune have the perfect blue flame so maybe I got lucky when it decided not to move any more giving me the correct mixture setting. However the right hand carb turns about 3 1/2 turns from top to bottom and stops at the top and bottom but cannot get a blue flame. Is there an explanation for this to enable me to get the correct mixture? Any help appreciated. Cheers Mark

Sounds to me like the needle has unwound off the bottom of the adjuster. Mine did it and it was just a matter of taking the damper out and pushing the needle upwards to start the thread back off.

As for your second issue, I had similar problems after rebuilding my carbs. Couldn't get a rich enough flame. It turned out when I rebuilt my carbs I hadn't quite got the jet height correct, so I used a brass drift to press the jet further down into the carb.

Also I got fed up of the colourtune in the end and just cleaned the plugs, ran it and then checked the colour of the plugs and adjusted to suit. That said the colourtune was good to get me in the right area.

James

[SGN]

The carb you can't tune could be getting air in somewhere , or the jet is too low (or high) can't remember which way.

http://www.bowtie6.com/other/zenith-stromberg-carburetter-repair/

http://www.buckeyetriumphs.org/technical/Carbs/CarbsI/CarbsI.htm

Cheers
Steve

[markmark2]

Thanks for the replys. Mark

[wilf]

Mark - did you move the colourtune to a cylinder being fed by the other carb? You can't adjust both carbs on the same cylinder as each carb feeds its own 4. I found the attached in my reference file if it helps.

[markmark2]

Mark - did you move the colourtune to a cylinder being fed by the other carb? You can't adjust both carbs on the same cylinder as each carb feeds its own 4. I found the attached in my reference file if it helps.

Hi wilf, thanks again for the help. I put the colourtune on number 1 front right and number 2 front left. weird really...number 2 left where the mixture screw turns indefinitely I get perfect blue and number 1 right cant get blue. Runs ok tho.