SU Carbs
Posted: Thu May 06, 2010 12:35 pm
Thought I'd start a thread to answer all SU carb related questions, I'll keep updating it with more info as I find more articles etc.
Vehicle, Carb, Needle, Spring, Adapter Needed
SJ410, HIF38, ADS, RED, NO
Sj413/Samurai, HIF44, BDL, RED, YES
Vitara 1.6 8v, HIF44, BFM (although I have read that a BBZ works better?), YELLOW, YES
Nigel heads Heated adapter write up with links to Vacuum mod
http://forum.difflock.com/viewtopic.php?p=165433
useful site
http://www.sucarb.co.uk//Technical.aspx" onclick="window.open(this.href);return false;
Burlen Part Numbers:
BFM Needle -- NZX8060
Yellow Spring (For later ball bearing type carbs) -- AUD4398
Inlet Gasket -- AUD4706
Manifold Gasket -- AUC4279
Tune up info
Do all the usual things, check plug gaps, timing etc.
First you need to make sure you are using the correct needle and spring ^^^^^ info is all up there!
Then run your engine up to temp and check the timing is correct
http://sucarb.co.uk/technical-hif-type- ... ng-general
http://sucarb.co.uk/technical-hif-type- ... ing-single
Don't forget to make sure your dash pot is full to the correct level and preferably the correct grade oil, straight sae 20 weight oil is best and what you'll find in a bottle of SU carb oil.
When adjusting the carb blip the throttle and let is settle between every adjustment.
how to tell that your mixture is right when tuning by ear. Once the engine is up to temperature remove the air filter and use a screw driver to slowly lift the piston 1-2mm while it's idling and listen to what the engine does......
If it stumbles and the revs drop you are too lean so enrichen the mixture. (don't forget to blip the throttle and let it settle)
If the rpm picks up slightly (50rpm or so) peaks and then drops back to idle you are about spot on.
If the rpm picks up and continues to rise then you are running too rich.
I sort of do a combo of the above and also listen to how the engine picks up when you move the throttle, a few quick blips of the throttle and a steady rise etc.
Vehicle, Carb, Needle, Spring, Adapter Needed
SJ410, HIF38, ADS, RED, NO
Sj413/Samurai, HIF44, BDL, RED, YES
Vitara 1.6 8v, HIF44, BFM (although I have read that a BBZ works better?), YELLOW, YES
Nigel heads Heated adapter write up with links to Vacuum mod
http://forum.difflock.com/viewtopic.php?p=165433
useful site
http://www.sucarb.co.uk//Technical.aspx" onclick="window.open(this.href);return false;
Burlen Part Numbers:
BFM Needle -- NZX8060
Yellow Spring (For later ball bearing type carbs) -- AUD4398
Inlet Gasket -- AUD4706
Manifold Gasket -- AUC4279
Tune up info
Do all the usual things, check plug gaps, timing etc.
First you need to make sure you are using the correct needle and spring ^^^^^ info is all up there!
Then run your engine up to temp and check the timing is correct
http://sucarb.co.uk/technical-hif-type- ... ng-general
http://sucarb.co.uk/technical-hif-type- ... ing-single
Don't forget to make sure your dash pot is full to the correct level and preferably the correct grade oil, straight sae 20 weight oil is best and what you'll find in a bottle of SU carb oil.
When adjusting the carb blip the throttle and let is settle between every adjustment.
how to tell that your mixture is right when tuning by ear. Once the engine is up to temperature remove the air filter and use a screw driver to slowly lift the piston 1-2mm while it's idling and listen to what the engine does......
If it stumbles and the revs drop you are too lean so enrichen the mixture. (don't forget to blip the throttle and let it settle)
If the rpm picks up slightly (50rpm or so) peaks and then drops back to idle you are about spot on.
If the rpm picks up and continues to rise then you are running too rich.
I sort of do a combo of the above and also listen to how the engine picks up when you move the throttle, a few quick blips of the throttle and a steady rise etc.