SU Carbs

[ScottieJ]

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.

[scottydouk]

Whats a rough guide to set the air fuel mixture for a Vitara 1.6 8v HIF44 with a 'BFM' needle? screw all way in and how many turns out?
cheers

[twiss]

I think 2.5 turns out is a good starting point, then try outwards from there

[twiss]

Some pictures of SU pipework for Russ24!!! Bear in mind my water rail is a vitara one. they should have the same amount of ports
Excuse the oil leak

This pipe is the brake servo hose



This is where it goes



These two pipes...



the red one goes to the heater control,



the green one goes to the water rail



'scuse the Loopy pipe This goes from the water rail to underneath the front end of the manifold

[Russ24]

*tear to the eye*

im.... so... happy.


thank you twiss...

ladies and gentleman.. i am a effing moron

i had the carb off for 2 days.. i couldnt remember what hell i had to do... or where anything went!
i forget easily. (and im getting worse.)


i work VERY well with pictures. you explain it to me i understand but couldnt assemble on description alone.
pics however.

[ferris]

Hello, does anyone know what side of the carb the vac advance pipe has to go? On the su i have it is just behind the butterfly. Is this the right place or do i need to move it infront of the butterfly??

[ScottieJ]

According to Nigel heads write up on difflock you want it on the air filter side of the butterfly have a read through the first link in the first post and the other links in it. Some of the pictures are lost though.

However I read about a mod to do with the dizzy to get rid of the vac advance completely and increase the amount of mechanical advance the dizzy gives you.

[ScottieJ]

Found it http://bbs.zuwharrie.com/content/topic,91020.0.html" onclick="window.open(this.href);return false;

Also an interesting discussion on timing advance http://www.zukikrawlers.com/showthread. ... al+advance" onclick="window.open(this.href);return false;

Perhaps do the Nigel head vac mod then you could have a play with modding the dizzy to see if some lighter springs help hit full advance quicker.

[dan_2k_uk]

Scottie or Twiss feel free to merge this into the first post

Thought I would add a little write up on changing needle and identifying springs as I had mine apart.

Some springs have a coloured part to identify them but some dont so here is a quick method to show how.

Yes I know I bite my nails to much!

Remove the dashpot damper and the 3 screws holding the dashpot on.




Pull the dashpot off straight to avoid damaging the needle then undo the grub screw holding the needle




Pull the needle out of the piston and you can see what it is (Mine happens to be a BEJ)




Place the dashpot assembly the correct way up and remove the circlip from the top of the piston (This is slightly different on early models)




The whole assembly will now come apart and the spring can be removed




Find something or cut some cardboard 1.5" tall and place it inside the spring on some scales set to OZ's (Watch out for the angry Mrs at this point ) Then zero the scales.




Press down on the spring until it is level with your "something" (make sure you aren't pushing your "something")



I now know his is a red spring

The different springs will produce these values

Red -- 4.5 oz
Yellow -- 8 oz
Green -- 12 oz


Hope this helps as I couldn't find any info on it

Dan

[ScottieJ]

Nice write up Dan, I might have turn it into a write up in the DIY section