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Initial Carb setting.. twin SUs BN4

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ronzet

ronzet

Jedi Knight
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As I may have mentioned, now that hte grounding issue is resolved... What should I set the inital carb setting on the jet setting (the big screw on the inside right side of the carbs.. I took it all the way down and then backed off 1 1/4 turns... I rebuilt both carbs with new needle valves, etc
??? /ubbthreads/images/graemlins/confused.gif
Thanks...
 
Let me correct myself... the slow run valve...
 
Hello Ron,

I'm a little confused by what screw you refer to. A BN 4 should have H4 S.U.'s and the mixture is set by adjusting the jet nut. I.5 turns down from the jet flush with the jet bridge.
It sounds as though you have HD carburettors and the screw which adjusts the mixture is turned 2.5 turns down from the jet being flush.
These are a starting point but should be very close if all other settings are correct.

Alec
 
Hello again,

if it's the idle, just adjust both to a nice smooth idle speed, say about 700 rpm, with an equal draw on each carburettor?

Alec
 
Piman, My BN4 is of the later vintage with a six port intake and AUC814s. I corrected my error in the terminology 'slow run valve' above, my apologies.

'tis nice, however, to hear the engine, even briefly, come to life after so many years....

Now to fine tune and consider myself on the backside of the frame off restoration... /ubbthreads/images/graemlins/grin.gif
 
Alec,

As you probably surmised... I am running it for the first time since rebuild and just want to get everything in the ballpark.. or as you might say, on the cricket field??? /ubbthreads/images/graemlins/smirk.gif
 
Hello Ron,

it's a good feeling to get to the end of a restoration. It can be a bit of an effort to get everything running smoothly and to trace and eliminate the little bugs that seem to be there. But with a few miles settling in you should be able to enjoy reliable motoring for many years.
By the way, my S.U. manual doesn't list AUC814's for a Healey, it does list a AUC815 which is H4 type?

Alec
 
Piman,
This darn keyboard of mine is always misspelling... /ubbthreads/images/graemlins/smirk.gif
[ QUOTE ]
My BN4 is of the later vintage with a six port intake and AUC 814s...

[/ QUOTE ]
I actually have AUC 9 14s intalled... AUC 866s are the standard for the late BN4 where the AUC 914 are installed on BN7 and BT7s... both are HD6s. Very little difference between the two types.

And yes it does feel good to get it running. Much left to do before I drive down the road but 'wow' does it sound good.
/ubbthreads/images/graemlins/cheers.gif
 
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