Twin Asian SU carbies

[COFFEY RT51]

Hi,

Im running Twin Asians SU carbies on the corona (4R) But they are in bad need of tuning, as it doesnt idle at all. Does anyone know A: how to tune them? or B: where locally (northern suburbs of Melbourne) would be a good workshop that knows how to tune them? or C: anyone who knows how to tune them and is willing to show me how to do it??

Cheers,
James.

[Redmohawk]

By tune do you mean balance? They should already be tuned if fitted to the motor and running well before. Balancing them is relitivly easy all you need is a length of clear tube about 5 or 6 mm ruffly 3 m long run it in a loop down a 1 m stick run a little water into it to make a home made manometre then fit both ends to vacumbe fittings on carbs. Then ajust throttle balancing screw between carbs to make water level in tube with each other. just turn up idle set screw on throttle a little to improve idle rpm till balanced.

[airfireman1]

Check oil level in carb usually with su carbs the problem is the oil level, causes the slide to stick and also acts as a dampner

[sbfoot]

if you pm me your email address I'll send you a scanned copy of the genuine workshop manual

[allencr]

Just listening to the 'hiss' from each carb with a length of hose will work perfectly to balance them.
With the damper loose, the piston should rise easily/freely & fall with a solid 'thunk'.
But first, don't guess or chase down a carb problem unless you know that the ignition system & compression & valve lash is OK.

[COFFEY RT51]

Ok thanks for all the advice and help. Only problem is the engine wont idle long enough for me to listen to any 'hiss' or fiddle around (which would be mostly guess work) as i dont have anyone around who can keep the car running long enough. (Yes the idle is that bad!!!) Engine was rebuilt about 5000 kms ago if that so not too worried about ignition or compression.

[Redmohawk]

There should be a screw on or near the bracket that your throttle cable runs to , it will put pre load on the carbs to increase the idle speed to a high enough level to keep it running.

[COFFEY RT51]

That sounds like a good starting point!

[COFFEY RT51]

Well i had a good decent crack at balancing the carbs. managed to get them balanced fairly well but could only get them idling at 900RPM any lower and no matter what the fuel mixture was either too rich or too lean...soo might get someone to have a look at it. There was enough oil in them and everything.

[RAAAH23]

jump on a datto forum all the L series engines run SU carbs they will have plenty of infor

[sbfoot]

did the manual come through on your email?

[COFFEY RT51]

"did the manual come through on your email?"

Yes it did thankyou. It was very helpful but still might be worth having someone who really knows what they are doing to a have a squiz at them.

[SilverRA23]

900rpm idle isn't that bad is it? my 18rg manual says the idle for it should be 1000rpm +/- 100 rpm...