Carb Factory Settings - Whatdoes this mean?

[nheather]

I've just finished sealing a troublesome Mach 28 and want to put the carb back to factor settings.

For the Sub Throttle Needle Valve the manual says this

Withe adjustment screw in place, close off the throttle body against the screw. Very gently screw in the needle valve until it closes off the supply fuel nozzle and is prevented fomr re-openingby the entry of the needle valve in the centre hole of the fuel nozzle (work with great care with this one - we are looking for minimal frictional contact between both parts). RE-OPEN VALVE 2.5 TURNS

My immediate question is what does 'close off the throttle body against the screw' actually mean.

Cheers,

Nigel

[mixmasterjay]

turn the screw clockwise untill it stops (closed) and then turn the screw 2 and a half turns open mate

[nheather]

Many thanks, I got that bit - it comes after the 'close off the throttle body against the screw' bit that I don't understand.

Does it mean I have to hold the throttle closed and then start turning the needle?

Cheers,

Nigel

Edited April 16, 2010 by nheather

[fraggs]

keep the throttle closed then turn screw in until you feel very light resistance then unscrew 2.5 turns

[mixmasterjay]

i think that bit means the adjust idle screw so there is no gap (looking down the carb with the airfilter off ) but im not sure on that bit at all lol

[nheather]

Many thanks - final question.

The throttle stop is currently set at 1mm gap with throttle closed. Should I set the STNV like this or should I remove the throttle stop so that the throttle can close all the way?

Cheers,

Nigel

[mixmasterjay]

keep it at 1mm mate other wise the engine will cut out as soon as the thottle is released

[nheather]

keep it at 1mm mate other wise the engine will cut out as soon as the thottle is released

Yes I appreciate that. My question was whether the STNV should be set with the 1mm gap or whether I should temporariliy remove it (since it was siad that the adjustment should be done with throttle closed).

Cheers,

Nigel

[fraggs]

just the throttle slide closed not the idle stop screw, set at idle screw at 1mm then with carb throttle slide closed adjust STNV

Edited April 16, 2010 by fraggs

[nheather]

Great - thanks for the help.

Cheers,

Nigel

[mixmasterjay]

i would say it means by throttle closed is at idle tbh mate so you will need the 1mm gap otherwise when you are setting the hsn and the lsn the engine won't be able to idle and you wont be able to change the engine seetings while its running , ive always set my needles from factory when the engine is running and its the only real way of telling how the settings you are making that difference

sorry i hope that makes sense mate lol my head ain't working today lol

fraggs has sorted it lol

Edited April 16, 2010 by mixmasterjay