I am trying to figure out how to set the autochoke time at cold startup on cultus. As per google, its an AISAN 2 Barrel carburetor. and I found a schematic for that as well.
First The Problem:
The car starts fine, with cold idle rpms at about 1.2K on CNG. About 1.5k on Petrol. As soon as a accelerator is pressed, lets say driving till the end of the street, the rpms fall suddenly to about 600 (vibration zone). This happens in a two step, first down to 1k and then down to 600 (as per the 3 step cam profile for choke. Fig1). Probably the vacuum linkage to autochoke lever pulls it back before time, and the choke fails to hold. The rpms settle down to about 900 to 1k after driving about 2 kilometers.
The Mechanic Solution:
I need to tighten choke rpm screw. This would increase idle rpm and heat up the engine earlier thus when choke opens fully, i dont see much of the fall on rpm scale. Strictly prohibits fiddling with autochoke itself as it can damage the bimetallic coil inside. This solution causes rpms to rise upto 2.3k range when on petrol. Did all this in the past. Not feasible in my opinion.
What I think:
The autochoke iteself has a scale on its circumference. If the holding plate is loosen up and the choke rotated counter clockwise, that might help to increase choke time.
Fellows, need your help about what to do. Please advise.