Carburetor adjustment

The vacuum nipple to be connected with retarding diaphragm actuator is now closed, because double diaphragm actuator doesn't appear in the market and the retarding concept had been quitted soon, only for 1 to 2 years interval production of air cooled VW.

But, this closed nipple with often closed hose is so useful to adjust the 34PICT3 carburetor, because the air inlet from this nipple while idling shows the condition so apparently as to know the moment A/F mixture, rich or lean.

Gradual inlet from the nipple would gain or loose rpm, increasing the idle speed means too rich and decreasing does too lean. In short the inlet of air from this nipple can increase only the air volume without any screws rotation adjustment.
This useful method is not reported by anyone in the Web site?

The experience on WEBER 40 DCOM side draft carburetor for over 10 years equipped in PEUGEOT Talbot 205 Rallye, passing the Legal inspection by myself in the government line made me possible to know the mixture ratio and a motor condition.

According to my career, most of carburetor setting scenery the mixture is too rich and the fact caused ill-understandable strange phenomena giving up the precise adjustment for most of the engineers.

The sweetest point exists very narrow and small area on the adjustment screw, so the key to success is to know the condition now is rich or lean exactly! Positioning very near to lean points.

In addition the ill-mixture adjustment affects not a little on the transition to middle speed sometimes even to high speed because of moistened spark plugs.
Anyway the adjustment of idle speed and obtaining stability in combination with transient characteristics to middle and hi speed was in my capability.