Weber Jet Pac for 32/36 4Cyl App

In the past couple of years the quality of our fuel has changed drastically in different regions of the US. It changes from summer to winter and seems to be different in Los Angles or Maine compared to Texas to Alaska. To keep up with the Government mandated leaner, oxygenated fuel we have made 3 increases in jet size to accommodate the new fuel. A properly jetted carb, that worked great a couple of years ago, may have lost some of its performance due to the new fuels. There are several symptoms, needing high idle, hesitation on acceleration, a flat spot around 2500 rpm, or surge a a certain RPM. Any modifications used to increase performance such as headers, electronic ignition, free flow exhaust, snorkel will definitely affect carb performance. It comes without saying that a bigger cam, reworked motor, or a bored motor makes a difference. We all know that altitude and extreme temperature or humidity affects the air to fuel ratio. Now, if any of these factors are combined, there is a