----- Original Message -----

From: wrjjrs@aol.com

To: Rotary motors in aircraft

Sent: Tuesday, July 14, 2009 3:01 AM

Subject: [FlyRotary] Re: Oly's report on accident

Ok Ed,
Let's do a quick carb-speak check. FLOAT level typically is checked with the carb upside down and the bowl removed. The number is the measured distance from the gasket surface to the highest point on the float unless depicted otherwise in the manual. Remember the FLOAT level is measured with the carb inverted, and the thing to remember is that the higher the FLOAT level the lower the FUEL level. The confusion with the reversed levels is the reason that all the motorcycle manufacturers went to FUEL level only in their specifications. The motorcycle guys gave you a tube which was a simple graduated cylinder, a hose, and a tap screw to put in the bottom of the float bowl. You were supposed to only measure the fuel level. In fact if you look at later model carburetors you will see that the flange that contains the float bowl is cut away in the center so you can see the gasket mating surface. The purpose of the cutaway was to allow you to see the gasket seal surface to measure the fuel level, which used the same reference surface. If you look in the service manual (Kawasaki at least) of a bike with carbs printed in the last 15 years you will see only a fuel level listed. Boy did that cause the mechanics to bitch when they first made the change! When speaking only of the fuel level the understanding is easy. Fuel level high, carb runs rich. Fuel level low, carb runs lean.
Sorry for the long explaination for the very simple concept.
Bill Jepson