Because of the Service Bulletin on carburetor floats, I weighed my floats at 5.6 grams prior to them being exposed to any fuel and before my first engine run-up.
During first run-up and after warm up, I did a carburetor balance and with full throttle, I had a 5040 RPM. On that day, I shut down and shortly after did another run-up with like results. Prior to start, I notice the electric fuel pressure was 3.2 psi. However, during run-up, I didn't record engine pump fuel pressure.
After the first run-ups, I readjusted the prop to attempt to achieve 4950 RPM.
Five days later, I ran the engine again. With an 1800 RPM, the engine fuel pressure was 5.3 psi. However, within three minutes of start, I had fuel being blown onto the canopy. I shut down. I discovered that both carburetor drip pans were full of fuel. My first thought was that I had defective floats. I dropped the float bowls and both were full of fuel. I allowed the floats to dry and re-weighed them. The weight remained at 5.6 grams per pair of floats which are within tolerance.
I called Lockwood and spoke to an individual who asked me to do a float check by putting fuel in the bowls to determine that the side pins were above the fuel surface which would indicate floats are good and are less than 7 grams weight. My pins appear to be resting on the fuel surface. Thus, I was confused because the weight is within tolerance but the pins are touching the fuel rather than above.
The individual at Lockwood also said that perhaps my prop was causing a vibration. Accordingly, I reset the prop so both blades are the same.
I also emptied the bowls and reinstalled them and turned the electric fuel pump on. When the fuel pressure stabilized to indicate the needle seat had shut off the fuel flow, I turned off the pump. I removed the bowls and measured the height of the fuel which was just over one-half inch from the top. At the 3.2 psi, the needle seat functions.
I re-ran the engine and with-in three minutes in idle, fuel was again in each tray. I shut down.
During some research, I located an article by SKYDRIVE from UK which has a picture of a good and a bad float. This indicates the good float will have the pin at the fuel level. Thus, I am confident my floats are good and my fuel pressure is good.
HELP. Since my floats are good, what could be causing the flooding of the carburetors?
During first run-up and after warm up, I did a carburetor balance and with full throttle, I had a 5040 RPM. On that day, I shut down and shortly after did another run-up with like results. Prior to start, I notice the electric fuel pressure was 3.2 psi. However, during run-up, I didn't record engine pump fuel pressure.
After the first run-ups, I readjusted the prop to attempt to achieve 4950 RPM.
Five days later, I ran the engine again. With an 1800 RPM, the engine fuel pressure was 5.3 psi. However, within three minutes of start, I had fuel being blown onto the canopy. I shut down. I discovered that both carburetor drip pans were full of fuel. My first thought was that I had defective floats. I dropped the float bowls and both were full of fuel. I allowed the floats to dry and re-weighed them. The weight remained at 5.6 grams per pair of floats which are within tolerance.
I called Lockwood and spoke to an individual who asked me to do a float check by putting fuel in the bowls to determine that the side pins were above the fuel surface which would indicate floats are good and are less than 7 grams weight. My pins appear to be resting on the fuel surface. Thus, I was confused because the weight is within tolerance but the pins are touching the fuel rather than above.
The individual at Lockwood also said that perhaps my prop was causing a vibration. Accordingly, I reset the prop so both blades are the same.
I also emptied the bowls and reinstalled them and turned the electric fuel pump on. When the fuel pressure stabilized to indicate the needle seat had shut off the fuel flow, I turned off the pump. I removed the bowls and measured the height of the fuel which was just over one-half inch from the top. At the 3.2 psi, the needle seat functions.
I re-ran the engine and with-in three minutes in idle, fuel was again in each tray. I shut down.
During some research, I located an article by SKYDRIVE from UK which has a picture of a good and a bad float. This indicates the good float will have the pin at the fuel level. Thus, I am confident my floats are good and my fuel pressure is good.
HELP. Since my floats are good, what could be causing the flooding of the carburetors?