Fuel pump failures

[WHD]

My 2008 400 Mule (KAF 400A) destroys fuel pumps. The first one lasted about 150 hours, the next lasted about 75 hours, the next one lasted about 25 hours. The last pump lasted only a few minutes. I have also changed the fuel filter and breather when changing the fuel pump. When I go up a hill or accelerate on level ground oil is sent into the carb and blue smoke comes out the tail pipe. If I back off the gas it will go back to a smooth idle.

It idles and starts with no problem.

[kawzak]

My 2008 400 Mule (KAF 400A) destroys fuel pumps. The first one lasted about 150 hours, the next lasted about 75 hours, the next one lasted about 25 hours. The last pump lasted only a few minutes. I have also changed the fuel filter and breather when changing the fuel pump. When I go up a hill or accelerate on level ground oil is sent into the carb and blue smoke comes out the tail pipe. If I back off the gas it will go back to a smooth idle.

It idles and starts with no problem.

I don't have a mule -but maybe I can help. I have worked on engines for 35+ years. The late model mule has basicially a lawn mower engine. Of those the fuel pump is usually operated off the crankcase pressure. make sure you are installing new gaskets-if the fuel pump is of the type that bolts to the side of the block. next make sure no mud dobber wasps have plugged any holes in the end of hoses or tubes/vents. You mave have oil pumping up into the air filter housing at/by the carb because of excessive crank case pressureblow-by, -blocked vent tube(s), restricted air filter, oil overfill, . As far as life of the fuel pump-there may be trash or sand in the fuel tank rupturing the diaphram.