Harvey W. Pointer
Recruit
- Joined
- Jun 26, 2003
- Messages
- 1
I have a fuel delivery problem. I have a 2002 25 HP 2 cycle Mercury motor on a 18 ft. pontoon boat. The motor is not oil injected. The motor will run only a short time on the factory installed 25 gal. gas tank. I purchased a moeller 6 gal. tank and tempo fuel line with new primer blub. I removed all the gas from the orig. 25 gal. tank, removed the tank, gas line & primer blub. I installed the new 6 gal. tank and new gas line with the same results (motor would run only a short time). I moved the new 6 gal. tank to the back top tanning cushion of the pontoon which is about 2 l/2 ft. above the motor and guess what the motor ran almost perfect except at wot. As wot motor did surge slightly. Conclusion weak fuel pump. With tank above motor gravity feed helped deliver more fuel. Conclusion for fix-rebuild fuel pump. Since the fuel pump, carburator, and hand primer is one assembly I had to rebuild all 3 as per Mercury 1998 service manual for 2002 motor. I did not see anything wrong with any of the gaskets, diaphram-leaf valve was in perfect condition. I did notice the routing of the bleed hoses was different in the service manual than my motor. Also, I checked the check valves in the bleed hoses and as near as i could tell they operated in only one direction. What is the purpose of the bleed hoses? The service manual did not explain their purpose. Motor still ran the same as noted above. I bought another gas line assembly with another new primer blub and connected directly to the fuel pump input bypassing all fuel line connectors, fuel filter, and hoses. Motor still ran the same. Ran almost perfect with 6 gal. tank on pontoon tanning cushion, but not where the tank should be located. Also, replaced the spark plugs. Can anyone help me with this problem? Please don't tell me to leave the 6 gal. tank on the boat tanning cushion. Harvey Pointer