Fuel pump seems to work...BUT...

[mhinnc]

Problem: Fuel isn't getting to carb.
Steps I've taken:

- Gas tank was professionally cleaned and several gallons of clean gas placed into tank. The bottom of the gas tank sits 1 ft above and 3 ft behind the Atomic 4. (C&C 30 MKI).

- New 1/4" marine grade fuel line installed from the tank to the engine and double clamped at both ends. Suction was applied to engine side of gas line (before attaching the line to the engine) and gas was freely pulled from tank.

- Sediment bowl was removed, cleaned and filled with gas as much as possible when securely reinstalled.

- Fuel pump was checked by working the baler up and down while the 1/4" copper tubing from pump to carb was removed. The pump outlet was covered with a very small piece of thin plastic (from a grocery bag). When baler was lifted there was suction at the fuel pump outlet going to the carb. When baler was allowed to drop the plastic flew up off of the outlet. (FYI on edit - previously there didn't appear to be suction at the outlet, but a retest shows there is.)

- Carburetor was removed, all jets cleaned (as per Don's video), and reinstalled.

- The fuel pump baler was been worked up and down a gazillion times and has yet to show resistance indicating the carb bowl is filled.

Q1. Would you happen to know what I should try next?
Q2. Is it a normal condition when the fuel pump baler is raised and suction is observed at the pump outlet going to the carb?

Thanks for any insight.

[ndutton]

Check your oil level and smell the dipstick for the odor of gasoline.

[mhinnc]

Check your oil level and smell the dipstick for the odor of gasoline.

Just pulled the dipstick. No odor of gasoline at all. Thanks for the suggestion.

[joe_db]

You can *carefully* connect an outboard tank to the carb to verify the carb works correctly. If you set the tank up above the engine, once you squeeze the bulb to get it going gravity will probably keep it going. Make SURE to turn off a valve or disconnect when finished.
My engine is too new to have a mechanical fuel pump, so I am not really up on them. Adding an electric pump is one fix if you just can't make the mechanical pump work.

[mhinnc]

You can *carefully* connect an outboard tank to the carb to verify the carb works correctly. If you set the tank up above the engine, once you squeeze the bulb to get it going gravity will probably keep it going. Make SURE to turn off a valve or disconnect when finished.
My engine is too new to have a mechanical fuel pump, so I am not really up on them. Adding an electric pump is one fix if you just can't make the mechanical pump work.

I did use an auxiliary tank (outboard tank) with a three way valve before the fuel tank was cleaned (because of a tremendous amount of debris in the fuel from the tank). And that did work. I've considered replacing the three way valve in the new fuel line but am hesitant to have the auxiliary tank as a main fuel tank for obvious reasons. Thanks for the suggestion.

[Dave Neptune]

One of the "check valves" the suction side has failed, has dirt under it or the diaphragm is compromised. Since no fuel odors in the oil should be an easy fix with the rebuild kit.

Dave Neptune

[mhinnc]

One of the "check valves" the suction side has failed, has dirt under it or the diaphragm is compromised. Since no fuel odors in the oil should be an easy fix with the rebuild kit.

Dave Neptune

Dave,
Thank you for the info.

[mhinnc]

Found the problem.

A brief discussion with Ken lead to a solution. There was a bit of air in the fuel line upstream (between the fuel pump and gas tank). I attached a portable marine jerry can hose - with inline squeeze bulb - to the fuel pump and squeezed the bulb filling the sediment bowl and pump completely. The fuel pump baler took only a stroke until it couldn't move any further. The motor cranked immediately. I reattached the fuel line coming from the tank and this solved the fuel pump issue.

[Dave Neptune]

Ken would certainly know more about the A-4 pump than I from experience. However I still feel that a check valve may be weak. I installed on my boat and a few others a new water/filter separator with all new lines from the tank to the carb. By pumping the bale in 3 cases the pump pulled the air through and prime was achieved and then the bowl filled. Once the bowl filled the bale was stuck in the "Pump" position.

Dave Neptune