2003 Yamaha F 200 Fuel problem

[tpuckett]

I have a 2003 F200. For the last couple of years it has had a intermittent problem. While at idle it will run out of gas. Pump the primer bulb and it will fill back up with gas and start. It will some times run for a few minutes than die. It seem to be much worst the hotter the temperature is. Not as bad in the winter. If I can keep it above 2000 rpm it runs great. I have had 5 so called marine mechanics look at it. I have replaced the anti siphoning valve. All the filters replaced. The low pressure fuel pump replaced. The fuel cooler checked and cleaned. All fuel lines replaced and checked for leaks. What am I missing

[boscoe99]

How about the pressure relief valve on the output side of the low pressure pump? If failed open intermittently then the fuel will just loop around and go back to the LP pump inlet instead of filling the VST. Has it been replaced?

Will the motor run normally as long as someone is pumping the primer ball?

As a test you can clamp off a hose in the fuel return side of the low pressure circulation system to take the relief valve out of the equation. See how it operates then. Recognizing that intermittent problems are difficult to find. Easy to solve when found. Just hard to find.

[tpuckett]

Pressure releif valve

I am being told that it has been checked and is OK. Your second question about someone pumping the bulb. Yes that works well. I almost think I have a air leak some where but I can't find a fuel leak or smell any fuel.

[99yam40]

fuel will not leak out if it is under a vacuum(on suction side of the pump).
might look for a way to pressurize what all you can for testing

a piece of clear tubing installed in different places while testing might help pin point where air is present

[tpuckett]

Air Leak

I believe I will get some fuel hose and hook it to the engine fuel filter. Then put the other end in a fuel can. That way if it cures the problem I can just start checking every thing from the tank till I find the problem. If it runs out of gas I will know its some where on the engine.