Idle problem

[Joseignacio]

I have a 1998 Mercury 150HP outboard. The motor runs great. Once I arrive at my destination and shut the motor off for a few hours, its hard for it to maintain an idle. The RPMs go low and it shuts off. I have tried to increase the idle while at home and it works fine. I increased them to about 1000. Once on the ocean it does the same again.......RPMs go low and it shuts off.

 

[CharlieB]

Re: Idle problem

Do you have a water separating fuel filter?

You may have a contaminated fuel supply, at home water will 'settle out' of the fuel and lay on the bottom of the tank, at sea it will slosh and blend with the fuel. The volume of water may not be so noticeable at high speed running but once at idle it can settle in the float bowls and clog the idle jet.

Hitting the enrichener provides a shot if fuel to restart the motor.

Remove the fuel tank sender and drop a weighted hose to the bottom of the tank and pull a sample. If you find water, jac one side of the trailer so the weighted hose can reach the lowest point in the tank, draw off the settled water.

Install water separating filters in the fuel line to prevent any future occurence.

 

[Joseignacio]

Re: Idle problem

I run it at home with a hose connected to the back port used for flushing the motor. Everything runs well at home and at the marina once I get ready to depart. After running the motor to get to a destination and shutting it off, it shuts off when turned back on. At this point the idle becomes very low. I would have to increase the throttle to be able to keep it running and then quickly go back to neutral and engage the forward gear. I do have a water separator external filter and it was replaced on Jan.