Fuel Solenoid Replacement

[Big Red]

The Yanmar fuel solenoid is sticking according to 2 mechanics. The first Yanmar certified mechanic said it is an electrical issue as the solenoid is getting power all the time the key is on. It got hot and likely burned up which is why it works sometimes and sometimes does not. He's recommending we change replace the solenoid shut off valve, not a cheap option. But, if needed, we will get it done and by a certified Yanmar tech.

A second mechanic was also able to get the engine to run well but it would not stay running. He believes the solenoid is involved as the solenoid gets warm to the touch but is not certain it needs to be replaced. We are preparing to head north in a few months and need to feel confident in the resolution.

Has anyone heard of this and what would cause such a failure (simply asking to learn).

Thanks.

 

[Bill Roosa]

Fuel solenoid?????
There is a shut off solenoid that replaces the (the horror) manual engine shut off cable and knob. It should be controlled from the helm by the "stop engine" button and a 12 volt relay. If the solenoid is "getting warm" then it is "on" and trying to turn off the engine fuel so that would explain the will not keep running part. These things are pretty $$$$ but cables are not........and cables will not leave you high and dry without some warning.......
Disconnect the solenoid electrical and secure the wires so they don't short and see if the engine will run. To stop the engine you just have to manually (more horror) move the lever on the fuel pump that the solenoid did. next check for voltage at the solenoid wires with the ignition in the run position. There should be no voltage at all. if there is the relay or switch (much cheaper) is suspect.

 

[Big Red]

Thank you.

 

[Bill Roosa]

Your welcome
Mechanics need broken boats to have very expensive and easy to replace items to put their kids through college ;-). A $3.00 relay that is really an auto relay fits that bill. Tell the customer the solenoid is always on so of course that means the solenoid is bad not the switch that is turning it on all the time incorrectly.

 

[Big Red]

Makes sense, unfortunately, we already ordered both parts before seeing your informative message. He did demonstrate that the solenoid is functioning intermittently and why he is suggesting replacing it. Guess at this point, we have to trust him. Once we depart the marina, need to feel confident in the repair.

 

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[Don Crowther]

I thought fuel solenoid's required power to let the engine run? I thought when you turned the key off you took the power away from the solnoid and it would shut the fuel off.

 

[Big Red]

Two Yanmar mechanics stated that the kill switch did not turn the power off so the hut off solenoid continued to get power over a long period of time which it's not meant to take, hence the damage to the solenoid/and intermittent operation. However, one wanted to spend hours on additional problem determination; the other suggested replacing the kill switch and solenoid.