problem with yanmar diesel

[pete33458]

I had a problem on my boat this past weekend where, immediately after entering a dangerous and narrow channel late at night (of course), the diesel would drop down to a few hundred rpm, shudder, then go back up to where it was, and repeat. The more throttle I gave it, the more often it would happen. I hadn't refueled for at least 8-10 hours of run time, so I doubt it was the fuel. Didn't seem to me like the right symptoms for air in the fuel lines either. Managed to limp back to the dock, just waiting for it to die completely so I could run aground on coral, but unable to stop in the channel... Anyway, any ideas or suggestions? thanks, pete

[bstreep]

Sounds just like a clogged fuel filter.

[Vasco]

Sounds like fuel. Did your boat get shaken up a bit when you were out sailing? May have stirred up the crud in the tank.

[AnchorageGuy]

Clogged filter or pick up tube in the tanks is most probably the culprit.

[Cheechako]

or air... bleed system if filters look ok.

[bill good]

Chech the felt/foam in the air filter. Had the felt come off causing part engin failure.

regards Bill Goodward

[David M]

With an air leak the engine RPM's will increase for a second and then die. Your description is typical of a clogged fuel filter.

[pete33458]

Just found out, there was a screen filter in front of the fuel pick-up tube, and it was clogged!

Thanks all for your advice. pete

[DeepFrz]

Oh, yeah, take that screen and throw it in the garbage or dispose of it in an environmentally sound way, but get it out of your boat.

[AnchorageGuy]

Pete, That is a very common problem. Don't just clean that screen, remove it from the pick up like he said.

[Ex-Calif]

Why are you all advising to remove the pick up screen?

That just let's the crap go somewhere else.

[AnchorageGuy]

They serve no purpose except to clog up, which is why the builders eventually stopped putting them in the tank.

[bill good]

What is the blockage? Brown or black "goo" is bug.

Bill

[Chief Engineer]

That's what your primary filter is for...right?

[Ex-Calif]

Originally Posted by Chief Engineer

That's what your primary filter is for...right?

That's why I asked.

We do not have glass filters. We have a tank with a pick up (off the bottom) that has an inlet screen. There is plumbing to the lift pump and then through a screw on filter.

I wouldn't want crap going to the lift pump and reckon cleaning the inlet filter is an annual inspection item.

To each their own.