problem with yanmar diesel

pete33458 · 07-10-2008, 09:08

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 · 07-10-2008, 09:18

Sounds just like a clogged fuel filter.

Vasco · 07-10-2008, 09:24

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.

Chuck Baier · 07-10-2008, 10:20

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

Cheechako · 07-10-2008, 12:23

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

bill good · 07-10-2008, 13:51

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

regards Bill Goodward

**David M** · 07-10-2008, 13:56

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 · 07-10-2008, 14:13

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 · 07-10-2008, 16:06

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.

Chuck Baier · 07-10-2008, 16:50

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

**Ex-Calif** · 07-10-2008, 16:53

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

That just let's the crap go somewhere else.

Chuck Baier · 07-10-2008, 17:26

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

bill good · 07-10-2008, 19:32

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

Bill

Chief Engineer · 07-10-2008, 20:38

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

**Ex-Calif** · 07-10-2008, 21:34

Quote:

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.

07-10-2008, 09:08	#1
pete33458 Registered User Join Date: Apr 2007 Location: Jupiter FL Posts: 32	problem with yanmar diesel 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

07-10-2008, 09:18	#2
bstreep Registered User Join Date: Oct 2007 Location: San Antonio, TX/Corpus Christi, TX Boat: 1990 Macintosh 47, "Merlin" Posts: 270	Sounds just like a clogged fuel filter. __________________ Bill Streep San Antonio/Corpus Christi, TX

07-10-2008, 09:24	#3
Vasco Registered User Join Date: Apr 2004 Location: Toronto in summer, further south in winter. Boat: CS36Merlin, "La Belle Aurore" Ben393 "Breathless" Posts: 1,799 Images: 34	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. __________________ Rick I Toronto

07-10-2008, 10:20	#4
Chuck Baier Registered User Join Date: Mar 2003 Location: Where ever the boat is. Boat: Marine Trader 34 "Beach House" Posts: 1,644 Images: 54	Clogged filter or pick up tube in the tanks is most probably the culprit. __________________ To boldly go!! Read about our past and current cruises, the boat, some projects and a whole lot more at Voyages of Sea Trek And Now Visit The New Boats Site At The Beach House

07-10-2008, 13:51	#6
bill good Registered User Join Date: Oct 2006 Location: Brisbane Australia Boat: Crowther windspeed 36' cat Goldrush Posts: 121	yanmars Chech the felt/foam in the air filter. Had the felt come off causing part engin failure. regards Bill Goodward

07-10-2008, 12:23	#5
Cheechako Registered User Join Date: Aug 2006 Posts: 245	or air... bleed system if filters look ok.

07-10-2008, 13:56	#7
David M Moderator Site Helper Join Date: Sep 2007 Location: San Francisco Bay Posts: 2,696	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. __________________ David Whenever I find myself growing grim...whenever it is a damp, drizzly November in my soul...I account it high time to get to sea as soon as I can. -HERMAN MELVILLE, Moby Dick

07-10-2008, 14:13	#8
pete33458 Registered User Join Date: Apr 2007 Location: Jupiter FL Posts: 32	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

07-10-2008, 16:06	#9
DeepFrz Registered User Join Date: Mar 2006 Location: Winnipeg Boat: None at this time Posts: 744	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. __________________ The man who keeps faith with reality wants to act truthfully in the here and now, not to derive a secondhand here and now from a purpose. - Karl Jaspers

07-10-2008, 16:50	#10
Chuck Baier Registered User Join Date: Mar 2003 Location: Where ever the boat is. Boat: Marine Trader 34 "Beach House" Posts: 1,644 Images: 54	Pete, That is a very common problem. Don't just clean that screen, remove it from the pick up like he said. __________________ To boldly go!! Read about our past and current cruises, the boat, some projects and a whole lot more at Voyages of Sea Trek And Now Visit The New Boats Site At The Beach House

07-10-2008, 16:53	#11
Ex-Calif Moderator Site Helper Join Date: May 2007 Location: Singapore Boat: Maxi 77 - Relax Lah! Posts: 2,929 Images: 4	Why are you all advising to remove the pick up screen? That just let's the crap go somewhere else. __________________ Dan Relax Lah! Changi Sailing Club

07-10-2008, 17:26	#12
Chuck Baier Registered User Join Date: Mar 2003 Location: Where ever the boat is. Boat: Marine Trader 34 "Beach House" Posts: 1,644 Images: 54	They serve no purpose except to clog up, which is why the builders eventually stopped putting them in the tank. __________________ To boldly go!! Read about our past and current cruises, the boat, some projects and a whole lot more at Voyages of Sea Trek And Now Visit The New Boats Site At The Beach House

07-10-2008, 19:32	#13
bill good Registered User Join Date: Oct 2006 Location: Brisbane Australia Boat: Crowther windspeed 36' cat Goldrush Posts: 121	YANMAR What is the blockage? Brown or black "goo" is bug. Bill

07-10-2008, 20:38	#14
Chief Engineer Registered User Join Date: Aug 2006 Location: North of Baltimore Boat: Ericson 27 & 18' Herrmann Catboat Posts: 922	That's what your primary filter is for...right?

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