Desiel Problems

[Bob Willett]

I have a 40.5 and have been experiencing a problem with my yanmar 4 banger. The engine starts fine and runs well as long as you keep it around 1000 rpm if I run it up to about 2000-3000 it runs for about 5 min then drops down to 1000 or less the stays there and if the throttel has not been moved races back to 3-4 k and then drops off again if I keep the revs up it will eventually die. I had a mech look at it and he coundnt come up with a problem. I have bleed the lines and checked the fuel filters several times. I have checked to see that the vent line was clear also. Anybody out there know something that I might be mising. It is a real inconvience not to be able to run the engine above 1000 rpm.

 

[Tom LaRocco]

It might be....

similiar to a problem I had on my H376. I couldn't get my Yanmar to maintain cruising RPMs (2800) under load. I too changed filters, bleed lines, microfiltered the fuel with no luck. It finally turned out to be a clogged screen at the bottom of the fuel pick up tube inside the tank. Stuff had grown in my diesel and eventually restricted the flow thru the screen just enough to allow the engine to idle or rev in neutral fine but once in gear the engine starved. I cleaned the screen and started using a biocide in the fuel and so far have had no more trouble. Hope this helps.Tom LaRoccoSV Follow the Sun

 

[Les Andersen]

Fuel and Air

Bob,You might check the air filter. The bood says the engine will run great if it has fuel and air. Everyone checks the fuel. But sometimes its just a dirty air filter.Less/v Mutual Fun

 

[Dick Hall]

Fuel Screen

It's the fuel screen. Get rid of it and let the primary filter do its job.I had the same problem - see my post of last week.

 

[Andy Falls]

Hey Willett, clean the tank

40-love and you can't win the match? I agree with the other post, its probably the screen on the pickup tube in the tank. If you don't believe me, just ask Dodd who fixed Vivacious about 10 years ago!Take care of the GFLYC and tell the bridge "hi"s/v Top Secret

 

[red coles]

Sectionalize

Hi Bob: The way to find this kind of trouble, is to sectionalize. try replacing your main fuel tank with a small outboard tank and clean diesel. If trouble goes away, fix main tank,if trouble remains, continue on down the line replacing a section at a time. For instance, you can bypass a filter for test purposes, with a piece of tubing. This method has never failed me. Good luck red

 

[James Bockholt]

Clean Tank

Hey Bob!I will bring some BIOBOR with me in case you have growth in the tank. I keep mine treated, you may need a shock dose.S/V Desiderata