We have a Tartan 37 and our engine has a problem. Our Westerbeke 50 will run with no apparent problems for two-and-a-half to four hours. Then, with little or no warning, it just quits. We have added an electric pump between the tank and engine, but the problem is still occuring. Last year we ran the engine for 30 hours at 2000 rpm with no problem whatsoever. The only advice we've received to date is to yank the tank—yikes! Can you help?
Mark Matthews responds:
Thanks for the question. The problem you describe sounds suspiciously like a fuel problem and the likely culprit may be a dirty fuel tank. You’ll know by first changing all the filters in the fuel line system. While your hands are dirty, go ahead and change the oil and oil filters too, and check that belt tension.
One way to get to the heart of the mystery is to take a look inside the fuel tank. Hopefully there is an inspection port that will allow you to have access to the inside of the tank. Sometimes there is a sump in the bottom of the tank, it just depends on how your fuel system is laid out.What you’re after here is collecting a sample of what is in the bottom of the tank. If there’s a way to shut the fuel line off at the tank, you can also disconnect the fuel line and examine it for large, clogging particles.
Now is also the time to take into consideration what kind of tank you have. If it’s a steel or aluminum tank rather than a plastic one, corrosion could be an issue. How old is your boat? Is the tank original? If the tank is falling apart from the inside, this could also be clogging the system. Carefully examine any particles you come across and determine whether they are pieces of the tank or just symptoms of bad fuel that wasn't strained before it was added to the tank.
If everything seems in order, the culprit is likely to be air in the fuel line. Air in the fuel line of diesel engines can create a vapor lock that keeps fuel from reaching the injectors. Consult your engine manual on how to bleed the engine. If you keep bleeding the system and air is still getting in somehow, change the banjo washers on the fuel line. These can only be compressed so many times before they cease to function as they were designed to and end up allowing air to get in, even when they're tightened.
Another thing to note is the fuel level in the tank. If the tank has only a little bit of fuel in it and you’re sailing hard on the wind in chop, diesel can slosh around the inside of the tank and allow the fuel line to suck air.
If the tank is dirty, consider using a company that specializes in this kind of thing. But be warned, if the tank is falling apart from the inside, no amount of cleaning is going to keep it from disintegrating. And if the prospect of replacing the tank seems daunting, keep in mind that there are few thingse worse than seeing a piece of suspicious looking corrosion on the tank and then putting your finger through the tank wall while underway.
I’d recommend subscribing to the Tartan e-mail discussion list here at SailNet where you can dialogue with other owners on how they may have solved a similar problem. Just go to this link: E-Mail Discussion Lists. After you get there, just click on T for Tartan. Good luck.