I've got a leak from the Yanmar 16 HP engine in my 1979 Watkins 27 that makes the cabin reek. I've had it checked (and I thought repaired) by the crew at a local marina as well as by another mechanic all to no avail. It seems to be fuel, not oil. They've changed the fuel pump, changed the fuel filter, and say they've checked it over and still we have a problem. I can't get my wife to come back aboard until I get the smell fixed. Any suggestions?
Mark Matthews responds:
Thanks for the question. Sorry to hear about the problem. Although your wife probably isnít interested, diesel fuel and engine oil have different smells, and the ability to discern between the two can prove useful down the road. If your engine runs and the bilge isnít full of diesel, chances are the problem isnít with a leaky fuel line, although just to be sure you should crawl around and become familiar with your system anyway. Changing the fuel pump and fuel filter probably wonít do anything for the smell. I guess what Iím trying to say is that the problem isnít so much a mechanical one as it is one of ventilation.
There are a couple of things you may want to consider to resolve this. For starters, although blowers are usually found aboard gasoline-powered inboards, installing one on your boat may help draw the diesel smell out. You can also consider installing a fan in the engine room as well to give it a boost. If the engine is situated below the cockpit, try installing a small air vent above it. This will allow another exit for the pungent engine smells, and as a bonus it will allow you to smell if something is wrong with the engine.
How the engine is insulated may also have a part to play in diesel odors wafting about. Ensuring that the engine and the fuel tank are tightly sealed from the main living areas is likely to help. Also, donít rule out ventilation in the main living areas themselves. Consider installing a dorade or a small solar hatch fan. Keeping a fan running at the dock can also help the air circulate.
Finally, keeping the bilge clean also goes a long way toward ensuring that the boat doesnít smell like the recesses of the engine. For more information, have a look at the following article that Kathy Barron wrote for us on Odor Control. Good luck to you.