Gentlemen, start your diesels

July, 1999

By Tom Snyder

I have never personally changed my raw water impeller. You read it right – even though my Yanmar has well over 35 hours on it. I’m still an impeller virgin. I used to lie about it, as in: “Yes, Ted, I also leave my impeller soaking in vegetable oil…” or, “Really, Sandy? Well I prefer using a hose clamp to keep the blades in line.” We lie when we hurt inside.

The worst it got was June ’98 in a Portland bar. A guy wearing a brand new West Marine captain’s hat told me he was thinking of having a mechanic replace the raw water impeller on his new boat. He was so cute and trusting in his special hat that I just had to do something to feel better about myself. So I said to him what dozens of men have said to me: “That’s crazy. Do it yourself. If you don’t know how, you’d better learn. It’s basic seamanship.”

The captain looked quite sad so I was beginning to feel better. I went on. “It’s so damn easy, but Jesus, don’t forget to get a good seal, and dammit, don’t let a blade break off and get sucked into your cooling system.” I saw the same guy a month later and he had sold his brand new Catalina. How do you think I felt?

At my raw water impeller support group, I learned that the classic avoidance technique is to routinely purchase replacement raw water impellers. Guilty as charged. Last February, upon waking from a classic diesel-based nightmare, I mail-ordered my fifth replacement kit just to be on the safe side. I actually believe that I am better than all of the other members of the support group because I really do plan to use one of those impellers. This, apparently, is what we like to tell ourselves.

The antidote to fear is information. Accordingly, our group leader suggested that we take a day-long hands-on lesson in diesel maintenance. I went to a training center in March. Many of the attendees wore captain’s hats, so I was on my best behavior. Our two instructors, between them, had about 13 fingers and didn’t find me funny at all. But I had come to learn. I took vast notes, all in preparation for the finale of the class when I would be personally changing the impeller on a lab model of my very Yanmar. I wrote down all of their helpful tips like, “Never run your diesel under no load for more than 10 seconds if you love your engine” and “Never let the fuel tank fall below 7/8ths full.”

After seven hours of class, I was ready for my big moment. They wheeled in brightly painted Yanmars on brightly painted dollies. I told the instructor, Vinny, that the impeller was my area of interest. “Is it hard to do?” I asked. He looked at me like I was the guy formerly known as Prince and said, “If you don’t know how, you’d better learn. It’s basic seamanship.” Then he stared at the diesel for about a minute before he told me that we couldn’t do it. What? We can’t do it because on this model, to remove the impeller you have to first remove the generator. And on this particular model, the generator is “wicked hard” to reseat properly.

When I got home that evening, my wife and kids watched me put down a huge bag of impeller replacement kits that Vinny sold me at a discount. They watched me carefully. “Well,” I said. “I’m cured!” And I really am. Now, it’s summer. I can walk around my boat with a happy heart. I have yet to replace a raw water impeller, but if anyone asks I just look a little disappointed, squint to look for any weather building from the southwest, and explain about the damn generator.

Television producer Tom Snyder (“Dr. Katz”) lives in Cambridge, Mass. with his wife, Anne, and children. He sails his Island Packet 350, Blue Moon, out of Hingham, Mass. and Peaks Island, Maine.