The Sea Trial – and Air Bubbles!
17 September 2011 | St. Augustine Marine Center, St. Augustine , FL
If you have been following our journey from the beginning, you may remember our early issues with air bubbles in our fuel supply. After first noticing them in Little Sodus, we spent days trying to track down the source. We had two different marine mechanic outfits on board. We bypassed all of our fuel line and ran a line directly from one tank to the filters. We still had bubbles. We had Racor send us two rebuild kits for the filters; we rebuilt both filters and still had bubbles. So we proceeded south with air bubbles in the fuel and the Lehman-Peugeot seemed to tolerate them. We told St. Augustine Marine Center about the air bubbles in the fuel line and our concern that the new Yanmar might not tolerate them well. When we got back we asked Danny, the mechanic, about the air bubbles. "They're still there, but the engine runs," was his reply.
Meanwhile, yesterday, while we were in the middle of a day of chores (water tanks refilled, dishes to do, laundry and of course deck polishing in the queue) Bob from Yanmar and Mark from the Marine Center showed up for the sea trial! So we rushed around and got ready, and then Bob says that an anti-siphon device must be installed on the exhaust system to keep seawater from possibly siphoning in to the engine. He said it's standard to install that on a sailboat. Mark does that, and then disappears to another boat. We chat with Bob for a while, then Bud and Bob manage to adjust the throttle so the lever will move the throttle all the way from idle to wide open, another problem Bob discovered. Finally Bob calls Mark to find out that he's just about finished with whatever he was looking at on the other boat, then he's going to lunch! We chat with Bob some more.
Finally, at about 1 PM we actually cast off for the sea trial. So far everything else on the engine checks out. We head towards the Intracoastal Waterway and Bud heads away from St. Augustine. He opens the engine up. One of the major things you check on a sea trial is whether the prop angle is right for the engine. If it's not, the engine won't run correctly at speed and could smoke. Bob calls up with a concern. There's air in the fuel lines! (Yes, we know.) If there's air in the fuel lines the engine won't run correctly at speed and could smoke. Well the engine ran well, but never reached peak RPMs and was smoking (the lower part of our once sparkling stern is now grey). So we came back and we have to deal with the air in the fuel lines and run another sea trial before we know what's what.
Bob and Mark walked off the boat and Bud and I were left to wonder what their intentions were, and what our next action should be. We had pretty much decided that we would deal with the air in the fuel line problem ourselves when Bob came back and said they had a Racor 900 in the parts department. The Marine Center was thinking of putting that temporarily in the line and seeing if it bubbled. Bud and I walked over to the parts department and found that they had two, used Racor 900's. They would sell us one for $150 (about $400 new) and we could take them for the weekend and let him know on Monday if we wanted to buy one (or both). Bob then assured us that one was sufficient for this engine.
Today Bud and I are tackling the air bubble problem one more time. You would think that at least we would have more room to install the new Racor since this is a smaller engine. You might be able to tell from the photo (this is the transmission area and the front wall of the engine compartment) this engine actually sits closer to the front wall where the filters and all the electrical connections are. All the extra room is in back, of course! Bud is going to West Marine for some clear plastic hose. Before we replace the old Racors we are doing one more test that Bob suggested, we are installing a temporary fuel line of clear plastic between our fuel manifold and the Racors, to make certain that the air is not in the system before it gets to the filters. If not, we simply have to figure out how to get the old filters out and fit the new filter in. I'm sure we'll be all day at it.
Oh the joys of cruising!