Boat U.S. - May 2008 - (Page 27) Indirectly cooled diesel engines are designed to operate at coolant temperatures that are high enough to maintain the lubricating oil at a temperature above 100° C in order to prevent an accumulation of water in the oil which might, in the presence of sulfur in piston blow-by gases, create hydrochloric acid in the crankcase. If your engine is moving the boat at hull speed, 6.5 knots at only 1,500 rpm, there is a possibility that the propeller is too large and is therefore placing an excessive load on the engine. In addition, too large a prop will prevent the engine from reaching maximum design rpm (3,200 in your engine) and therefore the engine will never be able to deliver its full rated power at a time when you might need it. I would not worry about the operating temperature. I would have the tachometer checked for accuracy and if it is accurate, consider modifying the prop to reduce the load it is imposing on the engine. With a clean bottom and with a normal load on the boat, a fully warmed-up engine should be able to reach maximum rated rpm-plus about 50 rpm. the tabs will not eliminate this problem. I believe you will have to replace the tabs. You may choose to install hydraulic-powered tabs or an alternate brand of electrically operated tabs made by Lectrotab (Lectrotab.com). These tabs are constructed of stainless steel with no welded parts and are therefore should be immune to the corrosion problem you have encountered. ally becoming “eLoran” with receivers that will automatically use all available Loran signals, eliminating the need to select a particular chain (See story, page 6). eLoran will also be used in many other parts of the world, providing a vital back-up for the GPS/ GLONASS and forthcoming GALILEO satellite systems. I suggest that you check the antenna connections both at the unit and at the antenna coupler. I have a 2002 Cobia 23.4 center console. The boat had been in the New England area for several years, until I moved to the west coast of Florida. Up north the boat was on a mooring; down here it’s tied to a dock. Upon pulling the boat out for a cleaning, I observed that the trim tab piano hinges were rusting badly and that I had electrolysis on the tabs. The trim tabs are Lenco (electric). I have several zincs on the O/B (Yamaha) that still look like new. I have since put a zinc on each trim tab. Now the tabs feel porous, with some marine growth. Should the tabs be painted? Should I run a ground wire off the tabs, to get the electrical charge from the tabs (and ground where?)? Or should I buy new hydraulic tabs? Wayne Neal Englewood, FL Q: I have an old FishFinder unit that has Loran and it did not seem to function properly for me all of last boating season and at the end of the 2006 season as well. I could usually lock on to two signals but not the third and, as a result, could never get a latitude/longitude reading. I had my unit checked out the year before and it was determined to be fully functional. Is there a problem with Loran? I know the government was thinking of phasing it out and not maintaining the groundbased stations. But I thought I had read somewhere that they changed their mind and were going to maintain them for another 10 years. Do you have any information about Loran? Is there a web site or a phone number to call to find out if/what stations are functioning or if a particular stations is down? I live in western New York. Wondered if anyone still has/uses Loran and if they experienced problems similar to what I experienced last year. Kevin Doell Rochester, NY Q: I have a 2005 Crownline 23, the engine is a MPI 350 Horizon with a Bravo 3. When I bought the boat, they told me there are two water inlets, one on the drive and one on the transom. Now the one on the transom has a seacock for obvious reasons. My last boat did not have this second pickup, so I am not used to opening it at the start of the boating day and closing it the end of the day. Well, one day I forgot to open it before I left my mooring. I was more than 10 minutes out in the middle of Boston’s outer harbor when I remembered. The temp gauge was normal, a little under 175. I had about 15 more minutes to get to my destination, and to stop in the middle of any harbor may not be the safest thing to do. I kept on going and it never overheated! My question is why? Can I leave it closed? I would hate to forget to close it one night and find the hose let go. Please let me know your take on this. Paul Inconiglios Millis, MA Q: A: A: Based on your description of the rust on the Lenco trim tabs, I believe what you have encountered is most likely deterioration of the welded areas at the hinge. When stainless steel is welded, it is common for the chromium content of the alloy in the weld area to be altered, making the weld subject to corrosion. Placing zinc anodes on Your Loran C receiver will continue to be a valuable navigation device. The Loran system has been undergoing a massive improvement with installation of new transmitters, precise atomic-based timing apparatus and in many cases new transmitter towers and back-up power supplies. You can obtain current information about the operational status of the Loran C system on the web at www.navcen.uscg.gov/loran/ LORAN_C_status.htm. The site will provide status information for both the Atlantic and Pacific areas. The comment in the site stating that continuation of the Loran C system is still under study is out of date; the government has concluded that the system is to be retained and further improved, eventu- A: The external scoop connected to the transom of your 2005 Crownline 23 provides an additional flow of seawater to the engine-mounted raw-water pump. This type of additional water supply system is typically used in areas where seawater temperatures can exceed 80 degrees F. I believe you will find that the hose connected to the seacock is attached to a device that feeds seawater from the outdrive’s water pump and from the external scoop to the engine-mounted pump. It is likely that you will be able to operate in the cool waters of Massachusetts without the additional cooling water supply, however, there will be no detriment to operating the boat with the external supply in use. For more of Chuck Husick’s insights, go to My.BoatUS.com/askexperts/askchuck. BoatU.S. Magazine May 2008 27 http://Lectrotab.com http://www.navcen.uscg.gov/loran/LORAN_C_status.htm http://www.navcen.uscg.gov/loran/LORAN_C_status.htm http://My.BoatUS.com/askexperts/askchuck
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