My 75 Hunter 27 is powered by the rebuilt original Yanmar SB8 engine. The water pump system works fine, with new gaskets and impellers etc,...however.....when you shut down the engine and start sailing for the afternoon the engine has a difficult time picking up intake water when you restart the engine after a couple of hours of sailing....the pick problem must relate to the heeling motion during the sail.the boat can be left at the dock for weeks and the intake will start immediately when the engine is started...after an agonizing 3-5 mins at idle the intake water will start after sailing....all pumps, hoses, intakes valves etc are new and working fine.....does anyone else with this boat and engine combination experience the same gremlin...please advise.......
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Maybe....
The suction on the 8hp is not all that great but I would check the following any leakage in the pump suction or clog in the system after the pump would probably reduce the suction: 1) Check that you do not have a hole in your muffler that is leaking water into the bilge. It might take a few minutes to full the muffler up so it spits water spits out the the stern. 2) Try a new impeller. If the impeller is worn it might not suction properly. Are you sure that the right impeller was put in? 3)When you remove the brass plate off the front of the pump see if it's al all worn. There has to be a close tolerance between the front of the impeller and the brass plate to maintain a suction. If the plate looks worn, scratched, bent or weird try replacing it. 4) If in the past the pump sucked up a lot of sand it is possible that the insde of the pump housing is worn or scored. When you take the impeller out look carefully for wear of score marks. If it's not smooth and true the housing needs to be replaced. 5) I would check all of the thru hulls and hoses. If the boat is not in the water take the hoses off and make sure they are not cloged. Make sure tha the thru hull fitting is not clogged and ther aren't have any barnicles in there. You can use a screwdreive ro rout arount in the opening. Also make sure that the valve is open all the way. Als make sure that the intake hose isn't kinked. 6) On the side of the engine behind the alternator is a plate that can be removed. The engine zinc is bolted in the center of the plate. Not the small plate with the zinc but the big plate that the zinc fits on. This is like a little water box. If you take it off you might notice that it's clogged with sand and zinc oxide.y it out and use a vacuum. 7) Check the hoses and the exhaust elbow. They may be cologged. 8) Finally the water jacket may be clogged. You could try to use an acid thype plush to clean it out. I've never done this so I would check with Torrensen or someone who knows before I tried this. Good Luck and let me know how you make out. Howard
The suction on the 8hp is not all that great but I would check the following any leakage in the pump suction or clog in the system after the pump would probably reduce the suction: 1) Check that you do not have a hole in your muffler that is leaking water into the bilge. It might take a few minutes to full the muffler up so it spits water spits out the the stern. 2) Try a new impeller. If the impeller is worn it might not suction properly. Are you sure that the right impeller was put in? 3)When you remove the brass plate off the front of the pump see if it's al all worn. There has to be a close tolerance between the front of the impeller and the brass plate to maintain a suction. If the plate looks worn, scratched, bent or weird try replacing it. 4) If in the past the pump sucked up a lot of sand it is possible that the insde of the pump housing is worn or scored. When you take the impeller out look carefully for wear of score marks. If it's not smooth and true the housing needs to be replaced. 5) I would check all of the thru hulls and hoses. If the boat is not in the water take the hoses off and make sure they are not cloged. Make sure tha the thru hull fitting is not clogged and ther aren't have any barnicles in there. You can use a screwdreive ro rout arount in the opening. Also make sure that the valve is open all the way. Als make sure that the intake hose isn't kinked. 6) On the side of the engine behind the alternator is a plate that can be removed. The engine zinc is bolted in the center of the plate. Not the small plate with the zinc but the big plate that the zinc fits on. This is like a little water box. If you take it off you might notice that it's clogged with sand and zinc oxide.y it out and use a vacuum. 7) Check the hoses and the exhaust elbow. They may be cologged. 8) Finally the water jacket may be clogged. You could try to use an acid thype plush to clean it out. I've never done this so I would check with Torrensen or someone who knows before I tried this. Good Luck and let me know how you make out. Howard
Gung Ho on my old H-27
John, Is Misty Q like My Pleasure?... maybe not as new or shiny as some but safe and sound and for us guys with lots of kids in College one we can enjoy without much guilt. My problem now is that I seem to be power from my little old Yanmar. Maybe a little more smoke out the back end (black) and it seems to overload a little easir. Shaft turns freely and transmission is functioning properly. The exhaust riser cracked at the end of the season so I just replaced it. Maybe I'll try a new injector or something. Would it be work it to have a real mechanic (other than one like me) do a tune up? I do most of the work myself but it's kind of hit and miss. Where do you find a mechanic? The yard where I store My Pleasure isn't much help and I can't find anyone who actually used a REAL mechanic. Any suggestions from you or any one out there would be appreciated. Howard.
John, Is Misty Q like My Pleasure?... maybe not as new or shiny as some but safe and sound and for us guys with lots of kids in College one we can enjoy without much guilt. My problem now is that I seem to be power from my little old Yanmar. Maybe a little more smoke out the back end (black) and it seems to overload a little easir. Shaft turns freely and transmission is functioning properly. The exhaust riser cracked at the end of the season so I just replaced it. Maybe I'll try a new injector or something. Would it be work it to have a real mechanic (other than one like me) do a tune up? I do most of the work myself but it's kind of hit and miss. Where do you find a mechanic? The yard where I store My Pleasure isn't much help and I can't find anyone who actually used a REAL mechanic. Any suggestions from you or any one out there would be appreciated. Howard.
GUNG HO
I suggest you contact your regional Yanmar Distributor to get a recommendation of a nearby dealer who hopefully will have a factory trained mechanic. If I recall properly that Greenlawn is on L.I.; it would be Mack Boring and Parts, Union, NJ. See the Link.
I suggest you contact your regional Yanmar Distributor to get a recommendation of a nearby dealer who hopefully will have a factory trained mechanic. If I recall properly that Greenlawn is on L.I.; it would be Mack Boring and Parts, Union, NJ. See the Link.
W
Warren Milberg
Water pumps
like every else, particularly in 30 yr old boats, wear out. If your water pump is the original, it just may be time for a replacement. Most of the wear typically occurs at the cam inside the pump, which actually creates the suction in the pump when the impeller turns. I know, I know, water pumps ain't cheap, but I know a number of H27 owners (which is a very nice boat!) who've had to bite this bullet and it solved their problems. Good luck with this.
like every else, particularly in 30 yr old boats, wear out. If your water pump is the original, it just may be time for a replacement. Most of the wear typically occurs at the cam inside the pump, which actually creates the suction in the pump when the impeller turns. I know, I know, water pumps ain't cheap, but I know a number of H27 owners (which is a very nice boat!) who've had to bite this bullet and it solved their problems. Good luck with this.
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