Sail Boat Inboard Diesel Engine Overheating

[Petr Merkulov]

I hauled my cape Dory 25D for the first time last weekend to paint the bottom since I just recently purchased it. When I launched it today and was motoring to my moorage (about 5 miles away) the engine overheated three times (at about 3000rpm) and I had to stop the engine and wait while it cooled down. It's a Yanmar 1G 7.5 and I am totally bewildered as to why this happened! Before I hauled the boat the engine was perfectly fine. Anyone have any ideas before I call my expensive diesel mechanic?



merkulov@ix.netcom.com

[Al Levesque]

Is there any chance that you masked the water inlet when you painted the bottom? Or might there be a lot of paint on the inlet?

Al



albertlevesque@cove.com

[Chris]

Al - Any possibility a small little critter might have found a home in your intake fitting? Have you confirmed that your intake hose is not clogged? I would suggest closing the seacock and removing the engine side of the intake hose. You could then open the seacock and confirm the water is flowing unrestricted. If no flow, then remove the hose from the seacock and try and clear the obstruction from either the hose or the seacock. If that does not work, did you check your impeller?

I hauled my cape Dory 25D for the first time last weekend to paint the bottom since I just recently purchased it. When I launched it today and was motoring to my moorage (about 5 miles away) the engine overheated three times (at about 3000rpm) and I had to stop the engine and wait while it cooled down. It's a Yanmar 1G 7.5 and I am totally bewildered as to why this happened! Before I hauled the boat the engine was perfectly fine. Anyone have any ideas before I call my expensive diesel mechanic?

[Warren Moore]

I hauled my cape Dory 25D for the first time last weekend to paint the bottom since I just recently purchased it. When I launched it today and was motoring to my moorage (about 5 miles away) the engine overheated three times (at about 3000rpm) and I had to stop the engine and wait while it cooled down. It's a Yanmar 1G 7.5 and I am totally bewildered as to why this happened! Before I hauled the boat the engine was perfectly fine. Anyone have any ideas before I call my expensive diesel mechanic?

It is probably the impeller. It is the most common cause of engines overheating. It is not a hard job to replace, however if you have not worked on your engine and lack experience, it may be a good udea to have a diesel mechanic do it the first time with you watching. In the future you can do it yourself. You may also want to keep a few spares on board just in case.
Warren Moore
CD28 "Crisscross"



wmoore@peconic.net