i think we have the same problem. i too had installed exhaust flappers and rebuilt the risers 10 years ago,elevating them higher than the original design. I was not aware of the precaution of holding down the 'stop' shutoff button for a longer period, and did not do so this time. i had the sensation that the engine ran for a second or two after shutdown, and then locked up. My engine is now completely 'locked' and could not be moved with a breaker bar. Examination of the #5 and #6 cylinders through the inspection ports revealed some signs of rust in #6 and a bent rod in #5. i think that the engine may certainly have run backwards for a revolution or two, but where did the water come from if the risers were functioning properly? i think the risers may have developed a leak to allow this to take place. Did you get a price for the necessary repairs? thank you for your information and your help. Will stay in touch.
----- Original Message ---- From: Michael McCartney <[email protected]> To: [email protected] Sent: Sat, October 3, 2009 5:31:13 PM Subject: [UnifliteWorld] Re: HYRDOLOCK for the 3rd time 1978 38' Uniflte w 671 Nauturals I have an 1981 38' with 671's. I feel your pain! My starboard engine has hydrolocked several times. I have replaced the exhaust risers, installed exhaust flappers and have initiated the practice of holding the stop button in for at least five seconds after the engine stops running. I have been told that the problem is that the 671 can run backwards for a second or two if the fuel is not totally shutoff. I am not sure which of these solutions really cured the problem but I have not had it happen again. I now have corrosion in number six and a bent rod. Even with all that it ran fine all summer. I ran it about 400 hours. It just smoked a lot when the engine was cold. The boat is out of the water in Sitka for the winter and I have a mechanic that is going to replace the cylinder lining and the rod .... probably the piston too. What a hassle! -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Michael McCartney Sent: Saturday, October 03, 2009 5:11 PM To: [email protected] Subject: [UnifliteWorld] Re: HYRDOLOCK for the 3rd time 1978 38' Uniflte w 671 Nauturals Are these 671's? -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Alexander Halperin Sent: Saturday, October 03, 2009 12:28 PM To: [email protected] Subject: [UnifliteWorld] HYRDOLOCK for the 3rd time 1978 38' Uniflte w 671 Nauturals Port engine hydrolocked for the 3rd time. Occurred on shut down in calm waters of Avalon Harbour after a 5 minute run to put aboard fresh drinking water. Engine seemed to run for a second or two, then abruptly stopped and locked. New higher exhaust risers had been installed on both engines after previous hydrolock occurrence 10 years ago. Previous 2 episodes had also occurred on shutdown, but in heavy swells after a long run. Why is this happening? alex --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "UnifliteWorld" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/unifliteworld?hl=en -~----------~----~----~----~------~----~------~--~---
