Stuck valve - cause ???
07-10-2013, 05:14 PM
#11
Platinum Member
When I saw "stuck valve" and 525 EFI in the same sentence, that is the first thing that came to mind ... leaking headers. I know of a couple of new long blocks that were the result of leaking headers. The new design header is not that much better. The specific one's that I know had stuck valve => leaking header had the new style headers. One person actually had the engine back together when someone recommended he get the headers checked ... good thing he did that or he would have most likely trashed a brand new Merc warrantied long block! This was back in 2006 when all of this header awareness was beginning to really gain steam (pun intended).
07-10-2013, 06:49 PM
#12
Registered
Is it a staggered boat? Happen to be the starboard side? Captains call? My buddy has an 08 525 boat and for the 3rd (yes third) time in 300 hours it reverted bad enough to rust the valve stems on the rear two exhaust valves. This boat has new headers on it (within 10 hours) and did it this time recently again. Mercury put a motor in under warranty when the boat was new and said the cause of the failure was a combination of a rigging issue from Fountain and the fact that the silent choice mixed water too close to the collector. This time around the silent choice came off... so fingers crossed. Reason I posted is that the failure happened exactly the way you stated. We ran the boat one week flawlessly, next week we started it for a poker run and it was missing and carrying on the second it rolled over.
07-10-2013, 08:25 PM
#13
Is it a staggered boat? Happen to be the starboard side? Captains call? My buddy has an 08 525 boat and for the 3rd (yes third) time in 300 hours it reverted bad enough to rust the valve stems on the rear two exhaust valves. This boat has new headers on it (within 10 hours) and did it this time recently again. Mercury put a motor in under warranty when the boat was new and said the cause of the failure was a combination of a rigging issue from Fountain and the fact that the silent choice mixed water too close to the collector. This time around the silent choice came off... so fingers crossed. Reason I posted is that the failure happened exactly the way you stated. We ran the boat one week flawlessly, next week we started it for a poker run and it was missing and carrying on the second it rolled over.
