Water leaking into bbilge from stern motor mount

[#4 on Bucket List]

Just finished trailering my 29R, 2011 from Anacortes to Northern Ca (860 miles) Since launching there is constant slow water leak from the port stern motor mount. Yard verified leak but tells me they have never heard of water coming out of a motor mount. Pulling the boat tomorrow. Would appreciate any thoughts.
Ted Bowler

 

[knotflying]

Where water is coming out is quite often not were it is coming from. I would find it hard to believe that any of the bolts into the hull are the source, but stranger things have happened. Is it possible that during production someone used a bolt too long and pierced the hull and did a patch and it is now leaking? Is it possible that some road debris bounced up and penetrated the hull in that area?
My past experience with the R-29 has been that the exhaust fitting bolts have corroded and water starts to leak in from there. This is a bad situation and needs to be addressed. However, that's a long way from the port engine mount, but worth examining. Before you take the boat out of the water, I would make sure that the water is definitely percolating from the mount and not running along something and showing there.
Let us know how things progress.

 

[Irish Mist]

Yes this is the first I have heard of a leak from a motor mount. I agree that it is most likely from another location, however you need to keep an open mind as anything is possible. If possible post some pictures as well.
Good luck, I hope it is something minor and a simple fix.

 

[#4 on Bucket List]

Knotflying and Irish Mist hit the nail on the head. After pulling the boat (a 2011) out of the water we found that the exhaust fitting flange had an approximate 1/32" gap between it and the skin of the boat. In an attempt to remove it 3 of the four bolts securing it broke with almost no effort on the screwdriver. The forth bold (top forward) was intact. All three of the broken bolts were rusted through. We cleaned and repacked the flange seal, replaced the bolts and that seems (??) to have solved the problem although there is still some water weeping from the motor mount. We are hoping the weeping is residual water and it is diminishing its flow. My concern now is how many compartments did the leak on the starboard stern fill while traveling to the port engine mount and how to get the water out of those compartments. Although there was water in the compartment housing exhaust fitting there was no water in any of the other stern compartments.

 

[knotflying]

A) Did you use 316 stainless bolts? B) did you make sure the fitting was bonded?

 

[#4 on Bucket List]

Yes to both Knotflying and thanks for the thoughts.

 

[edSB]

i am having water seep into the bilge via the port motor mounts. I had already replaced the corroded bolts on the exhaust flange. I found that i now have corroded bolts on the bottom of the stern thruster. Any suggestions on getting underneath the stern thruster to replace bolts?

Ed

 

[baz]

As an aside... and further thoughts on future materials... it would be nice to have non-rusting ceramic screws/bolts as strong as SS ones to solve these type of problems. What a thought now... 😉

 

[dclagett]

One thing to consider. On my RT25SC the motor mounts are attached to the hull with lag screws. I assume that the hull has encapsulated wood under the motor mount where the lag screw penetrates the hull. If the RT29 is the same, that wood may be soaked and will need to be dried so it does not rot. I would ask the RT factory the makeup of the hull under the motor mount. If it is wood and it is wet you can try drying the wood by removing the lag screw over the winter layup.

 

[knotflying]

i am having water seep into the bilge via the port motor mounts. I had already replaced the corroded bolts on the exhaust flange. I found that i now have corroded bolts on the bottom of the stern thruster. Any suggestions on getting underneath the stern thruster to replace bolts?

Ed

Bolts under the stern thruster? Not to sound facetious, how do you see bolts under the stern thruster that are leaking. Could the water be coming in from the outside seal?

 

[BB marine]

One thing to consider. On my RT25SC the motor mounts are attached to the hull with lag screws. I assume that the hull has encapsulated wood under the motor mount where the lag screw penetrates the hull. If the RT29 is the same, that wood may be soaked and will need to be dried so it does not rot. I would ask the RT factory the makeup of the hull under the motor mount. If it is wood and it is wet you can try drying the wood by removing the lag screw over the winter layup.

I agree 100%. I have seen this Topic and cringe at the thought of water coming out of a motor mount. I may not be understanding the statement but I am assuming water is weeping out of the anchor point of the motor mount. dclagget Is right on, if there is water that has made its way into the stringer, the water needs to get out. The engine bed unfortunately is supported with wood and the anchors are SS lag bolts. I found this out last spring when I was checking engine alignment and found out that the installation of the engine was done improperly from the factory. The engine installation technician didn't center the engine mounts on the engine bed. So now the engine has no more starboard lateral movement for proper side to side angular or parallel alignment adjustment. In order to make a starboard alignment adjustment I need to move the engine mounts to the proper location . ( added to my to do list winter 2018 ) ( Added to my Cutwater QC over looked list)
Port side Motor mount


Starboard Side






I removed a bolt thinking it was a machine bolt threaded into a metallic material ( common practice after the 90's because of so many rotten engine beds and the evolution in the marine industry of no wood should be used below the water line.) to find that it is in-fact wood. If I had the issue at hand I would try to follow the path from the water leak to the engine mount. I would assume (my opinion ) that the water leaked into the stringer grid in the aft but did not drain into the center bilge. It made its way into the stringer and you have water in it now. Water that needs to be drained out at the lowest point.

This is a Cutwater stringer but I assume very close to the tugs.You can see the motor mount is the low spot of the complete stringer. If any part of the stringer was not set properly and sealed properly to the hull water could infiltrate into the stringer. The water from the exhaust thru hull leak may have not drained properly and leaked into the stringer.
http://www.tugnuts.com/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=50106

 

[edSB]

i am having water seep into the bilge via the port motor mounts. I had already replaced the corroded bolts on the exhaust flange. I found that i now have corroded bolts on the bottom of the stern thruster. Any suggestions on getting underneath the stern thruster to replace bolts?

Ed

Bolts under the stern thruster? Not to sound facetious, how do you see bolts under the stern thruster that are leaking. Could the water be coming in from the outside seal?

I have a flexible video endoscope (add this to your must-have list of tools) and observed the corroded bolt and water ingress.http://www.tugnuts.com/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=65684

 

[knotflying]

I can't tell from the picture, is water actually coming in. Water does accumulate in that spot and it may be rusting from that standing water.