87 Sailfish 252G engine bracket

[Capt. B]

Boat is new for me. First winter in dry dock and working on numerous issues that I have little experience with. This issue is the engine bracket. Has fins that come off the bottom stern of the bracket and look damaged by retrofitted engines. Fins have recognizable scars from what looks like the engine torquing in reverse. They also appear to be bent upwards. Also I noticed that the 4 bolts that secure the motor to the mounting bracket have a great deal of corrosion. Lastly I pulled the drain plugs (2) from the bottom of the bracket and got between 50 - 100 gallons of salt water. Assume this could be attributed to bad seals in the access plates on the the top of the bracket? Any knowledge or advice? Thanks

I have pictures but don't know how to attach to the post.

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[Capt. B]

Think I got it.

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[Grog]

The plates were for old engines that didn't seal well at the cowling. You don't have that problem now and don't need them, and can finish the job someone started and cut them off. There aren't any scars on the lower units from hitting the plates?

I don't think you'll basically fill the bracket up from a bad access plate. Do you know when the plugs were last removed? Either an engine bolt is not sealed well or the seal is shot between the hull and the bracket. If it's standard bottom paint with the copper it'll react with the Aluminum bracket if any part is exposed which can help the leak issue. You might be able to reseal the motor bolts and check to see if you're filling up with water before pulling the bracket off and resealing it.

 

[Capt. B]

Thanks Grog. There are no scars on the motors and as far as I know, these are only the second pair after the original 175's. The bottom paint used was specifically for metal application. I primed the bare spots first (which there were a few large flakes down to bare aluminum) as well as painted the top portion with white rustoleom. Not sure what you mean about resealing the bracket other than the drain plugs and the top access plates. Understand there are a few bolts that hold the motors on the bracket but is there another area (ie. between the hull and the bracket) where water could get in? Did notice that the caulk between these to areas had gaps in it but I assumed this was just to keep water out of the gap between the two. Regardless that joint has been recaulked as well. Is the bracket not sealed like a fuel tank? Thanks

 

[BobP]

Fill the bracket with water in the driveway, and see where it leaks from, if it does. Put a jack under the rear of the bracket to relieve the transom while doing this.

Give it some time to leak, and fill it up to the top.

 

[HaulinBass]

The plates on my bracket were hitting my motors so I cut them off over 2 years ago, did not notice a thing. Sawzaw with a good metal blade took 5 minutes. Don't forget to file the edges down so no one gets hurt around the swim platform.

 

[Grog]

One common place for leaks is by the engine mounting bolts. How have you make out?

 

[gw204]

Understand there are a few bolts that hold the motors on the bracket but is there another area (ie. between the hull and the bracket) where water could get in? Did notice that the caulk between these to areas had gaps in it but I assumed this was just to keep water out of the gap between the two. Regardless that joint has been recaulked as well. Is the bracket not sealed like a fuel tank?

The bracket does not have a closed tub. The end that meets the transom only has a flange for the bolts...and there's no bolts across the top that I'm aware of. So, if the caulk there had gaps, there's a good chance that is where your leak is/was. Best way to fix that is to pull the bracket completely off, clean the mounting surfaces, apply a fresh bead of sealant and re-mount.

 

[Capt. B]

Very interesting. Yes the caulk was bad where the bracket meets the transom and at this stage I have just recaulked using standard bathroom silicone. Have not been to the boat in 3 weeks but plan to launch next weekend after installing recently acquired Attwood SS scuppers. Had gotten acetyl replacements from West Marine but the locking nut was so loose on the scupper threads that you could pull it off without turning the nut. Thinking that I'll put the whole bracket issue on hold until next season haul out and at that time do a proper reseal of all bolts and gaps.

 

[Grog]

Silicone is not recommended for use under the water line. The seal will not last. If you want a fast fix until next year for the bracket, scrape off the silicone and use 3M 4000. It' not as nasty to get off as 5200 but has the same sealing properties.

 

[Capt. B]

Thanks Grog. The only gap that was sealed with the silicone was the top gap which is about 1' above the waterline. It does get some splash and spray but not continuous. Still think it needs to be redone?

 

[BobP]

The top seam doesn't have a flange to seal against, to speak of, unlike the sides and bottom. My top seam leaks, I get litte water in the bracket though.

Did you look into inspection ports? Is there foam blocks in there ??

And what about the anode? Is there one and is it maintained, must protect the bracket from galvanic destruction.
Same goes for the bcaket as your motor, made of same alumiunm alloy, protected by same zinc sacrifical anodes.

 

[Capt. B]

Yes there is foam inside. As far as anodes, each motor has 2 wedge type on either side of the lower unit, one circular anode above the prop and one bar anode on the motor bracket; nothing i can see for the mounting bracket itself.