Testing transom assembly for leaks

[BillWilliams]

I am getting toward the end of my transom rebuild and want to test the transom assembly for leaks before I drop the engine in place. My idea is to mount the outdrive and use a ratchet strap attached to the transom eye bolts to hold it up while we drive the boat to the ramp (batteries will not be in the boat).

My question is there any concern that could damage the transom since the engine will not be on the other side of the assembly to counter any force from the weight of the outdrive?

Thanks

 

[dubs283]

The transom assy is a stand alone component of the sterndrive package. Having no engine installed won't affect your test. I'm guessing you have the exhaust y pipe in place and the water passage barb blocked off?

You could still use the trim system without the engine in place. Connect the trim pump to a battery and it should work as the trim electrical system is separate from the engine/boat harness

 

[BillWilliams]

Yeah, I'll have the entire assembly put together including the exhaust. I'll try to put the battery in place and see if that works. Thanks

 

[Scott06]

Yeah, I'll have the entire assembly put together including the exhaust. I'll try to put the battery in place and see if that works. Thanks

you will have to hook the trim pump harness up to the battery direct as it usually gets power from the battery cable on the starter lug, which is missing w/o the engine

 

[BillWilliams]

Thanks. I may not worry about the pump and just hold the outdrive up with a ratchet strap as I said earlier because I'll have to pull the drive right back off to put the engine in

 

[tank1949]

I am getting toward the end of my transom rebuild and want to test the transom assembly for leaks before I drop the engine in place. My idea is to mount the outdrive and use a ratchet strap attached to the transom eye bolts to hold it up while we drive the boat to the ramp (batteries will not be in the boat).

My question is there any concern that could damage the transom since the engine will not be on the other side of the assembly to counter any force from the weight of the outdrive?

Thanks

Metal transom or stern of boat? Fill bilge with water after plugging y pipe hole and see if there any leaks.

 

[dubs283]

Fill bilge with water after plugging y pipe hole and see if there any leaks.

This is a terrible suggestion

The idea is to keep water out of the boat, sure a lot of the components in the bilge can handle water for a bit but why subject anything to that?

In order to fill the bilge/boat to be at the water line would take a bit more than you may realize. The load on the hull/trailer would be immense

 

[Scott Danforth]

What are you trying to learn by dropping the boat in the water without the motor and hanging the drive?

Trust that you did a good job on the transom, that it is flat and within specs and you have a new transom seal

 

[tank1949]

This is a terrible suggestion

The idea is to keep water out of the boat, sure a lot of the components in the bilge can handle water for a bit but why subject anything to that?

In order to fill the bilge/boat to be at the water line would take a bit more than you may realize. The load on the hull/trailer would be immense

I have done this test more than once. I don't fill bilge to where water runs into drive shaft opening. You have to monitor water filling, but it works. Then, install motor.

 

[dubs283]

I don't fill bilge to where water runs into drive shaft opening.

That completely negates the purpose of the test

I will add that I don't belive OP's test is necessary however it's their boat and if they want to check their work for leaks their method is sound.

Your suggestion/method goes against more than one principal of operation and can possibly cause more issues than it proves. It is the exact opposite of a logical approach to testing

 

[tpenfield]

Just catching up on your several threads about the transom assembly. Did you do any work on the transom itself? (I might have missed a prior thread)

As far as the test, with a completely assembled transom assembly and outdrive, as well as the exhaust Y-pipe and something to hold the outdrive in a somewhat raised position for trailering, you should only have to make provisions to keep the raw water inlet hose raised above the waterline.

Keep in mind that the boat will float a lot higher in the water without the engine. Post some pictures if you can.

 

[BillWilliams]

I had to replace wood in the transom because of rot.

I've battled the leak since we bought the boat in 2020 and since I have an acquaintance I have to pester to remove and install the engine with his boom truck, I don't want to find out there is something else going on so that's why I want to do the leak test. I figure it's really not necessary but it'll give me that warm, fuzzy feeling. Things are so tight once the engine is in, there's no real good way to troubleshoot a leak.

I simply plan on leaving it on the trailer on the boat ramp.

I'll post a some photos in the next few days.

 

[tank1949]

That completely negates the purpose of the test

I will add that I don't belive OP's test is necessary however it's their boat and if they want to check their work for leaks their method is sound.

Your suggestion/method goes against more than one principal of operation and can possibly cause more issues than it proves. It is the exact opposite of a logical approach to testing

if he rebuilt wood/glass transom OR/AND installed a rebuilt MC Transom assembly (not drive installed), I WOULD. Safer than sorry.... I have used the bilge fill technique with y pipes installed just to be sure o ring didn't slip out when I was installing everything. I have never had a problem. Good luck!!!!

 

[BillWilliams]

Did my leak test on Saturday and no leaks! Hurrah!

Now I need to finish tidying up the bilge and getting cables anchored and such. Also need to get the engine drop in scheduled.

Here are some pics of where things started and ended so far. The board I used as replacement is Coosa Bluewater 26.

 

[BillWilliams]

As Paul Harvey used to say, "for the rest of the story..."

 

[aidanmurphy]

How difficult / time consuming was your transom replacement? I have a small leak coming from the assembly as well and am planning on doing it after this summer.

 

[BillWilliams]

I pulled the engine back in November but did not start on the actual replacement work until the middle of March. I finished getting everything back together over Memorial Day weekend.

If your a DYI type of person who doesn't mind getting dirty, I can't say it's actually difficult, it just work.

I worked on it in the evening when temperature permitted and on weekends. I had the advantage of having the boat in a pole barn at my home so I did not have to travel anywhere.

Cutting out the old fiberglass and wood was a mess with a lot of dust. Be sure to get a respirator and have a shop vac so you can keep cleaning things up as you work.

I also had some fiberglass help from a friend that works for Evercoat who has worked with fiberglass all of his life.