Water leak from engine block

[Cobra Jet Steering LLC]

That is great info CobraJet, I greatly appreciate it. I may tackle this myself as I have heard they are not that hard to get out. In fact, there was a writeup on ehre somewhere that I plan to use. My skills are garage mechanic level so other than a ceiling winch, I should be good. Your thoughts?

Yea why not it makes you one with the boat when you do your own work I have been doing that for decades. Even converted a I O to a sea drive and built several other boats or did a lot of mods like big wide skies next to the pontoons on my pontoon boat. the bow would never go under a wave and the boat turned on a dime I had angled edges on the skies to act like rudders . Oh and I did invent steering for jet boats and p w c's also if I recall correctly.

 

[Seadeals]

As an update, my JB is still holding, no leaks so far. I did have it out of the boat, on a bench at eye level and did surgery-like grinding and multiple applications of the JB weld. I literally used a magnifying glass grinding out the crack.

 

[parkerexpress]

Thats what we did, bought a used Waverunner with the HO motor and replaced the one in the boat. Then we shipped the broken one to PWC in new york and had that rebuilt. When we got it back we put it back in the jet ski and keep it as a backup motor, that we also play with. Unfortunately, the other motor in the boat got the crack and we pulled it and replace it with a SBT motor, it has been rock solid, except it leaks oil from somewhere, I can't find. We didn't use the3 JetSki backup motor, as we have too much fun with it.

Thank you for that info Cybuch

Did you get the Yamaha block or the SBT block? It looks like the SBT blocks are more, but is it worth the extra dollars?

 

[cybuch]

Thats a great question, I will look as let you know tomorrow.

 

[Aaron Tonks]

Parker Express sorry to hear that. I hope mine doesn't do that. So far it only leaks to the outside, not into the oil. For anyone else scrolling through with a cracked block, I had a large crack that I repaired may 2019 with Belzona. $300. But way better than JB weld and a lot less than a new motor. It has held up all summer, about 50 hours. Even if this fails eventually (knock on wood) at least it bought me some time. 1 season down.

 

[Seadeals]

Very nice @Aaron Tonks, very nice. That’s exactly how I feel. It is buying time (maybe for as long as we own the boat). If not, certainly no regrets. It buys time to shop a deal on a waverunner or SBT replacement.

 

[parkerexpress]

Parker Express sorry to hear that. I hope mine doesn't do that. So far it only leaks to the outside, not into the oil. For anyone else scrolling through with a cracked block, I had a large crack that I repaired may 2019 with Belzona. $300. But way better than JB weld and a lot less than a new motor. It has held up all summer, about 50 hours. Even if this fails eventually (knock on wood) at least it bought me some time. 1 season down.

By the time I got this boat the crack was almost 7 inches long. Like you said, if you catch it early you may get by forever especially if you drill out the ends like you did.

Can you give me pointers on getting the motor out? The lifting of the engine, bolts for the mounts, and hoses/wires are not my concern. The drive mechanism in the back that goes out to the impellers is not something I am familiar with. I would love some picture and explanations on how that all comes apart. If I know that info I feel I can swap this out myself next year. I am gonna run it a few mores times like this until i can afford the new block.

Thank you

 

[Aaron Tonks]

I bought a winch from harbor freight, mounted it to the ceiling of the garage, backed my boat in, disconnected the hydraulic lifts from the engine hatch, tilted the hatch way back and tied it off so it wouldn't fall. The impeller connection is just a slip connection with a rubber gear between the engine and impeller, when you lift the engine up it will just separate. Not much to it. Lift the engine out at an angle with the front higher. When I disconnected the wires, I took a picture of each connection before I disconnected it. There are a lot of them. Took about 3 hours to pull the engine. I just lifted it up to the ceiling and did the work right there on the boat. I used a dremel to remove the paint and roughing the surface. Then drilled a 1/16 hole at the ends of the crack. Ended up being 3 holes. Then ground down the crack between the holes. ( V'd it out) Then used a heat gun to heat up the aluminum block and to also dry up any water that may have been inside the crack. (I did the repair in May, it was only 60 in my garage) Then applied the putty, tried to smooth it out the best I could. It was hard to tell how thick or thin it was, so I applied it thicker just to be safe. Then put a shop light near it to keep it warm. Belzona said they have had a lot of success with their product and even have a YouTube video of how the fixed a truck engine block.
Hope this helps.

 

[parkerexpress]

I bought a winch from harbor freight, mounted it to the ceiling of the garage, backed my boat in, disconnected the hydraulic lifts from the engine hatch, tilted the hatch way back and tied it off so it wouldn't fall. The impeller connection is just a slip connection with a rubber gear between the engine and impeller, when you lift the engine up it will just separate. Not much to it. Lift the engine out at an angle with the front higher. When I disconnected the wires, I took a picture of each connection before I disconnected it. There are a lot of them. Took about 3 hours to pull the engine. I just lifted it up to the ceiling and did the work right there on the boat. I used a dremel to remove the paint and roughing the surface. Then drilled a 1/16 hole at the ends of the crack. Ended up being 3 holes. Then ground down the crack between the holes. ( V'd it out) Then used a heat gun to heat up the aluminum block and to also dry up any water that may have been inside the crack. (I did the repair in May, it was only 60 in my garage) Then applied the putty, tried to smooth it out the best I could. It was hard to tell how thick or thin it was, so I applied it thicker just to be safe. Then put a shop light near it to keep it warm. Belzona said they have had a lot of success with their product and even have a YouTube video of how the fixed a truck engine block.
Hope this helps.

That is great info Tonks! I appreciate you taking time to post that. Since my motor is way past repair it's good to know that I could put out fairly easy and put the other one in. Now I just have to determine if I want to get the Yamaha reman block from SBT or get a new build with the SBT machined block. They warranty the new block for two years and the Yamaha block for one year but there is a considerable price difference. And I will have to put the engine on a bench so I can swap over all the accessories too. I've heard that takes a couple of hours as well.

 

[Jon D]

Four years after an engine in boat JB weld job which cracked and started seeping again my engine started running a little strange and I have a milkshake in there. I guess I’ll be getting a new engine.

 

[Seadeals]

Awww man, that stinks. I am sorry to hear it gave up. I am hoping four extra years still made it worth it for you. I did mine in April of 2017. Here is mine as of today. I keep a close eye on it. Still holding so far. Do you know how many hours you put on it since the repair. That and thermal cycles probably affects it more than calendar time. It stinks that used waverunner pricing is so high right now.

 

[Jon D]

Awww man, that stinks. I am sorry to hear it gave up. I am hoping four extra years still made it worth it for you. I did mine in April of 2017. Here is mine as of today. I keep a close eye on it. Still holding so far. Do you know how many hours you put on it since the repair. That and thermal cycles probably affects it more than calendar time. It stinks that used waverunner pricing is so high right now.
View attachment 158440

My aftermarket hour meter stopped working at some point and I don’t have anything to read from the engine computer so not sure. I’d guess maybe 200 hours since I found the crack. I probably should have done more although not sure it would have helped.

 

[Jon D]

This is a picture of it today

 

[WREKS]

It may be possible to find and repair a crack path from water to oil in this area. But now the engine and cylinder head have to be removed. Then the cylinder water jackets need to be cleaned and examined. The crankcase is a low pressure so jb welding may be possible. I would be optimistic.

 

[Jon D]

It may be possible to find and repair a crack path from water to oil in this area. But now the engine and cylinder head have to be removed. Then the cylinder water jackets need to be cleaned and examined. The crankcase is a low pressure so jb welding may be possible. I would be optimistic.

Thanks for the optimistic thoughts. I’m fairly handy with mechanical things and do my own basic maintenance but don’t have the tools, time or trust myself to tear into one of these. I can’t even fit the boat in my garage so I don’t even think I’m going to take on removing the engine just not quite sure where I’ll be able to get anything done with it up here in southwest NH.

 

[WREKS]

To be sure, it is a task. But I do not think the crankcase is a throwaway.

 

[Seadeals]

Wish you were closer. I have the perfect setup for engine pulls now.

 

[Jon D]

Wish you were closer. I have the perfect setup for engine pulls now.
View attachment 158577

That is nice, sounds like with these SBT engines something like that might be real useful. Frustrating that there doesn’t seem to be better options.

I noticed in your picture that you didn’t need to JB weld back past the temp sensor. If you look at my picture it definitely cracked back past there so keep an eye on that.

 

[WREKS]

It is also possible that the water-in-oil and the water leak are unrelated. You might try air pressurizing a disconnected water cooling line and listening for sound in the oil cooler. If you do not hear any sound, the water-in-oil may have been been caused by an overheated and momentarily warped cylinder head. Ever optimistic!

 

[Seadeals]

Thanks. I think I found the crack right after water started leaking through (within 10 hours or so). It was very small. Here is a pic. I know it will continue; but still hoping catching it so early and adding that JB to take the thermal cycle stress will keep going strong. I will keep an eye on the other side of the temp sensor. This pic is so close up you can see the excess metal from the parting line of the mold just to the right of the crack. Along that mold line is where the crack forms. The crack is the dark line perpendicular at the top of the vertical metal ridge.