View Full Version : Cracked engine block

06-25-2010, 10:46 AM
New to the forums and new to boat ownership. Long story short I bought my first boat a 2001 Kanga, Not really knowing what all I needed to check out I just took the boat out on the lake and made sure it ran and didn't sink before I bought it. Had the boat summerized and my mechanic noticed the engine block had been repaired with JB weld. He said it would probably be good for years not to worry about it. Well I've put about 5 hours on it since and I was curious about the block so I looked at it while it was running and a steady stream of water was coming out of the side of the block. So I'm assuming I need to replace the block. Not knowing anything about replacing the engine where should I start? Would it be safe to keep running it through the summer? I only paid ~6000 for this boat would it be feasible to put a new motor in it? Really would like to be able to use it for the summer before I have to sink more money into it. Also the interior needs to be replaced but I can live with it for a while.

06-25-2010, 11:04 AM
why not just re-weld it ?

06-25-2010, 11:09 AM
I would go back and kick the guys ass who sold you it. Pretty shady to not tell someone about that. Yes, you need a new engine block JB Weld isn't going to work.

06-25-2010, 11:29 AM
Thanks for the replies, yea I'd like to find the guy, but I guess I partially blame myself for not having it checked out better. The boat had been sitting a while before I bought it, only has about 200 hours on it. When I got it back from the shop I tried to patch a small leak with JB weld but it has only gotten worse, looks like it may be leaking up around where the heads bolt on to the block now. There is no water in the oil. Any ideas what I can expect to have to pay to get this done? This is my first time for all of this so I am totally new and lost.

06-25-2010, 11:42 AM
I think you can buy a GM crate motor for 2000$ have a mechanic swap it for 500$ to 1000$


I think moomba/mc dealer can put a brand new indmar in it for ~6000$

06-25-2010, 11:52 AM
Will a regular GM 350 crate motor work? I was under the impression it had to be a marine motor. The engine seems to run fine other then the water leak so I'm also assuming everything can be swapped over to the new block?

06-25-2010, 12:02 PM
You will need to put everything from the marine engine on... even the oilpan

06-25-2010, 12:06 PM
1- Call Indmar
2- Call a moomba dealer
3- Call a GM marine mechanic
4- Compare options
5- Kill previous owner (optional)
6- Work your way out of jail (optional)
7- Enjoy your boat

06-25-2010, 01:49 PM
There is no water in the oil. Any ideas what I can expect to have to pay to get this done? This is my first time for all of this so I am totally new and lost.

I would call around to local engine machine shops in your area and get a quote on using a real weld on it. It "may" be a $50 job to have a weld done and fix the problems. If there is no water in the oil, you have already won half the battle. Either way, an extra $50 is way cheaper than a new engine. If it doesn't work, it is not that much extra.

If you are fresh water only, you can use any GM 5.7 block. I had an engine out of a car in an older boat that I had; used it for several years without incident. You'll just need to try to match (or exceed) the HP that came with the boat.

06-26-2010, 03:37 AM
I agree. Try to find someone to weld it for you.

james yarosz
06-26-2010, 11:06 PM
If JB weld is used properly it will last almost forever.If you can see the whole length of the crack it can be repaired.you drill a small hole at eash end of the crack only about a 1/6th inch in.then you grind out the length of the crack with a dremmel tool about 1/8 inch wide(not very deep)Make sure it is clean and dry(you may have to drain that side if the block) apply JB weld and let dry for 24 hours.You may apply a second coat over the first coat.I've done many Marine engines this way and never had a leak. Marine engines do not have pressure in the system and the JB WILL hold if done properly.

06-26-2010, 11:14 PM
That is the correct procedure for using JB weld for this application. That would be a very cheap fix.

06-28-2010, 11:23 AM
Thanks for the reply's, I may look into the welding suggestion. Can the JB weld on the block be removed easily?

07-21-2010, 12:24 PM
Ive' been a marine tech most of my life,dont waste time and money trying to weld the block.Its cast iron and near impossible to weld.The crack is from the block(engine)not being winterized properly.This is just the beginning of your problems. The cyl heads are more than likely cracked also(just not shown up yet)you will need to replace the complete engine with an marine engine.All though a cad motor looks the same they wont have the right camshaft and cyl heads to perform correctly.Hope thie helps.

07-21-2010, 08:28 PM
You can pull the heads and have them checked for cracks. There are NDE procedures used for that, and most engine machine shops will do it for not too much per head.

You can weld cast and it works pretty good as boats don't have that high of water pressure in them, not like a vehicle.

Main thing is, drill the start and stop of the crack, and then open it up a little bit.