Power Head Corrosion and Pitting on the block deck

Hello:

I recently pulled the cylinder heads off my 1998 200hp Johnson and found some corrosion/pitting on the block. I attached a few pictures of the engine. I was wondering how I might fix this before I reassemble.

Thank you for any advice.

-Jake

Re: Power Head Corrosion and Pitting on the block deck

looks like salt water has been there, either leaking gasket clean it the best you can.

Re: Power Head Corrosion and Pitting on the block deck

Yes, saltwater damage. I was wondering if it needs to be fixed, or just clean it up and replace gaskets and reinstall the heads? Does anyone know what the feasibility of using JB-Weld or Marine Tex on the block?

Re: Power Head Corrosion and Pitting on the block deck

You could try that stuff, but you would definately want to be sure that it is as flush as possible. If the cylinder head is mounted against it being pitted, it is still flat against it, and it isn't completely pitted out. With a gasket and cleaning the corrosion very well, it should stop it from further damage, and should still perform. But if there is a little bump from the jb weld or whatever you might use, it will cause the cylinder head to not mount flush against the powerhead, and will not work at all.

Re: Power Head Corrosion and Pitting on the block deck

I had the exact same thing happen to my 1997 200HP Ocean Pro 2 years ago. Same side even. Not quite as bad as yours but getting there. The fist tie it happened I had the heads planed, cleaned the block up the best I could and put it back together. I got another 100 hours or so out of it before it started leaking ever so slightly again.

This time I tore it down, took a 12" flat file and worked the block to knock off the high spots the head bolts caused. I then cleaned the block using aluminum weld cleaner and a stainless steel tooth brush. When done I used lacquer thinner and clean rags to finish the job.

Now comes the tricky part. I mixed up a batch of JB weld and used a credit card to apply the JB to the eroded areas on the block. Be very careful on only apply it where needed. Then I took a sheet of wax paper and covered the head, JB and all. I then took a small wooden roller I had laying around used it smooth out the JB weld in the area I applied it to the block. Work the roller back and forth on the area until all the voids are filled and the wax paper is as smooth as a babies behind.

Let it sit over night and remove the wax paper. You?ll be amazed at how flat and smooth the repaired area will turn out. I then spent about an hour with the flat file knocking the excess film of JB off the block. At this point the JB is hard, but not rock hard so its pretty easy to work with a good sharp flat file. With a little patients and elbow grease you?ll be quite surprised at the results you can obtain.

I let the JB set for another day or two before I put the head back on using Aviation sealant on the gasket per the instructions on the can.
I ran the motor all winter without a problem and really don?t foresee the problem reoccurring anytime soon.

Good luck