Let's face it, working on boats is a b!tch! My back hurts just thinking about it.

The stock teleflex depth gauge that came on my 88 Baja still works fine - almost never loses a signal, even at speed. Buddy of mine has an 89 with the Lowrance version, and his works fine as well.

Well I haven't got the bottom end apart, but removing the heads I found major problems!! The pistons!!! 2 of them are hammered to chit, and 2 more are cracked ready to fall apart in the same spot! The spot where the valve relief is cut into to the piston and the alum is thinner blew out form the top piston ring up!!! Also looks like #3 was running a little lean...

What causes this?

This is # 7
http://i212.photobucket.com/albums/c...psydmcisir.jpg

Head and valve look good

http://i212.photobucket.com/albums/c...psdngtjwjr.jpg

This is # 4

http://i212.photobucket.com/albums/c...pshmwr7xse.jpg

Found the chunk that was bouncing around

http://i212.photobucket.com/albums/c...ps2omqj1ry.jpg

Chamber has a couple small nicks

http://i212.photobucket.com/albums/c...pskzbyjzib.jpg

Then here is #3 and #6, also cracked in the same spot ready to brake off. Weird thing is they are cracked exactly the same...

http://i212.photobucket.com/albums/c...psozzgvuxf.jpg

http://i212.photobucket.com/albums/c...psfj53flxc.jpg

This is the odd bank

http://i212.photobucket.com/albums/c...psw28tbldo.jpg

This is the even bank

http://i212.photobucket.com/albums/c...psokcnbmag.jpg


What the happened?

Ahhh. Refer to my post on the first page of the thread. I told you the plugs looked speckled. Others disagreed. You detonated the piss out of that motor.

I'm sure you hammered the Rod bearings out also.

Just read the beginning of thread....well, you sure did.

You win the middle finger award: Hang it out to see and point it at whom you want.....LOL.

I don't need any awards. I personally feel bad for the guy. It sucks when your stuff blows up. It doesn't take much to make a motor go boom! That is constantly being ran like a car in 5th gear up a hill so steep that you can't see the road under you add to that A/C on max cool and i think you have the workings of a boat motor. Oh and you 350lb. gf in the seat next to you with her 250lb. gf in the back seat (that part is for you SB...)

LOl. Wasn't talking about the OP. I feel bad for him too.

Some tuning/rigging/ or fuel injection issues going on here.

Black Baja hit it on the head looking at the plugs a month ago! WOW! Good eyes.

What causes detonation? Timing was set when I redid the top end. 8 degrees at idle/1000. Used my scan tool to get it into the correct mode. Should the computer pick up knock and adjust timing according?

Still maybe timing off? Low octane gas (even to this engine is only 8.7:1) ?

When I put the new bottom end together (working on that today) I have a choice of 2 complete engines / electronics / computers, sensors. Anything I should or should not use? Maybe not use the old knock sensor?

Thank you for the help.

There are so many things that could have caused the detonation. I'm not saying it leaned out cause at this point the plugs have been idled on and the aren't going to tell you anything. But I'd have all the injectors gone through. Bench test your fuel pump. Make sure the fuel side is 110%. I wouldn't be afraid to do a fuel sample and have it analyzed. Put some fuel in a glass jar seal it and let it sit 2-3 days. Then inspect it for water.

Yep! ;) ;)