1989 Johnson 90 H.P Cracked Block

[TyeeMan]

Howdy All,

I'm asking this question for a coworker of a friend of mine, info is a little sketchy so please bear with me.

So apparently this guys 90 horse started having some operational problems, wouldn't idle, generally ran crappy. Fast forward through the tests, the shop pulled the power head off and they discovered a crack in the bottom of the block, not exactly sure how big or exactly where. The guy said there was no catastrophic event, no over heat or anything like that.

Questions -
Is this a "common" problem with that block/vintage? Any one hear of this happening before?

If the crack was "far enough" away from the the bottom crank bearing would any of you consider welding the crack as a viable repair?

The guy can get a refurbished short block for around $2300.00. Is that price in the ball park?

I mentioned re-powering with something newer, maybe even a 4-stroke but I don't think he's interested as the boat (a 1989 as well) pretty well used and he kinda wants to keep it going for a few more years.

Thanks in advance for your help!

 

[Joe Reeves]

Having the aluminum crankcase (block) heli-arced depends on how big that crack is and where it is located. A reliable machine shop could advise whether to go that route or not.

The "short block" you mention at $2300 depends on what you mean by "short block". If you are speaking of a block with the crankshaft. rods, pistons, rings installed with cylinder heads... BUT... no intake manifold or other accessories... yes, that's a good deal. If on the other hand, you're speaking of a bare empty block... I'd avoid going that route.

Keep in mind that normally, if having that present crankcase heli-arced, it would need to be completely dismantled. Check that out with the machine shop.

 

[TyeeMan]

Thanks for the response Joe! I guess by short block I meant block, crank, rods, pistons, heads. Not sure about the intake manifold.

Yep, absolutely the block would have to disassembled in order to weld it, , which of course is added cost.

So by the time this guy pays the shop to disassemble the block, take it to machine shop/welding shop and have it welded, and reassemble the block with the original parts, it almost seems worth it to pay the $2300.00 and essentially have a fresh power head.

 

[flyingscott]

Is the crack right under the cylinder (usually cylinder #4) in the base of the block.

 

[TyeeMan]

I'm not sure. Like I say, it's a co-worker of friend of mine. I personally haven't laid eyes on it.

Is there some significance of a crack under the #4 cylinder?

 

[Faztbullet]

Is there some significance of a crack under the #4 cylinder?

Yes the drain can become clogged and the block will freeze and crack causing a external water leak......there are other issues causing idle and crappy running..

 

[racerone]

I would repair a crack in the outer water jacket with --LUMIWELD---An aluminum brazing rod.------Have had good results with the stuff.

 

[TyeeMan]

Awesome!! Thanks again for the replies, I'll pass them on.