Johnson 140HP Rebuild????

[MASTER Brian]

A friend recently picked up a boat with a 1984 Johnson 140HP Outboard. A trip or two to the lake and the boat had been running well, then of course the dreaded stuck ring. We compression checked the motor and 112, 112, 110 & 0. I pulled the head on the bad side and found the busted ring as well as a busted piston on the bad cylinder. The cylinder above this was badly caved in, either from a bad spark plug or a loose head gasket seal and water in the cylinder. The edges of this piston also looked very rough.

Spent a few hours yesterday stripping the motor down to just the bare powerhead assembly, before splitting the cases, he wanted to run it by the machine shop today to see what they said and to find out what size pistons we needed to order. Apparently, the machinist said the motor had already been rebuilt and bored 30 over. In order to do anything more, he was told he needed to find some pistons that are 64(?) over or find another powerhead.

My understanding was 30 was the most you could go on these, is there a chance he can go more? If so, is that even ok? What about re-sleeving the cylinders? The machinist didn't mention that, but I thought he had done that on my E-XP150 years ago when I had to rebuild that.

At this point he's weighing his options, can we find a good powerhead that he can use within his budget, does he involve his attorney.....

The motor is a J140TLCRD

 

[emdsapmgr]

The factory used to make .040 over pistons for your crossflow. 438988 piston and rings. Those superceded to 5006704. Both part numbers now discontinued. There are a couple of U.S. dealers that still have some new stock left-enough to do your engine. Likely, you will need to rejet your carbs to blow additional fuel into the cyls to keep the engine cool. You'll have to figure just how much more that should be.

 

[ondarvr]

I would cut my losses and sell it for parts, then buy another motor.

 

[1983 ercoa 21']

Does wisco make the pistons your looking for?

 

[oldboat1]

What's his budget, and who's he going to sue? Let's see -- 30 yr old motor. I would find a sister motor, and keep the current one for parts. All options open (mechanical, not sure about legal), and chances are there will be a good runner between the two. Always have the option of selling off extra parts later, if desired.

 

[MASTER Brian]

Not sure if he could sue the seller, he said he might talk to attorney. I know there are lemon laws here, but I believe that doesn't apply to individuals selling to individuals. I had a similar situation happen when I bought one of my boats. Had it a few weeks and lost a ring, but I didn't blame the seller as it had been running great, turns out it was a bit carboned up and if I knew then what I know now I might have been able to save it with a good decarb. My motor had never been opened either and appeared very tight. His on the other hand has very apparently been opened on multiple occasions with loose bolts, stripped spark plug, etc. Probably some things that should have been disclosed, but who knows if the seller even knew....... At this point, I'm just trying to help a friend out.

Not sure if a piston, wiseco or not, is made that large. There might be the option for a sleeve, but by the time he does that and buys the other parts, he's probably close to cost of sending in this block and getting one back professionally rebuilt with warranty. No idea as to his budget, but he probably strapped himself just to buy the boat a bit. He acted as though he could do around a grand or a little more.

 

[Guest]

Sue the seller?, you'd spend less money rebuilding and/or replacing the motor.

You can still get an aftermarket set of piston rings through GLM, Sierra or the like.
Those old 99 cu. in. cross flow bubble backs have been built for years, and parts are plentiful. I wouldn't give up on her yet.

 

[schematic]

just have that cylinder resleeved. not a big deal!