This will ruin your day/week/month/season

[Eric Wettschreck]

Crappies and perch are biting so I went out to get a few. 10 seconds across the lake my 70 Johnson died. I got it offa the lake and this is what I found when I took the head off.

I know these motors have a habit of overheating the upper cylinder. Here's the head.

The upper piston comes out of the block about a 1/8 inch. This I don't understand. I know I have to take it apart and go through it but I don't get why one piston strokes so much farther in the block than the other 2. Hopefully I'll figure it out when it's all apart. Any ideas???

[DTro]

Ouch!

Been there done that.

When I had mine rebuilt, the mech rerouted some cooling line per some sort of recall or something like that due to a known issue. Then I disconnected the VRO.

Sorry to hear of your troubles Eric.

[Wish-I-Were-Fishn]

Bad bearing that supports the crankshaft might cause one end to have more travel? Loose screws on the bearing cap?

[DTro]

Yep, looking again, it doesn't look like it overheated, more like a bearing failure.

[Eric Wettschreck]

I was thinking that too, but..........The piston doesn't seem to have any free travel in the cylinder. I'd think if the bearing was that failed I'd be able to move the pison against the crank and have a bit of free travel.

Time will tell. I have to take it all apart and figure it all out. Once it's in pieces I'll know for sure what happened.

[DTro]

Looks awfully similar to WWG's when he tore it apart:

[Eric Wettschreck]

They look so similar it's almost scarey. Check out the piston markings. Almost identical.

Do you know if WWG's was a bearing fail? I'll know for sure once things are all apart, just curious.

[DTro]

Yes it was the needle roller bearings. Those marks were actually the bearings getting pounded into the head.

[Eric Wettschreck]

Weird, good to know, tho. Not good it happened to WWG but good to know. You can see where a needle got wedged between the pison and the cylinder. Check out the lower part of the piston.

I'll have it all apart in the next couple days. After seeing the pic of his piston and knowing what mine looks like, I'm very curious to see if I have a needle bearing left on the crank or wrist pin.

[Rick G]

I would also say needle bearing failure on the shaft. I had My 100hp merc blow 2 seasons ago and the bottom piston also came out of the sleeve and tore itself up on the head when the crank bearings failed. I feel your pain thats for sure .

[hanson]

I had a ring break on my 60hp Johnson and the results look the same. Basically if any piece of metal starts bouncing around, thats what you get.

Here's a few questions for you Eric...

1 - First trip out this year or have you had a few under the belt?

2 - When did you last clean the carbs?

3 - Winterize? Any sort of winterization process?

4 - Gas... Fresh? Last years? Add Stabil over the winter?

When my motor went it out, it was Day 1 of my trip to the Sturgeon Excursion 3 years (??) ago. So the first day I ran the boat that year. I've been trying to figure out if it was a maintenance thing on my end that caused the problem, hence my questioning.

[Eric Wettschreck]

Chris, this is a pretty fresh motor. I rebuilt it a couple years ago.

Not the first trip out. I've had it wet plenty of times this spring.

Carbs get cleaned yearly if they need it or not.

I winterize it pretty good. Go through things quite well prior to putting it away.

It gets seafoam every tank.

Like I said, i'll know more in a couple days when I get things all torn apart.

[TruthWalleyes]

That looks like my first spring trip two years ago

Never did fix that motor, but downgraded to a lower HP motor that was available and in my price range.

I'm blaming me for running too much stabalizer and leaning out the gasolene, then running her to detonation on the first trip.

[Eric Wettschreck]

She's all torn apart and sitting on my workbench. It's a goner. The upper cylinder rod cap bearing decided to no longer be a team player. It's repairable, but I'm not going to. The crank will need machining, new cylinder sleeve, piston kit, bearing kit, gasket kit, etc. I'll part it out, sell what I can, and take my losses.

Here's the rod, piston, and what's left of the sploded/melted cap bearing.

Crankshaft. Notice the cap journal on the right. That's the upper cylinder. She's toasted.

Last but not least, here's the damaged cylinder.

[CAMAN]

Ouch!!!! Sorry for your loss...

Quick question, do you let the motor run out of gas on occasion? From my experience that is where most of the top cyclinder problems stem from. The top cylinder is usually the first one to lose fuel, and more importantly lubrication and will kill a motor if done enough times.

[Eric Wettschreck]

Good question, and the answer is no.

I know this motor wasn't very fuel efficient and I had 2 tanks in my boat. I was always checking them. As soon as one would get down to aboot 1/4 I'd switch to the full tank.

[boatfixer]

I feel for you man! Mrs Boilerman is prolly gonna have to kick it up a notch, possibly get a part time jay oh bee so's that you can get backs on the waters!

[Wish-I-Were-Fishn]

Sorry for your loss. Hopefully you can get back on the water soon. At least you weren't on a major fishing trip when it went.