2 stroke vs 4 stroke question

[kingblazer84]

View attachment 91655
These 3 cylinder Yamaha’s are great engines. Just don’t over rev them. This is my 50hp outboard jet. I hit a sand bar at full revs and this was the result. I pulled the head to investigate why the compression was down. It wasn’t idling well, so I did a compression test. The chunk got sucked out and did no cylinder damage. My friend, who was a licensed marine mechanic, said put the head on and run it. Just add extra oil. So I did for that summer. That winter we put in a new piston and rings, on that cylinder, and it’s still going strong.

im really surprised you got super lucky! That I would think would need a sleeve and bore/hone with new piston/s with rings lol good on yeah! full send buddy!

 

[Aquaholic]

View attachment 91655
These 3 cylinder Yamaha’s are great engines. Just don’t over rev them. This is my 50hp outboard jet. I hit a sand bar at full revs and this was the result. I pulled the head to investigate why the compression was down. It wasn’t idling well, so I did a compression test. The chunk got sucked out and did no cylinder damage. My friend, who was a licensed marine mechanic, said put the head on and run it. Just add extra oil. So I did for that summer. That winter we put in a new piston and rings, on that cylinder, and it’s still going strong.

Loop charged? Lol.

 

[Samnjoe]

Is that a hole in the piston?
I'm surprised it ran.

 

[Coyote Spooner]

im really surprised you got super lucky! That I would think would need a sleeve and bore/hone with new piston/s with rings lol good on yeah! full send buddy!

Just a home and new parts. Super lucky. If that chunk stuck around it would’ve grenaded.

 

[Coyote Spooner]

Is that a hole in the piston?
I'm surprised it ran.

That’s a chunk above the top ring land. The shiny part is the top ring. I had a rebuildable long block, if it blew

 

[Hexxen]

Yipes!