130 hp has shrapnel in Cylinder

[HankHenry]

I have a 1995 yamana 130 2 stroke. It has been an excellent engine, with no real problems. I had the carbs cleaned and after starting the engine it rev'd really high and made an awful metal grinding noise. I shut it off quickly and checked it out. First I noticed the fly wheel was locked in place, so I wiggled it until it came free. Now it will do an almost full rotation, then bind. Then I check the prop, it spun freely. So i took the heads off and found the top port cylinder had bits of metal in it that had been smashed between the cylinder and the head. A couple of the pieces look like the metal tubes found in a bearing, they were about a 1/4 inch long. Since it is only in one cylinder and the flywheel still spins smoothly when it does I am guessing it is the bearings from one end of the connecting rod?? To get to this can I remove the crankcase cover, while the powerhead is still attached to the lower unit? Can I leave the carbs on? I'd appreciate any advise on the problem, what problems to watch for during the repair and all other advisement. Thanks!

[99yam40]

will have to pull power head and split case and be taken completely apart to get pistons and rod out.
Does not sound like you have the knowledge to get it done by yourself.
but the service manual will guide you if you want to try
may have hurt crank among other parts also

Did you run the RPMs up or did it do it on it's own?

[boscoe99]

On some Yams you can remove the intake manifold and reed valve assembly to gain access to the connecting rod bolts. You then remove the cylinder head on the side of the motor with the piston problem. After removing the connecting rod bolts the bad piston can be slid out of its cylinder.

Depending on the damage seen to the piston, cylinder walls, bearings, crankshaft journal, reed valves, etc you go from there.

[HankHenry]

The engine rev'd high after the first start from carb cleaning. When I took the head off I didnt see any damage to the cylinder walls and, I don hear any grinding when I hand turn the flywheel. I am planning on giving this a shot unless it isnt possible.

THanks