Broken piston 89 65

[voodoo]

Over the weekend my motor made some bad noises and shut down.
Upon inspection the lower piston is broken off, at the upper intake port.
It appears as if the ring end gap is in the middle of the port?
Would over reving not under load, cause this ring to be able to spin?
The motor has less than 10 hrs on a rebuild, was it done incorrectly?

 

[voodoo]

Re: Broken piston 89 65

The pistons have a non oem number of 437407, anyone know who made it?
The cylinder was at least honed, maybe bored, hard to tell if and/or why.
If that is a standard sized piston, could it have been bored yet still remain in spec.
Is this a common practice with outboards?
Can I bore 30 over on only the bottom cylinder, as the top two are mint? I will check spec while it is apart.
I will need to really smooth out the inner head surface due to shrapnel, is this a problem?
At least now, with the powerhead removed, I can easily remove the LU to repair the skeg I tore off last month.:'(
Thnx in advance.

 

[tashasdaddy]

Re: Broken piston 89 65

if you didn't have bad luck , you wouldn't have any. let's get a mech in here.

 

[Solittle]

Re: Broken piston 89 65

If the head is scarred you will need to replace it.

Yes you can bore out only one.

Have you taken it apart yet? That may give you a better indicationof why it failed.

What was the max rpms when you over reved it?