1229 Wiseco pistons on 1150 Kat

[Carter Turk]

Apparently my break in didn't go so well.
Any thoughts on what caused this? I had the same pistons and break in procedure work fine last time, although the starter clutch destroyed the #1 piston and rod last time, hence the reason for new pistons. The scoring happened on the exhaust side on all three, but #2 had scoring on both sides. #4 piston looks fine. Bike has been out of commission since 10/17.

https://www.flickr.com/photos/146215009@N06/shares/0xvu8D

[Nessism]

Wow. Those pistons look seriously bad. Seized in the bore. That damage is not break in related. Something was wrong.

20181101_153035 by Carter Turk, on Flickr

20181101_153245 by Carter Turk, on Flickr

[TeamDar]

What was the ring gap set at?

[Carter Turk]

What was the ring gap set at?

I didn't set any, had a local shop do the boring and gave them one piston,
they did the last 3mm bore as well and that worked out till SC grenade..
If I had done that after the cylinders were bored, would the gap vary from each cylinder?
This was 400 miles with breakin and trackdays only.

[TeamDar]

Before you installed the piston rings on the pistons did you insert the rings into the cylinders to check the end gap with a feeler gauge? The cylinder bores can vary slightly from one another so the piston ring gap should be set for each cylinder.

[Carter Turk]

Before you installed the piston rings on the pistons did you insert the rings into the cylinders to check the end gap with a feeler gauge?

No, I asked about it when the block was bored, but didn't check.
They'll be fine he said.

[Nessism]

I'm no expert but I doubt the pistons would seize just because the ring gap was wrong.

[TeamDar]

Too tight of a ring gap and the ring has no place to expand when it gets hot. It frequently will break the ring lands or even the top of the piston. The last photo shows a decent chunk of the piston crown broken off. The top of the piston is a smaller diameter than the skirt and normally wouldn’t even touch the bore. Dar

[storm 64]

What puzzles me is #1 piston looks fine... There must have been a oil starvation problem, look at the blue wrist pins on 2,3,and 4... Maybe Big Jay or Rapid Ray will chime in.

[rapidray]

The rings weren't end gapped correctly. Simple as that. Rings expanded with heat, tore up the cylinder till they broke and then all that metal tore up the pistons. You ALWAYS measure and grind the ring end gaps if needed, which is just about always today with aftermarket pistons. I also balance all the pistons I use, to within a tenth of a gram. Sorry for the hindsight help but expensive lessons are usually remembered.
Ray.

[Carter Turk]

Yeah, that was a chunk of wasted change, my fault entirely.
The bore was .03mm clearance, when Wiseco reccommended .02mm, maybe I'm missing a zero.
Now it appears #3 rod bearing is toast.
Is it worth fussing with a welded mid 90's Falicon supercrank to change a rod?

[Steve]

Is it worth fussing with a welded mid 90's Falicon supercrank to change a rod?

I have always heard that there are two ways to do anything: "right" and "over".

Even though you are already in the "over" phase, you still have the same choice.

Worth fussing with a Falicon crank? I will have to let others tell you about that, I have no experience with them.

.