exploded piston

[dragon man]

I know its going to sound stupid but my kids love the sled. 1987 exciter 570 liquid cooled, clutch side piston skirt broke apart and I need to know what caused this and if it is and easy fix of cleaning out the bits and pieces and putting in a new piston and rings, there is no scoreing on the cylinder walls and no heat damage, but what could have caused this?

 

[theultrarider]

I would guess that is just rattled itself to death. When was the last time that engine had fresh pistons? Once the clearance gets too big, the piston will slap the cylinders walls hard enough, long enough to break the skirts off. Best and safest way to clean the debris out of the bottom end is to pull it all the way apart and clean it up. If you try to do it without splitting the cases you risk not getting it all out and damaging crank/rod bearing and/or taking out another piston again. Make sure to change out the other piston as well. It will probably break its skirts off soon too.

 

[dragon man]

thanks already have it out and working on it and I wiil replace bothe pistons.

 

[MOUNTAIN-VMAX4]

Non Nicasil

Since the Exciter has non nicasil cylinders, you can have them bored to 10 thousandths over stock for cheap and buy new 10 thousandths over pistons and then your tolerances for piston to cylinder wall will be like new again and no piston slap.