blown up 2000 cr250 question?

[johntoasty]

Okay so today I decided to tear down my bike after I blew it up a few weeks ago. And when I pulled off the cylinder I realized that the piston was totally shattered but and I am assuming(hoping) that all of the piston pieces went out of the exhaust but I am not sure. But my main question here is do you guys think this cylinder is TOO scored to just put a new piston in or should I go ahead and bore it??

Edited June 12, 2014 by johntoasty

[johntoasty]

?

Edited June 12, 2014 by johntoasty

[Beau 88]

Looks like a crack in the port, and i bet all that piston didn't go out the exhaust it's in the case .

[Kawabuggy]

I recently blew up my 2001 the same way-the piston skirt on the intake side shattered and MANY pieces made it into the bottom end contaminating the crank bearings, and the big end rod bearing, and a piece got between the cases & crank and blew a big crack in both case halves.

 

What I'm telling you is that at a minimum you will need to split the cases & replace both crank bearings & seals, & inspect the crank big & little end rod bearings carefully for metal. If you find anything (as I suspect you will) fix it right by replacing everything that is damaged.

 

I had to have my crank rebuilt, all new bearings & seals, new rod, new piston, re-sleeved cylinder, new rings, ALL OF IT.

 

Looking at the pics of your cylinder I think I would get it replated. But measuring it would give you a much better basis on which to work from,.

[BigBoyBike]

Yeah might as well split the case just to be safe