cr250 motor

[redriderarmy911]

Okay my spare bike is is a 89 cr250 and my motor locked up not shure where to go from here. Do I need to have it bored or a sleave not shure about size either and also any helpful tips since this is my first engine work also I think my waterpump went up and caused this does that make sense?

[redriderarmy911]

another pic damn piston has hole though it on exaust side

[redriderarmy911]

Oh yea im new to this site just want to say hey yall

[GPracer2500]

Welcome to the site.

You picked a doosy for your first top-end!

Pretty sure that cylinder has a Nikasil plating. Sure looks like that bore is toast. You could try and scour the cylinder and see if all those blemishes are just ring/piston material that has transfered onto the surface of the cylinder. It's a long shot, but maybe [shrug]. Assuming the bore isn't salvagable, you'll need to either have it sleaved or have it bored and then re-plated. Another option is to find a new (used) cylinder that is still in good conditon.

Don't buy a new piston until you get the cylinder sorted out. You won't know for sure what size piston you'll need until the cylinder work is done.

[redriderarmy911]

Thanx bro I will do that and keep yall updated what do you sugest I scoure it with

[redriderarmy911]

nevermind it is needs to be bored or sleaved but how do I know witch one to do bore or sleave? measure it? it is my spare bike so not trying to dump a ton of $ in it just need to get pointed in the right direction I guess ethier way I have to take it a machine shop right? So they will tell me what to do?

[redriderarmy911]

anyone know a machine shop in Maryland I could call also what am I looking at price wise?

[sixer3]

probably around 140 to bore and re-plate, another close to 100 for a piston and rings and 40 for good gaskets,

[86 Quad R]

either way you go(rebore and plate or bore and sleeve) will cost you approximately the same. the bright side to boring it and sleeving is the fact that the next time all ya have to do is hone/bore and slap a piston in.