Now that I am sure my compression is to low on my 86 250R if my cylinder is too worn I am thinking about using a new .040 over piston and rings that I bought from my cousin way back when. My question is are these cylinders bored, sleeved, or replaced?
Thanks for the information.

 

First off, what do you mean by too worn? If it is an 86 250R it can be bored to .120" over. I don't know what your bore is at now but I suggest you have it checked before you start spending money on unnecessary things. If however your cylinder is on its last bore and it needs another, you can have the cylinder resleeved. I know that this is a very expensive process though. It costs about $100 just to have a sleeve installed, a sleeve is probably about $100(although I am not sure). You can check the LA Sleeve website(www.lasleeve.com I think). They may have price lists on it. You might be better off with a new cylinder though. There are plenty of used but not used up cylinders out there that would be good enough for you. In fact, I have a few myself for sale if you are interested you can email me about it (Raychalp@aol.com) As far as the "new" .040" over piston you have, you would not be wise to get a sleeve and then bore it 4 times over just to use that piston. That would be a waste of 4 good bores. I suggest you take your 86 cylinder to a place where it can be measured accurately and then go from there. If you have any other questions feel free to email me, I am glad to help.

 

If you do go with a new cylinder I sugest a CT ProX You can even get it in 310cc. Go to www.ctracing.com