tex250r
04-12-2011, 04:06 PM
Hello Everyone, I have a 1988 Honda 250r that Im wanting to rebuild the top end on. I have never rebuilt a 2 stroke engine before and was hoping to come here and learn a few things.
Im pretty sure that this bike still has the stock bore.
Here's what Im dealing with, Ive removed the head and measured the bore with some calibers. I got 2.601 inches and thats very close to 66mm which is the stock bore size for this bike from what ive learned from this forum already?
Ive done some machine work in the past and was thinking about boring this thing out myself. (I have access to a bridgeport) Not sure if I have made up my mind on if im going to do it or not.
I really dont have a ton of money so I was thinking about just boring my cylinder to the next size piston kit. I think you can go 66.25, 66.50, 66.75 or 67.00 and so on. Keep more metal there for later rebuilds if needed, know what i mean? Just depends how much it takes to clean up the scars in the bore right? So heres one of many questions. :)
When ordering a kit lets just say 67mm. Is the 67mm the actual size of what you bore it out to or the actual OD of the piston?
How much gap or room does the piston need? .020,.030,.040 inches?
Ive got a long list of questions but this will get me started for sure. Thanks for your time!
PS if I posted this in the wrong spot im sorry!
Im pretty sure that this bike still has the stock bore.
Here's what Im dealing with, Ive removed the head and measured the bore with some calibers. I got 2.601 inches and thats very close to 66mm which is the stock bore size for this bike from what ive learned from this forum already?
Ive done some machine work in the past and was thinking about boring this thing out myself. (I have access to a bridgeport) Not sure if I have made up my mind on if im going to do it or not.
I really dont have a ton of money so I was thinking about just boring my cylinder to the next size piston kit. I think you can go 66.25, 66.50, 66.75 or 67.00 and so on. Keep more metal there for later rebuilds if needed, know what i mean? Just depends how much it takes to clean up the scars in the bore right? So heres one of many questions. :)
When ordering a kit lets just say 67mm. Is the 67mm the actual size of what you bore it out to or the actual OD of the piston?
How much gap or room does the piston need? .020,.030,.040 inches?
Ive got a long list of questions but this will get me started for sure. Thanks for your time!
PS if I posted this in the wrong spot im sorry!