Piston help on 94 KTM250sx

[cr125_king]

Hey there. My brother's got a 1994 KTM250sx.He was going to order a new top-end a few weeks ago, but he didn't know what his old piston is(if the cylinder has been resleaved etc). So today he pulled the head off and got these part #'s

ELKO
1961f
67.5(stroke)
and of course the arrow pointing forward

Also the stroke on the outside of the the cylinder says 69.5, but non the top of the piston it says 67.5>whats up with that?

 

[marcusgunby]

I think you are confusing the bore and the stroke.The stroke is the distance the piston moves up and down,the bore is the width of the piston.The bore size is what is on the piston normally.Order a piston with the same size,I beleive Elko is the manufacturer of the piston and has been used in KTMs before so its probably a std one.