I have run an ESR CR250 Power valve cylinder........I still have it...The cylinder I have is off of a 1991 CR250 so it is also Nickelsel (Spelling?)...I ran that cylinder for 5 years and all i ever had to do to it was Hone the cylinder and change the piston ....I ran it with a 38mm carb...ESR reeds and a ESR Zepplin pipe....It ran very well and I won a lot of races with that set up.....I would not be afraid to run it again......Regardless what someone posted elsewhere on another forum I ran that setup against some of the newer 310 set ups and it holds it own very well.....
