i just finished a topend rebuild on a 90 cr250. the previous owner(s) didnt do any maintenance and the valves were stuck partially open from carbon. now the valves dont open at all when i rev the engine and has poor performance at mid-top end.
i've got the manual and i put it together to spec. ive done a couple other CR's with no problems. could something have broken in the bottom end cause the valves were stuck? a timing gear or something?
i've got the manual and i put it together to spec. ive done a couple other CR's with no problems. could something have broken in the bottom end cause the valves were stuck? a timing gear or something?
