Hairic
XS650 Addict
Hey guys been awhile since i been on here but knowing you are a knowledgeable group i thought I would bring my issue here. I have a 2009 yz250f, dirtbike, Blew the top end, replaced rings piston and cylinder, everything else checked out fine, put it all together and it fired up, road it around trying to break it in and about 2 hours into the break in it shut down would not start, so i removed the cam cover and checked it out what i found was the cam cover, holding the cam in place was way overtight somehow.. I blame my buddy who was helping me with the rebuild, anyway it smashed the cam saddles on the head down a bit to where the intake caps on the valve could not coully close, andyway i ground those down and got it back together, everything is still in spec, I go to kick it and now it is really hard to kick, like there is just mass amounts of compression built up in there, Now i didnt know anything about valve shims until i did this top end, But it is shimmed correct I do beleive, if any one has an idea why this is I would appreciate it.