honda crf250 timing issue

[ridered36]

I have a 2006 honda crf 250r and I've recently been doing a top end rebuild. I got the vavle seats cut to my vavle s and everything but upon assembly when setting the timing to the factory marks and getting everything torqued to spec. When I try to to cycle the cam it clears the. Exhuast vavle s but once it gets to the intake vavles it locks up. With the cam out of the head I can move the crank and piston through both intake and compression strokes. Idk if it's a problem my intake vavle s or what. If someone can shed so light on this I'd appreciate it. Thanks.

[doug the slug]

It sounds like you've got the cam timing wrong and when the piston reaches top dead center (TDC) the intake valves are still open when they shouldn't be. You have to be sure that the piston is at TDC on the compression stroke (all valves are closed then) when you set your cam timing marks. Remember that there are two TDC possible are you're likely using the wrong one - turn the crank one full turn (ie. 360 degrees) and try again.

[ridered36]

Ok thanks