Hello, I just picked up a '17 150sx about a month ago. The bike has 91hrs on it but I haven't ridden it. The po said it needed a top end and I could tell by the feel of the kick starter. Anyway, I started the tear down on Friday and yesterday was assembling the power valve and it seems very binding. The center valve moves very easily, but when the end ones are connected it takes alot of force to make the valve move from fully closed to fully open. I don't see how this is going to work after the engine is assembled. I have read a couple articles on the control arms for the two end valves. This seems to be where my problem is. The control arm has a very sharp turn on it. Has anyone tried modifying the the cut out in the control arm? I saw an article about some custom arms, has anyone tried them? Or any other solution to this problem?