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ninjunk · January 20th, 2015, 10:29 AM

If you look in the upper corner of this picture

you can see on the cam lobe that the slightly darker line that indicates where the cam was rubbing the follower, continues dark and at the same width all the way around the cam. If the valve clearance was correct, i'd expect to see that line show up dark on the lobe face, but get lighter where it wraps around the back side of the base circle.

Its hard to tell from the pictures, but seeing a dark stripe that was consistent color and width all the way around would tell me that the follower was riding with spring pressure instead of closing and coming off the cam. Given the design of this system, i'm guessing this is an incredibly common occurrence, and a theory of why these bikes have a lot of cold starting and 'carburetor' problems.

January 20th, 2015, 10:29 AM	#69
ninjunk Lostcause enthusiast Name: Graham Location: Austin, TX Join Date: Jan 2015 Motorcycle(s): 2000 EX250F Posts: 178	If you look in the upper corner of this picture you can see on the cam lobe that the slightly darker line that indicates where the cam was rubbing the follower, continues dark and at the same width all the way around the cam. If the valve clearance was correct, i'd expect to see that line show up dark on the lobe face, but get lighter where it wraps around the back side of the base circle. Its hard to tell from the pictures, but seeing a dark stripe that was consistent color and width all the way around would tell me that the follower was riding with spring pressure instead of closing and coming off the cam. Given the design of this system, i'm guessing this is an incredibly common occurrence, and a theory of why these bikes have a lot of cold starting and 'carburetor' problems.