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Discussion Starter · #1 ·
I am assembling my engine and when I went to set the valve timing i found that the LT mark does not line up with the pointer at TDC. I put the left piston at TDC and the mark is way past the pointer. I did not have the rotor off the crank. Is it possible the rotor has slipped on the crank?

 

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John.... Bill Lane will probably be of more help, but I'll try...the 450 rotor is keyed onto the crankshaft, so it is unlikely (not impossible) that it spun.... The 450 in particular has a tendancy want to to "sit" or "continue"a bit past LTDC unless it is physically held on the mark.....Since I ASSUME you are measuring TDC through the plug hole, remember that you are going in at an angle that can make it hard to judge where TDC actually is..... Line up the indexes on the pointer and rotor, hold it in place, align BOTH cam indexes, and close the chain.... If you want to be SURE, remove the rotor bolt, pull the rotor and inspect the key and keyway first..... Steve
 

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Discussion Starter · #3 ·
Thanks Steve, I went out and had another look. You're right, every time I set the piston at TDC then let go of the crank, it would roll CCW a few degrees. I used a small wooden wedge for a hammer handle placed gently between the rotor and stator to hold the crank from turning and it lines up OK now. I should never do this stuff when I'm tired! I used Bill's instructions to set the cam timing and he even mentions that this will happen! Anyway it's timed now and the master link is in and pressed together but not riveted yet. I'm going to sleep on it and re-check it in the morning.

Thanks again Steve and thanks to Bill for the great instructions on setting the valve timing, the service manual is very vague regarding that.
 

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johnnyc14 said:
Thanks Steve, I went out and had another look. You're right, every time I set the piston at TDC then let go of the crank, it would roll CCW a few degrees. I used a small wooden wedge for a hammer handle placed gently between the rotor and stator to hold the crank from turning and it lines up OK now. I should never do this stuff when I'm tired! I used Bill's instructions to set the cam timing and he even mentions that this will happen! Anyway it's timed now and the master link is in and pressed together but not riveted yet. I'm going to sleep on it and re-check it in the morning.

Thanks again Steve and thanks to Bill for the great instructions on setting the valve timing, the service manual is very vague regarding that.

I never thought of a wedge between the rotor and stator.

Since the (cam) timing is not set on compression stroke, the "run by" is minimal - it's much worse when setting the ignition timing. It might have helped some to loosen the tappets all the way. When I do that it usually sits there nicely on the mark for me. You also need to do it before you put the tensioner on.
350's are just as bad, in this context.

Yeah, the manual isn't that much help - it just says "do it" - pretty much like its instructions on how to do the swingarm bushings (simply "remove the bushings").
The Annotated Manual goes into a lot more detail on the cam timing.
 
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