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VFR750 VFR750 is offline
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Join Date: Mar 2004
Location: Windsor, CT
Posts: 1,815
Thanks! I spent an incredible amount of time cleaning. I was, and still am afraid of dirt and grit contamination. Too much invested to let a moment of sloppiness ruin it.

I want to be very clear as to what happens when you let the idler drop down. The cam shaft does not move at all. What happens is the chain goes slack and drops down and towards the intermediate shaft sprocket. A kink forms in the chain. The slack chain actually tries to engage a different tooth on the sprocket. Just one tooth pitch over (down and to the left)

What happens is you don't realize that when you rotate the crankshaft, to get the hidden kink out, you don't rotate the cam, but the kink really doesn't go away. What you really did was reset the number of links between the two sprockets. And the idler locks this new count into position.

And why do you rotate the crankshaft? Becuase the kink prevents you from rotating the crankshaft in the opposite direction. It's jammed. The stage is set, you are about to screw up the rhs timing.

Without being able to see into the case when this is happening, it is hard to get a picture of the actual kink. But it's there. And the results of my experiment proved to me what went wrong on my build.

Wayne's book mentions the risk, but my only criticism is this caution is buried in many long paragraphs, and frankly I missed it. I think a dedicated paragraph and highlighted caution would be better.
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Mike

'82 911SC, SSI, 22/29 tbars, 22F/22R Adj swaybars, Bilstein Sport, Elephant polybronze & monoballs, Cambermeister bar, turbo tierods, Carrera oil cooler, front brake cooling ducts, Sparco Sprint 5 & Recaro SRD PAX seat, Teamtech harness, DAS Sport rollbar.

Last edited by VFR750; 08-02-2016 at 05:42 AM..
Old 08-02-2016, 05:30 AM
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