As a subscriber and lurker on multiple superhawk sites I'm well aware of the many reports of major engine damage when the adjusters suddenly fail. From what I've read it seems the Honda (and Suzuki) automatic adjusters fail with some regularity, and some times the failures are catastrophic and without warning. A few weeks ago my '98 hawk started rattling very loudly, sounding like a cold diesel at idle and rapping as if in dire need of major tappet adjustment. Oddly, the noise would develop while riding and then sometimes it would go away on its own or when next starting the engine. I suspected a bad adjuster and did some research on OEM and aftermarket replacements. The only aftermarket I found was APE. My mechanic friend of 33 years at the local Honda dealer recommended going with the APE units rather than the OEM Honda units because of his experience with failures of the self-adjusting Honda adjusters. As I understand it, the stock unit is a spring loaded plunger which is free to ride in and out of its case as tension on the chain varies in use. Sometimes the spring breaks and the plunger loses its pressure against the tensioner, other times the plunger will "hang up" in its case and fail to apply sufficient pressure. In either event the cam chain starts whipping around and may even jump off a sprocket tooth. The APE units are manually adjusted and then locked in place; the plunger can not move. However, the labor to install is much more complex because the cylinder head covers and chain guides must be removed so that chain slack between the two cam sprockets can be measured as the tensioner is adjusted. The OEM units are just bolt-on and then self adjust (tank and airbox removal required for the front). It is important, though, to confirm that crank and cam timing are still correct even when swapping out for new OEM units. I now have the APE units and no more rapping diesel noises. This all happened at about 4,000 miles since new.

Rodger

 

You can look under CBR on the main Ape page.
http://www.cbrzone.com/sprockets.html

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