Posted by users Festus and Rayzerman on FJRiders.com on September 23rd, 2012.
https://www.fjriders.com/forums/viewtopic.php?p=171297#p171297
Significant info……. Original pair fittings are 0.275″ thick at mounting holes, with washer head screws having yellow loctite. Best replace while doing a valve check as access is limited on the bike.
WynPro plates were .325″ thick aluminum, however, screws bottom out with ~ 0.175″ under head, thus plates can be 0.25″ material and screws will not bottom out.
On the underside of each plate, are counterbored holes (.375″ x ~0.18 deep) to clear the buttons on the reed valves… these buttons project up ~1mm, so 1/8″ deep is plenty, and the /375″ bores could be smaller without a problem.
Pic below of 2014 valve cover with 2000 miles, reed valves are clean and have self-contained gasket rib all around. No gasket needed, just install flat plate and screw it down. May want to clean carbon off the upper gasket surface of reed valves to ensure full seating (don’t damage gaskets). No need to remove, it matters not if the reeds are dirty on the bottom side (exhaust port side) whatsoever, reeds do not function with plates installed.
